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Extended List of Publications

Prof. Angeli Sergio
sergio.angeli@unibz.it
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International Papers
 


P27: Journal of Food Science. 2015 Aug; 80(10): M2228-M2240 Presentazione standard di PowerPoint , DOI: 10.1111/1750-3841.12993

Biomedical activity and related volatile compounds of Thai honeys from three different honeybee species

Puttamayutanon P., Angeli S., Thakeow P., Abraham J. and Disayathanoowat T.

Department of Biology, Faculty of Science, Chiang Mai University, Chiang Mai, Thailand

This study investigated the effect of 3 factors (floral source, honeybee species, and postcollection processing) that influence the antibacterial activity, free radical reduction, and other biochemical compositions of different honey types typical of Thailand. Honey samples from 3 honeybee species ( Apis mellifera, Apis cerana, and Apis dorsata) were obtained from 9 floral sources (longan, wild flower, lychee, coffee, sunflower, sesame, bitter bush, para-rubber, and manuka as a control) in different regions of Thailand. These samples were evaluated for both their total and nonperoxide antibacterial activity against 10 human pathogens by agar incorporation technique. Honey samples were further analyzed to evaluate the capacity for free radical-scavenging activity, total phenolic content, and the total flavonoid contents by the 2,2-diphenyl- 1-picrylhydrazyl assay, Folin–Ciocalteu method, and aluminum chloride colorimetric assay, respectively. Furthermore, the volatile organic compounds (VOCs) of Thai honey samples were investigated by headspace solid-phase microextraction and gas chromatography-mass spectrometry analysis. Findings of this study suggest a strong correlation between floral origin and honeybee species on one hand, and differences in %Brix, total acidity, protein content, antimicrobial activities, free radical reduction, phenolic, and flavonoid contents on the other hand. Moreover, VOCs of wild and coffee honey types were remarkably different, depending on the floral source. Both honeys contained characteristics of VOCs, some of which are involved in antibacterial and antioxidant activities.





P26: Entomologia Experimentalis et Applicata. 2015 June; 156(3): 279-289, DOI: 10.1111/eea5.12330

Root damage of apple plants by cockchafer larvae induces a change in volatile signals below- and above-ground

Abraham J., Giacomuzzi V. and Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Bolzano, Italy

Volatile organic compounds (VOCs) mediate communication between plants and insects. Plants under insect herbivore attack release VOCs either at the site of attack or systemically, indicating within-plant communication. Some of these VOCs, which may be induced only upon herbivore attack, recruit parasitoids and predatory insects to feed on the attacking insects. Moreover, some plants are able to ‘eavesdrop’ on herbivore-induced plant volatiles (HIPVs) to prime themselves against impending attack; such eavesdropping exemplifies plant–plant communication. In apple orchards, the beetle Melolontha melolontha L. (Coleoptera: Scarabaeidae) is an important insect pest whose larvae live and feed on roots for about 4 years. In this study, we investigated whether the feeding activity of M. melolonthalarvae (1) alters the volatile profile of apple roots, (2) induces the release of HIPVs systemically in the leaves, and (3) whether infested plants communicate to neighbouring non-infested conspecifics through HIPVs. To answer these questions, we collected constitutive VOCs from intact M9 roots as well as M. melolontha larvae-damaged roots using a newly designed ‘rhizobox’, to collect root-released volatiles in situ, without damaging the plant root system. We also collected VOCs from the leaf-bearing shoots of M9 whose roots were under attack by M. melolontha larvae and from shoots of neighbouring non-infested conspecifics. Gas chromatography-mass spectrometry analysis showed that feeding activity of M. melolontha larvae induces the release of specific HIPVs; for instance, camphor was found in the roots only after larvae caused root damage. Melolontha melolontha also induced the systemic release of methyl salicylate and (E, E)-a-farnesene from the leaf-bearing shoots. Methyl salicylate and (E, E)-a-farnesene were also released by the shoots of noninfested neighbouring conspecifics. These phenomena indicate the induction of specific VOCs below- and above-ground upon M. melolontha larvae feeding on apple roots as well as plant–plant communication in apple plants.





P25: Fungal Biology. 2015 March; 119: 595-604, DOI: 10.1016/j.funbio.2015.03.004

Multilocus genotyping of Amylostereum spp. associated with Sirex noctilio and other woodwasps from Europe reveal clonal lineage introduced to the US

Castrillo L.A., Hajek A. E., Kepler R. M., Pajares J. A., Thomsen I. M., Csóka G., Zamora P., Angeli S.

Department of Entomology, Cornell University, Ithaca, USA

Sirex noctilio is a woodwasp of Eurasian origin that was inadvertently introduced to the southern hemisphere in the 1900s and to North America over a decade ago. Its larvae bore in Pinus spp. and can cause significant mortality in pine plantations. Sirex noctilio is associated with a symbiotic white rot fungus, Amylostereum areolatum, which females inject into trees when they oviposit and which is required for survival of developing larvae. We compared the genetic diversity of A. areolatum isolated from S. noctilio and other woodwasps collected from Europe and from northeastern North America to determine the origin of introduction(s) into the United States. Multilocus genotyping of nuclear ribosomal regions and protein coding genes revealed two widespread multilocus genotypes (MLGs) among the European samples, one of which is present in the US. The other two A. areolatum MLGs associated with S. noctilio in the US represented unique yet very similar haplotypes, with variation primarily in the laccase locus, and the other loci having conserved sequences. These latter two haplotypes were likely from unrepresented source populations, and together with the widespread haplotype introduced to the US reveal multiple A. areolatum haplotypes introduced by S. noctilio and indicate possible multiple S. noctilio introductions to North America from Europe. Our results also showed a lack of fidelity between woodwasp hosts and Amylostereum species. We found a North American woodwasp carrying an A. amylostereum MLG likely introduced by S. noctilio and we report that two Urocerus spp. specimens from Spain, previously only reported as associated with A. chailletii, instead carried A. areolatum in their mycangia. These results underscore the need to study North American siricids and their fungal symbionts as S. noctilio continues to spread in North America.





P24: Chiang Mai University Journal of Natural Sciences. 2015 Jan; 14(2): 175-188, DOI: 10.12982/cmujns.2015.0080.

Development of concentrated strawberry beverage fortified with longan seed extract

Sriwattana S., Phimolsiripol Y., Pongsirikul I., Utama-ang N., Surawang S., Decharatanangkoon S., Chindaluang Y., Senapa J., Wattanatchariya W., Angeli S. and Thakeow P.

1Division of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Chiang Mai, Thailand

Longan (Dimocarpus longan Lour.) is an important and economic crop in northern Thailand. Longan fruits can be consumed as fresh or processed products, such as canned longan, dried longan and longan in baked goods. Longan processing often consists of removing the shell and seeds that are then discarded. In fact, longan seeds contain phenolic compounds, which are antioxidants and free radical scavengers. Therefore, in this research we aimed to extract longan seeds (cultivar Edor) and fortify the crude extract into a concentrated strawberry beverage. The efficiency of two extraction solvents, hot water (70-75°C) and ethanol (70%), were compared. The total phenolic compounds of the crude extracts were 41.2 ± 0.2 and 11.7 ± 0.1 mg GAE/g for hot water and ethanol extraction, respectively. The strawberry concentrate was produced using a freeze-concentration process. The effect of the number of freeze cycles on the quality of the strawberry concentrate was also evaluated. The concentrated strawberry produced by two freezing cycles was selected to develop a beverage according to the richness in vitamin C, anthocyanin contents, and consumer acceptance. The optimized formula of concentrated strawberry beverage fortified with longan seed extract was 5.58% sweetener and 0.42% longan seed extract. This drink contained 248.73 mg/100 g vitamin C, 35.6 mg/100 g anthocyanin content, and 0.17 g/L DPPH free radical scavenging activity. An acceptance test using a 9-point hedonic scale showed that consumers (n=100) accepted the concentrated product with a ‘like very much’ judgment (7.2-7.7 marks). The concentrated strawberry beverage fortified with longan seed extract developed here offers several health benefits and shows potential as a commercial product.





P23: Environmental Entomology. 2015 March; 44(2): 356-367, DOI: 10.1093/ee/nvv013

Behavioral and antennal responses of Spotted Wing Drosophila, Drosophila suzukii, to volatiles from fruit extracts

Abraham J., Zhang A., Angeli S., Abubeker S., Michel C., Feng Y. and Rodriguez-Saona C.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

Native to Southeast Asia, the spotted wing drosophila, Drosophila suzukii Matsumura (Diptera: Drosophilidae), has become a serious pest of soft-skinned fruit crops since its introduction into North America and Europe in 2008. Current monitoring strategies use baits based on fermentation products; however, to date, no fruit-based volatile blends attractive to this fly have been identified. This is particularly important because females are able to cut into the epicarp of ripening fruit for oviposition. Thus, we conducted studies to: 1) investigate the behavioral responses of adult D. suzukii to volatiles from blueberry, cherry, raspberry, and strawberry fruit extracts; 2) identify the antennally active compounds from the most attractive among the tested extracts (raspberry) using gas chromatography (GC)– mass spectrometry and coupled gas chromatography – electroantennographic detection (GC-EAD); and 3) test a synthetic blend containing the EAD-active compounds identified from raspberry extract on adult attraction. In olfactometer studies, both female and male D. suzukii were attracted to all four fruit extracts. The attractiveness of the fruit extracts ranks as: raspberry > strawberry > blueberry > cherry. GC analyses showed that the fruit extracts emit distinct volatile compounds. In GC-EAD experiments, 11 raspberry extract volatiles consistently elicited antennal responses in D. suzukii. In choice test bioassays, a synthetic EAD-active blend attracted more D. suzukii than a blank control, but was not as attractive as the raspberry extract. To our knowledge, this is the first report of a behaviorally and antennally active blend of host fruit volatiles attractive to D. suzukii, offering promising opportunities for the development of improved monitoring and behaviourally based management tools.





P22: Proceedings of the Royal Society of London B. 2015 Feb; 282: 20143018, DOI: 10.1098/rspb.2014.3018

Loss of Drosophila pheromone reverses its role in sexual communication in Drosophila suzukii

Dekker T., Mansourian S., Revadi S., Ramasamy S., Lebreton S., Becher P.G., Angeli S., Rota-Stabelli O. and Anfora G.

Department of Plant Protection Biology, Swedish University of Agricultural Sciences, Alnarp, Sweden

The Drosophila pheromone cis-11-octadecenyl acetate (cVA) is used as pheromone throughout the melanogaster group and fulfils a primary role in sexual and social behaviours. Here, we found that Drosophila suzukii, an invasive pest that oviposits in undamaged ripe fruit, does not produce cVA. In fact, its production site, the ejaculatory bulb, is atrophied. Despite loss of cVA production, its receptor, Or67d, and cognate sensillum, T1, which are essential in cVA-mediated behaviours, were fully functional. However, T1 expression was dramatically reduced in D. suzukii, and the corresponding antennal lobe glomerulus, DA1, minute. Behavioural responses to cVA depend on the input balance of Or67d neurons (driving cVA-mediated behaviours) and Or65a neurons (inhibiting cVA-mediated behaviours). Accordingly, the shifted input balance in D. suzukii has reversed cVA's role in sexual behaviour: perfuming D. suzukii males with Drosophila melanogaster equivalents of cVA strongly reduced mating rates. cVA has thus evolved from a generic sex pheromone to a heterospecific signal that disrupts mating in D. suzukii, a saltational shift, mediated through offsetting the input balance that is highly conserved in congeneric species. This study underlines that dramatic changes in a species' sensory preference can result from rather ‘simple’ numerical shifts in underlying neural circuits.




P21: Physiological Entomology. 2015 Jan; 40(1): 54–64, DOI: 10.1111/phen.12088

Olfactory responses of Drosophila suzukii females to host plant volatiles

Revadi S., Vitagliano S., Rossi Stacconi M.V., Ramasamy S., Mansurian S., Carlin S., Vrhovsek U., Becher P.G., Mazzoni V., Rota-Stabelli O., Angeli S., Dekker T., Anfora G.

Fondazione Edmund Mach, San Michele all'Adige, Italy

Drosophila suzukii Matsumura, an endemic pest in southeast Asia, has invaded Europe and the U.S.A. Unlike most of its closely related sibling species, the serrated ovipositor of D. suzukii permits ovipositing in undamaged fresh fruits. In the present study, volatiles are identified from host plants that are potentially involved in D. suzukii host recognition and oviposition behaviour. It is shown that mated females are attracted to volatiles emitted from intact fruits. The antennally-active suite of compounds released from the fresh fruits is identified by gas chromatography coupled with electroantennographic detection, as well as gas chromatography-mass spectrometry. In olfactometer bioassays, mated females are significantly attracted to an electroantennographically active volatile, isoamyl acetate, when tested at 10 µg of synthetic compound in a rubber septa, which has a release rate comparable to that of fresh fruits. In addition, a genomic survey shows that D. suzukii not only possesses the full repertoire of genes encoding odorant receptors activated by isoamyl acetate in D. melanogaster, but also that one of the genes, OR67a, is represented by five duplicated copies. These results indicate that D. suzukii uses olfactory cues to select oviposition sites. The identification of volatiles emitted by host fruits that attract D. suzukii may aid in the development of a selective and efficient synthetic lure for monitoring this pest. As a close relative of Drosophila melanogaster, D. suzukii provides a unique opportunity for understanding the physiological mechanisms involved in the shift of this species from use of rotten to ripe fruits for oviposition.





P20: BMC Genomics. 2014 Dec; 15(1): 1141, DOI:10.1186/1471-2164-15-1141

Tissue-specific transcriptomics, chromosomal localization, and phylogeny of chemosensory and odorant binding proteins from the red flour beetle Tribolium castaneum reveal subgroup specificities for olfaction or more general functions

Dippel S., Oberhofer G., Kahnt J., Gerischer L., Opitz L., Schachtner J., Stanke M., Schuetz S., Wimmer E. A. and Angeli S.

Department of Developmental Biology, University of Goettingen, Germany

Background: Chemoreception is based on the senses of smell and taste that are crucial for animals to find new food sources, shelter, and mates. The initial step in olfaction involves the translocation of odorants from the periphery through the aqueous lymph of the olfactory sensilla to the odorant receptors most likely by chemosensory proteins (CSPs) or odorant binding proteins (OBPs).
Results: To better understand the roles of CSPs and OBPs in a coleopteran pest species, the red flour beetle Tribolium castaneum (Coleoptera, Tenebrionidae), we performed transcriptome analyses of male and female antennae, heads, mouthparts, legs, and bodies, which revealed that all 20 CSPs and 49 of the 50 previously annotated OBPs are transcribed. Only six of the 20 CSP are significantly transcriptionally enriched in the main chemosensory tissues (antenna and/or mouthparts), whereas of the OBPs all eight members of the antenna binding proteins II (ABPII) subgroup, 18 of the 20 classic OBP subgroup, the C + OBP, and only five of the 21 C-OBPs show increased chemosensory tissue expression. By MALDI-TOF-TOF MS protein fingerprinting, we confirmed three CSPs, four ABPIIs, three classic OBPs, and four C-OBPs in the antennae.
Conclusions: Most of the classic OBPs and all ABPIIs are likely involved in chemoreception. A few are also present in other tissues such as odoriferous glands and testes and may be involved in release or transfer of chemical signals. The majority of the CSPs as well as the C-OBPs are not enriched in antennae or mouthparts, suggesting a more general role in the transport of hydrophobic molecules.




P19: Bulletin of Insectology. 2014 Jan; 67(1): 21-30

Olfactory cues of mahogany trees to female Hypsipyla robusta

Abraham J., Opuni-Frimpong E., Weissbecker B., Schuetz S. and Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

The mahogany shoot borer, Hypsipyla robusta (Moore) (Lepidoptera Pyralidae), is a serious pest insect in the tropical forests of Africa, Asia and Australia. This insect causes multiple branching of young shoots in indigenous mahogany plantations. Gravid insects are attracted to oviposition sites by volatile organic compounds (VOCs) released by their hosts. Therefore, in this study, we aimed to (i) identify and characterise the VOCs released by the shoots of Entandrophragma and Khaya mahogany and (ii) to determine the electrophysiologically active VOCs which could influence the olfactory response of H. robusta. Volatile samples were collected from shoots of Entandrophragma angolense (Welwitsch) de Candolle, Entandrophragma utile (Dawe et Sprague) Sprague, Khaya anthotheca (Welwitsch) de Candolle and Khaya ivorensis Chevalier by closed-loop-stripping-analysis. The VOCs were identified by gas-chromatography mass-spectrometry (GC-MS) and characterised by comparing their retention times with those of authentic standards. For the first time, 29 VOCs were characterised as typical of the four mahogany species studied. The VOCs included alcohols, aldehydes, alkanes, alkenes, esters, ketones, monoterpenes, alcohol sesquiterpenes and sesquiterpenes. The majority were esters (10) and sesquiterpenes (8). GC-MS/electroantennographic detection experiments revealed antennal responses of the female moth to (Z)-β-ocimene, (Z)-3-hexen-1-yl acetate, hexan-1-ol, nonanal, (Z)-3-hexen-1-yl butanoate, 2-ethyl hexan-1-ol, decanal, β-caryophyllene, (Z)-3-hexen-1-yl hexanoate and germacrene D. Dose-response experiments with three of the compounds revealed antennal responses at concentrations of 10-7 to 10-2. We therefore suggest that these compounds are olfactory cues of female H. robusta and could be used in behaviour-based control of H. robusta.




P18: Journal of Food Science and Technology. 2014 Sep; 51(9): 2062–2069

Effect of extraction and concentration processes on properties of longan syrup

Surin S., Thakeow P., Seesuriyachan P., Angeli S. and Phimolsiripol, Y.

Faculty of Agro-Industry, Chiang Mai University, Thailand

Longan (Dimocarpus longan Lour.) syrup is a novel liquid sweetener produced from longan, one of the traditional and economic fruits in the Northern of Thailand. In this research, the effect of extraction and concentration processes on properties of longan syrup was investigated. There were two extraction methods (juice extractor and hydraulic press) and three concentration methods (direct heating, steam heating and vacuum evaporation). Results overall showed that the extraction method had no significant (p≥0.05) effect on longan syrup properties, while concentration resulted in the quality changes of longan syrup. Concentration using direct heating of longan juice caused reduction of sucrose content, and longan syrup dark in color. The headspace volatile compounds of longan syrup were sampled using direct headspace technique and further characterized using gas chromatography-mass spectrometry. The identified volatile compounds could be divided into two groups of aroma characteristics which were (1) floral aroma: 3-methybutyl acetate, (β)-ocimene and 2-phenylethyl alcohol and (2) caramel aroma: butyraldehyde, furfural and benzaldehyde. 2-Phenylethyl alcohol, contributing to floral odor, was retained using vacuum evaporation as a concentration method. Result revealed that the optimal concentration process for longan syrup production was vacuum evaporation, providing the highest floral volatile and lowest caramel volatile. Sensory tests confirmed that longan flavor of the syrup produced from the vacuum evaporation process had significantly higher hedonic scores than other processes.




P17: Italus Hortus. 2013 Sep; 20(3): 3-17

Ecology and management of exotic Drosophila suzukii

Vitagliano S., Grassi A., Anfora G. and Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

This paper reviews the taxonomy, distribution, basic biology, behaviour, ecology and management of exotic D. suzukii (Diptera: Drosophilidae) with particular emphasis to the Italian situation. D. suzukii is native to the South East Asia and was found for the first time outside its native habitat in the Hawaiian Islands in 1980, then in California and in Spain in 2008. Over the last 5 years the species has been found in many States of North America and several European countries. In Italy D. suzukii was identified for the first time in Trentino-Alto Adige in 2009, with subsequent detections in Piedmont, Valle d'Aosta, Lombardy, Veneto, Emilia-Romagna, Tuscany, Liguria, Marche, Campania and recently in Sicily. The species has caused extensive damage in all Regions where it became established and has demonstrated a very rapid expansion. In the Trento Province, for instance, the damage to small berry fruits production has been estimated in 3.000.000 € in 2010. D. suzukii is a polyphagous insect but the most damages are recorded mainly on fruits of blueberry, strawberry, raspberry, cherry, and on some varieties of grapes. In natural ecosystems D. suzukii reproduces on blackberry, elder, buckthorn, etc. Unlike other Drosophilids, D. suzukii shows the peculiar characteristic of females being able to lay their eggs inside ripening fruits, starting from veraison and preferring fruits with a thin epicarp. Females have a well-developed saw-like ovipositor, which can penetrate beneath the skin of host fruits. How males and females find each other is not yet well understood. Currently, the species has established in many European countries and North America. Control strategies adopted so far include preventive measures, the use of specific insecticides and trapping of adults. Several biocontrol agents, such as parasitoids of larvae and pupae and natural predators are under investigation. These studies could help to apply classical biological control strategies, by introducing D. suzukii natural enemies, coming from the pest’s native habitat. At present, management techniques referring to an ecological control, as the “push-pull” strategy, are not developed. Early investigations are currently focused on the possibility to reduce pest populations through the exploitation of the pest association with endosymbionts; moreover, studies aiming to investigate D. suzukii host fruits relationships are also in progress, to identify the most attractive volatile compounds, to be used in the preparation of highly selective and attractive baits for D. suzukii.




P16: Chiang Mai University Journal of Natural Sciences. 2012 Apr; 11(1): 181-191

Physical, chemical and sensory characterization of the Thai-crispy pork rind ‘Kaeb Moo’

Sriwattana S., Utama-ang N., Thakeow P., Senapa J., Phimolsiripol Y., Surawang S., Pongsirikul I. and Angeli S.

Faculty of Agro-Industry, Chiang Mai University, Thailand

Crispy pork rind, called ‘Kaeb Moo’ in Thai, is a typical and very popular food in the northern region of Thailand. It is made from deep frying pork skin, previously cut in slices. There are basically two different types of Kaeb Moo, the first one consisting only of the skin layer and the second one where subcutaneous fat is also present. Kaeb Moo may undergo rapid change of quality, as rancidity, after it has been processed. However, little has been done so far for quality assessments and certification of the Thai crispy pork rind. In this research, investigations on chemical, physical and sensorial aspects of Kaeb Moo were performed in order to determine the quality parameters of this product. Samples were purchased from well-known local producers of Chiang Mai province, or prepared in-house. The average hardness of each sample ranged from 15.0 to 40.0 kgf, while moisture and fat contents were 0.3 - 2.3 and 20.0 - 36.5%, respectively. The degrees of lipid oxidation were in the range of 0.10 - 2.57 μg malondialdehyde g-1. Volatile compounds were investigated by headspace-solid phase microextraction technique and GC-MS. The following compounds were found: propanal, hexanal, heptanal, 2-heptanone, 2-pentyl furan, heptane, octane, and 4-methyl octane. Descriptive analysis profiling was used to express the sensorial attributes and 18 important attributes of Kaeb Moo were described by 12 trained panelists. Finally, consumer acceptance test (n = 400) using 9-point hedonic scale was carried out in respect to colour, odour, taste, crispness, and overall-liking.




P15: Naturwissenschaften. 2010 Apr;  97(6): 595-599 Issue Front Page

Eco-physiology of dorsal versus ventral cuticle in flattened sawfly larvae

Boevé J.-L. and Angeli S.

Department of Entomology, Royal Belgian Institute of Natural Sciences of Bruxelles, Belgium

Platycampus larvae are highly cryptic leaf feeders characterised by a dorso-ventrally flattened body, the dorsal integument resembling a shield. Dorsal and ventral cuticles from Platycampus luridiventris were compared by histology and gel electrophoresis. By Azan-staining, a red and a blue layer were distinguished in the dorsal cuticle, while the ventral cuticle showed one, almost uniform blue layer, as in both cuticles of control species. The two cuticles from P. luridiventris had similar amounts and sodium dodecyl sulphate-polyacrylamide gel electrophoresis profiles of soluble proteins, but not insoluble proteins. One insoluble protein (MW≈41 kDa) was visible as a large band in the ventral cuticle only. It is likely that this protein renders the cuticle elastic, and that the dorsal, red layer is the exocuticle, mainly composed of insoluble proteins. We discuss eco-physiological implications of the exocuticle in insects. Further, data from the literature indicate that the defence strategy in P. luridiventris larvae relies on being visually cryptic towards avian predators and tactically cryptic towards arthropod predators and parasitoids. Crypsis in both senses is favoured by the shield effect, itself based on an abnormally thick dorsal exocuticle. Although the larvae are external feeders, they may be considered as hidden from an ecological perspective.




P14: Agricultural and Forest Entomology. 2009 Oct; 11(4): 359–375, review paper

Ecology and management of exotic and endemic Anoplophora glabripennis (Coleoptera: Cerambycidae)

Hu J., Angeli S., Schuetz S., Luo Y. and Hajek A.E. 

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

1 The Asian longhorned beetle is native to China and Korea, and was found for the first time outside its native habitat in the U.S.A. in 1996, with subsequent detections being made in Canada and several European countries.
2 We review the taxonomy, distribution, basic biology, behaviour, ecology and management of endemic and exotic Anoplophora glabripennis, including information that is available in the extensive Chinese literature.
3 This species has caused massive mortality of Populus species in China and models have demonstrated that it could become established in many locations worldwide.
4 Anoplophora glabripennis is polyphagous but prefers Acer, Salix and Populus, section Aigeiros.
5 Although A. glabripennis adults do not disperse far when surrounded by host trees, they have the potential to fly more than 2000 m in a season.
6 Volatile organic compounds from preferred host trees are attractive to A. glabripennis and this attraction is heightened by drought stress. Males and females orientate to a volatile released by female A. glabripennis and males attempt to copulate after contacting a sex pheromone on the female cuticle.
7 At present, A. glabripennis is being (or has been) eradicated from areas where it has been introduced. After detection, extensive surveys are conducted and, if breeding populations are detected, at the very least, infested trees are removed and destroyed. Close attention is paid to imported solid wood packaging material to prevent new introductions.
8  Standard practice to control A. glabripennis in China is to spray insecticides in tree canopies. In North America, largely as a preventative measure, systemic insecticides are injected into trees. Entomopathogenic fungi have been developed for the control of A. glabripennis, and entomopathogenic nematodes, coleopteran and hymenopteran parasitoids and predatory woodpeckers have been investigated as biocontrol agents.
9  Ecological control of A. glabripennis in China involves planting mixtures of preferred and nonpreferred tree species, and this practice can successfully prevent outbreaks.





P13: Nature. 2008 Apr; 452(7190): 949-55

The genome of the model beetle and pest Tribolium castaneum

..., Robertson H.M., Angeli S., Forêt S., ...(Tribolium Genome Sequencing Consortium)

Human Genome Sequencing Center, Baylor College of Medicine, USA

Tribolium castaneum is a member of the most species-rich eukaryotic order, a powerful model organism for the study of generalized insect development, and an important pest of stored agricultural products. We describe its genome sequence here. This omnivorous beetle has evolved the ability to interact with a diverse chemical environment, as shown by large expansions in odorant and gustatory receptors, as well as P450 and other detoxification enzymes. Development in Tribolium is more representative of other insects than is Drosophila, a fact reflected in gene content and function. For example, Tribolium has retained more ancestral genes involved in cell-cell communication than Drosophila, some being expressed in the growth zone crucial for axial elongation in short-germ development. Systemic RNA interference in T. castaneum functions differently from that in Caenorhabditis elegans, but nevertheless offers similar power for the elucidation of gene function and identification of targets for selective insect control.

PMID: 18362917 [PubMed]




P12: Chem. Senses 2008 Apr; 33(4): 379-87

Antennal and behavioral responses of Cis boleti to fungal odor of Trametes gibbosa

Thakeow P., Angeli S., Weissbecker B. and Schuetz S.

Institute of Forest Zoology and Forest Conservation, University of Goettingen, Germany

Cis boleti (Coleoptera: Ciidae) preferentially colonizes fungi from the genus Trametes that are known as important wood decomposers. The aim of our research was to investigate if C. boleti uses the chemical volatile composition of its fungal host, Trametes gibbosa, as a key attraction factor. Therefore, the T. gibbosa fruiting body volatiles were analysed by using gas chromatography-mass spectrometry, with parallel electroantennographic detection (GC-MS/EAD) using adults of C. boleti. Furthermore, we examined the behavioral responses of C. boleti to the T. gibbosa volatile compounds. The dominant component of the T. gibbosa fruiting body bouquet was 1-octen-3-ol. Other volatiles, like the aldehydes hexanal, nonanal, and (E,E)-2,4-decadienal and the terpene alpha-bisabolol, were present in minor quantities. 1-Octen-3-ol was released with a ratio of the (R)- and (S)-enantiomers of 93:7, respectively. Electroantennography (EAG) employing C. boleti antennae yielded consistently dominant responses to 1-octen-3-ol. GC-EAD and EAG responses to pure standard compounds showed that C. boleti also perceived other host fungal volatiles. A highly significant attraction to 1-octen-3-ol was observed in behavioral tests. Female beetles were significantly attracted to the (S)-(+)- enantiomer at 10 times lower doses than male beetles. Our finding is the first direct proof that ciid beetles use 1-octen-3-ol as a key cue for host finding.

PMID: 18283043 [PubMed]




P11: Pak. J. Biol Sci., 2008 May 1; 11(9): 1246-51

Use of CLSA and SPME-headspace techniques followed by GC-MS analysis to extract and identify the floral odorants

Shonouda M., Angeli S., Schuetz S. and Vidal S.

AgroEntomology Section, Department of Crop Sciences, University of Goettingen, Germany

Flowers of Ziziphus spina christi are known to be attractive for parasitoids and predators. In Y-tube olfactometer experiments, the dried flowers attracted significantly (p < 0.001) the female parasitoids Aphelinus abdominalis. The flower volatile compounds were analyzed to understand which compounds could be specifically responsible for this attractiveness. The volatile compounds of Ziziphus flowers were extracted by closed-loop-stripping-analysis (CLSA) and also by solid phase microextraction (SPME) followed by gas chromatography-mass spectrometry (GC-MS) analysis. The main chemical classes of the volatile compounds are aldehydes, monoterpene-alcohols, ketones and hydrocarbons. Flower extract and some specific compounds will be further tested for their responsiveness to predators and parasitoids in behavioural and electrophysiological experiments.

PMID: 18819533 [PubMed]




P10: Biochemistry, 2006 Sep 5; 45(35): 10606-13

Solution structure of a chemosensory protein from the desert locust Schistocerca gregaria

Tomaselli S., Crescenzi O., Sanfelice D., Ab E., Wechselberger R., Angeli S., Scaloni A., Boelens R., Tancredi T., Pelosi P. and Picone D.

Department of Chemistry, University of Naples, Italy

Chemical stimuli, generally constituted by small volatile organic molecules, are extremely important for the survival of different insect species. In the course of evolution, insects have developed very sophisticated biochemical systems for the binding and the delivery of specific semiochemicals to their cognate membrane-bound receptors. Chemosensory proteins (CSPs) are a class of small soluble proteins present at high concentration in insect chemosensory organs; they are supposed to be involved in carrying the chemical messages from the environment to the chemosensory receptors. In this paper, we report on the solution structure of CSPsg4, a chemosensory protein from the desert locust Schistocerca gregaria, which is expressed in the antennae and other chemosensory organs. The 3D NMR structure revealed an overall fold consisting of six alpha-helices, spanning residues 13-18, 20-31, 40-54, 62-78, 80-90, and 97-103, connected by loops which in some cases show dihedral angles typical of beta-turns. As in the only other chemosensory protein whose structure has been solved so far, namely, CSP from the moth Mamestra brassicae, four helices are arranged to form a V-shaped motif; another helix runs across the two V's, and the last one is packed against the external face. Analysis of the tertiary structure evidenced multiple hydrophobic cavities which could be involved in ligand binding. In fact, incubation of the protein with a natural ligand, namely, oleamide, produced substantial changes to the NMR spectra, suggesting extensive conformational transitions upon ligand binding.

PMID: 16939212 [PubMed]




P9: Journal of Nanobiotechnology, 2004 Oct; 2:10

Surface structure, model and mechanism of an insect integument adapted to be damaged easily

Boevé J.-L., Ducarme V., Mer tens T., Bouillard P., Angeli S.

Department of Entomology, Royal Belgian Institute of Natural Sciences of Bruxelles, Belgium

BACKGROUND: Several sawfly larvae of the Tenthredinidae (Hymenoptera) are called easy bleeders because their whole body integument, except the head capsule, disrupts very easily at a given spot, under a slight mechanical stress at this spot. The exuding haemolymph droplet acts as a feeding deterrent towards invertebrate predators. The present study aimed to describe the cuticle surface, to consider it from a mechanistic point of view, and to discuss potential consequences of the integument surface in the predator-prey relationships. RESULTS: The integument surface of sawfly larvae was investigated by light microscopy (LM) and scanning electron microscopy (SEM) which revealed that the cuticle of easy bleeders was densely covered by what we call "spider-like" microstructures. Such microstructures were not detected in non-easy bleeders. A model by finite elements of the cuticle layer was developed to get an insight into the potential function of the microstructures during easy bleeding. Cuticle parameters (i.e., size of the microstructures and thickness of the epi- versus procuticle) were measured on integument sections and used in the model. A shear force applied on the modelled cuticle surface led to higher stress values when microstructures were present, as compared to a plan surface. Furthermore, by measuring the diameter of a water droplet deposited on sawfly larvae, the integument of several sawfly species was determined as hydrophobic (e.g., more than Teflon®), which was related to the sawfly larvae's ability to bleed easily. CONCLUSION: Easy bleeders show spider-like microstructures on their cuticle surface. It is suggested that these microstructures may facilitate integument disruption as well as render the integument hydrophobic. This latter property would allow the exuding haemolymph to be maintained as a droplet at the integument surface.

PMID: 15461785 [PubMed]




P8: FEBS Letters, 2004 Aug; 13, 572 (1-3), 3-7

Plant stress proteins of the thaumatin-like family discovered in animals

Brandazza A., Angeli S., Tegoni M., Cambillau C. and Pelosi P.

Dipartimento di Chimica e Biotecnologie Agrarie, University of Pisa, Italy

Thaumatin-like proteins (TLPs) are polypeptides of about 200 residues synthesized by plants in response to fungal infection. In addition to the exceptionally strong sweet taste exhibited by some members, they are also reported to be endowed with endo-beta-1,3-glucanase activity and alpha-amylase inhibiting properties. However, the detailed mechanism of their antifungal action is not completely understood. So far, TLPs have only been described in plants, with several members of the family expressed in the same species. Here, for the first time in animals, we report the identification of two genes encoding members of the thaumatin-like proteins family in the desert locust Schistocerca gregaria and show their expression in different parts of the body. Southern blot and Western blot experiments revealed the presence of orthologous genes and their expression products in the related species Locusta migratoria. A search through the available genomes yielded similar sequences in the nematode Caenorhabditis but not in Drosophila and other insects. A three-dimensional model of S. gregaria TLP suggests a glucanase function. As in plants, TLPs could play a defense role in insects against pathogens.

PMID: 15304314 [PubMed]




P7: Insect Molecular Biology, 2003 Apr; 12 (2), 125–134

Chemosensory proteins of Locusta migratoria

Ban L., Scaloni A., Brandazza A., Angeli S., Zhang L., Yan Y. and Pelosi P.

Dipartimento di Chimica e Biotecnologie Agrarie, University of Pisa, Italy 

Two different classes of chemosensory proteins (CSPs) in Locusta migratoria have been identified on the basis of the molecular cloning of a series of different cDNAs from the antennae of this insect. Several CSP isoforms have been purified and biochemically characterized from antennal and wing extracts, some of them corresponding to expression products predicted for the identified cDNAs. In wings, the nature of the main endogenous ligand binding to these proteins was determined as oleoamide by a gas chromatography–mass spectrometric approach. One of these isoforms has been expressed in a bacterial system with high yield and used in a fluorescent binding assay. Competitive binding experiments have indicated the presence of long-chain compounds among the best ligands.

PMID: 12653934 [PubMed]



P6: Arthropod Structure and Development, 2002 Feb; 30 (3), 195-205

Ultrastructural characterization of antennal sensilla and immunocytochemical localization of a chemosensory protein in Carausius morosus Brünner (Phasmida: Phasmatidae)

Monteforti G., Angeli S., Petacchi R. and Minnocci A.

Sant'Anna School of Advanced Studies of Pisa, Italy 

The aim of this work was to investigate the olfactory system of the walking stick insect, Carausius morosus. Morphological, ultrastructural and immunocytochemical studies of adult female antennae were conducted by scanning and transmission electron microscopy. Extensive cross-section series were made through the last antennal segment to define the cuticular apparatus, wall pore distribution and the number of innervating receptor neurons of each sensillum type. Single-walled wall pore sensilla occur in three subtypes: (i) with 27 or 28 branched receptor neurons, (ii) with two branched neurons and (iii) with one or two unbranched neurons, respectively. Double-walled wall pore sensilla were found in two subtypes with spoke channels, one with four unbranched neurons, the other with two unbranched neurons. One terminal pore sensillum was found, showing two cavities within the hair and being innervated by six sensory cells. Immunocytochemical experiments were performed to show the localization of a 19kDa soluble protein found in the chemosensory organs of C. morosus. This protein shows an amino acid sequence homologous to the family of chemosensory proteins (CSP). The polyclonal antibody raised against the purified protein (CSP-cmA) showed, for the first time in CSPs, a strong labeling in olfactory sensilla, specifically in the sensillum lymph surrounding the dendritic branches of SW-WP sensilla and in the uninnervated lumen between the two concentric walls of DW-WP type 1 sensilla.

PMID: 18088955 [PubMed]



P5: European Journal of Biochemistry (now FEBS Journal), 2001 Sep; 268 (17), 4794-4801

Bacterial expression and conformational analysis of a chemosensory protein from Schistocerca gregaria

Picone D., Crescenzi O., Angeli S., Marchese S., Brandazza A., Ferrara L., Pelosi P. and Scaloni A.

Dipartimento di Chimica, University of Naples, Italy.

Chemosensory proteins (CSPs) are a class of small, soluble proteins present at high concentrations in chemosensory organs of different insect species. Several pieces of evidence suggest their involvement in carrying chemical messages from the environment to chemosensory receptors. However, a structural description of the mechanism of delivery has not been reported. In order to provide the first detailed conformational characterization of these molecules, we cloned a specific isoform (CSP-sg4) from Schistocerca gregaria and expressed it in Escherichia coli
PMID: 11532016 [PubMed]


 
P4: Insect Biochemistry and Molecular Biology, 2000 Nov; 30(11), 1091-1098

Soluble proteins from chemosensory organs of Eurycantha calcarata (Insects, Phasmatodea)

Marchese S., Angeli S., Andolfo A., Scaloni A., Brandazza A., Mazza M., Picimbon J., Leal W.S. and Pelosi P.

Dipartimento di Chimica e Biotecnologie Agrarie, University of Pisa, Italy

Three related nucleotide sequences, encoding mature proteins of 108-113 amino acids, have been obtained from antennal cDNA of the Phasmid Eurycantha calcarata. Among these, one is also expressed in the tarsi as demonstrated by N-terminal sequence and mass spectrometric analyses of protein samples isolated from both organs. PCR experiments performed with specific primers, showed that this species is also expressed in the mouth organs and in the cuticle, while the other two are antennal specific. All three isoforms are similar to Drosophila OS-D and other proteins reported in several insect orders, but one of them is significantly different from the other two. The best conserved elements are the N-terminal region and the four cysteine residues. Accurate ESMS measurements indicated that all cysteines are involved in two disulphide bonds and ruled out the occurrence of additional post-translational modifications. Polyclonal antibodies, raised against the purified protein, did not react with proteins of the same class expressed in another Phasmid species, Carausius morosus, and in the orthopteran Schistocerca gregaria, nor did antibodies against these proteins recognise those of E. calcarata.

PMID: 10989296 [PubMed]


 
P3: Archives of Insect Biochemistry and Physiology, 2000 Jul; 44 (3), 120-129

Purification and molecular cloning of chemosensory proteins from Bombyx mori

Picimbon J.F., Dietrich K., Angeli S., Scaloni A., Krieger J., Breer H. and Pelosi P.

Institute for Physiology, University of Hohenheim, Germany.

Soluble low molecular weight acidic proteins are suspected to transport stimulus molecules to the sensory neurons within insect sensilla. From the antennae of Bombyx mori, we have purified and sequenced a protein (BmorCSP1) bearing sequence similarity to a class of soluble chemosensory proteins recently discovered in several orders of insects. Based on its N-terminal sequence, the cDNA encoding this protein has been amplified and cloned. Differential screening of a B. mori antennal cDNA library led to the identification of a second gene encoding a related protein (BmorCSP2), sharing 35-40% identity to BmorCSP1 and chemosensory proteins from other species. The predicted secondary structures of moth's, chemosensory proteins comprise alpha-helical foldings at conserved positions and a reduced hydrophobicity with respect to this novel family of chemosensory proteins.

PMID: 10897093 [PubMed]


 
P2: Biochemical and Biophysical Research Communicatins, 1999 Dec; 266(2), 386-391

Structural analysis and disulfide-bridge pairing of two odorant-binding proteins from Bombyx mori

Scaloni A., Monti M., Angeli S. and Pelosi P.

Centro Internazionale Servizi di Spettrometria di Massa-IABBAM, National Research Council, Italy

Pheromone-binding protein (PBP) and general odorant-binding proteins (GOBPs) were purified from the antennae of Bombyx mori and structurally characterised. The amino acid sequence of GOBP-2 has been corrected. The disulphide arrangements of PBP and GOBP-2 have been determined by a combined mass spectrometric/Edman degradation approach. The same cysteine pairings, Cys19-Cys54, Cys50-Cys108, and Cys97-Cys117, were found in both proteins, suggesting that such patterns occur commonly throughout this family of molecules. This arrangement of disulphide bonds indicates that the three-dimensional structure of insect OBPs is defined by three loops, rich in helical content, which can vary in size and charge distribution from one protein to another.

PMID: 10600513 [PubMed]


 
P1: European Journal of Biochemistry (now FEBS Journal), 1999 Jun; 262(3), 745-54 Issue Front Page

Purification, structural characterization, cloning and immunocytochemical localization of chemoreception proteins from Schistocerca gregaria

Angeli S., Ceron F., Scaloni A., Monti M., Monteforti G., Minnocci A., Petacchi R. and Pelosi P.

Sant'Anna School of Advanced Studies of Pisa, Italy

Soluble low-molecular-mass protein isoforms were purified from chemosensory organs (antennae, tarsi and labrum) of the desert locust Schistocerca gregaria. Five genes encoding proteins of this group were amplified by PCR from cDNAs of tarsi and sequenced. Their expression products are polypeptide chains of 109 amino acids showing 40-50% sequence identity with putative olfactory proteins from Drosophila melanogaster and Cactoblastis cactorum. Direct structural investigation on isoforms purified from chemosensory organs revealed the presence in the expression products of two of the genes cloned. Two additional protein isoforms were detected and their molecular structure exhaustively characterized. MS analysis of all isoforms demonstrated that the four cysteine residues conserved in the polypeptide chain were involved in disulfide bridges (Cys29-Cys38 and Cys57-Cys60) and indicated the absence of any additional post-translational modifications. Immunocytochemistry experiments, performed with rabbit antiserum raised against the protein isoform mixture, showed selective labelling of the outer lymph in contact sensilla of tarsi, maxillary palps and antennae. Other types of sensilla were not labelled, nor were the cuticle and dendrites of the sensory cells. No binding of radioactively labelled glucose or bicarbonate was detected, in disagreement with the hypothesis that this class of proteins is involved in the CO2-sensing cascade. Our experimental data suggest that the proteins described here could be involved in contact chemoreception in Orthoptera.

PMID: 10411636 [PubMed]



 

Oral Communications, Posters and Conference Proceedings

 

A49: International Graduate Research Conference (iGRC 2014), Chiang Mai (Thailand), 12 December 2014

Changes of physical, chemical, and sensory properties of crispy pork rind ‘Kaeb Moo’ during storage and its shelf life

1Kitpot T., 1Thakeow P., 1Sriwattana S., 2Angeli S.

1 Faculty of Agro-Industry, Chiang Mai University, Thailand
2 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

In northern region of Thailand, crispy pork rind, called ‘Kaeb Moo’, is very well known food. It is made by deep frying sliced cut pork skin. After processing, its physical, chemical, and sensory properties may be changed due to several factors. In this research, investigations on chemical, physical and sensorial properties of Kaeb Moo during storage in polypropylene bags at 25±1ºC were performed in order to determine their quality changes and shelf life. Samples were prepared in-house (controlled method) and purchased from local producers in Chiang Mai province, Thailand. According to the results, at the end of shelf life (purchase intent < 50%), the properties of Kaeb Moo samples were as follow: moisture content > 5%, hardness > 12 kgf, crispness (in terms of linear distance) < 40 kg.s, the sensory liking scores for overall, odor, crispness and overall taste were lower than 4.5, 5, 4 and 4.5 respectively (9-point hedonic scale). Kaeb Moo shelf lives for in-house and commercial samples were 4 and 2 weeks, respectively.



A48: International workshop on Molecular Basis of Fire Blight, Bolzano (Italy), 15 October 2014

Volatile organic compounds produced by fire blight infected apple flowers discourage honeybees visits

1Spinelli F., 1Cellini A., 1Buriani G., 1Donati I., 2Giacomuzzi V., 3Rodriguez-Estrada M.T., 2Fernandez Ferrari M.C., 3Savioli S., 1Costa G., 4Vanneste J. 4Angeli S.

1 Department of Agricultural Sciences, University of Bologna, Italy
2 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
3 Department of Agricultural and Food Sciences, University of Bologna, Italy
4 Plant abd Food Research, Waikato Mail Centre, New Zealand

Honeybees can spread Erwinia amylovora from infected to healthy flowers. In this study, we aimed to determine whether honeybees show a preference for healthy or infected flowers. For this reason, visits on infested and non-infested apple flowers during blooming were monitored by several methods in controlled conditions. The first method consisted in the direct count of visiting bees per time unit. For the second method, a pollen insert was loaded with an epiphytic bacterium (Pantoea agglomerans strain P10c) and placed at the hive exit. Thus, bees carried P10c to the flowers they visited. Presence of this bacterium on flowers was determined by q-PCR and direct isolation. The last method was based on the quantification of E. amylovora cells on the pollen loads collected by bees, which is correlated to the percentage of infected flowers visited. The three complementary methods provided similar results showing that bees visited more often healthy flowers. This behaviour was independent from previous bee training on either healthy or infected flowers.
Flower morphology, nectar composition, pollen production and volatile organic compounds (VOCs) emission were investigated as factors affecting bee preferences. VOCs collected by closed-loop-stripping-analysis (CLSA) and solid phase microextraction (SPME) were analysed by gas chromatography-mass spectrometry (GC-MS). No difference in pollen production, nectar composition and flowers colours was observed. Therefore, this first evidence of a VOCs-based ecological interaction among host plant, pathogen and pollinator suggests that VOCs play a critical role in the discrimination between healthy and E. amylovora-infected flowers by honeybees.




A47: XXIV Italian National Congress of Entomology, Orosei (Italy), 9-13 June 2014 (spoken presentation)

Drosophila suzukii non utilizza il cis-vaccenil acetato come feromone di aggregazione, diversamente da altre specie del genere Drosophila

1Anfora G., 2Dekker T., 2Mansourian S., 1,2Revadi S., 1Ramasamy S., 2Lebreton S., 2Becher P., 1Rota-Stabelli O., 3 Angeli S.

1 Chemical Ecology Group, Fondazione Edmund Mach of San Michele all’Adige, Italy
2 Unit of Chemical Ecology, Swedish University of Agricultural Sciences, Alnarp, Sweden
3 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

Background: Drosophila suzukii is an exotic species native to the Southeast Asia. It was found for the first time outside its native habitat in the Hawaiian Islands in 1980, then in California, Spain and Italy in 2008. Over the last 5 years the species has been spread in many States of North America and several European countries, causing extensive damage across the countries where it became established, demonstrating a very rapid expansion. D. suzukii occupies a unique niche among Drosophila species, since females possess hard ovipositors which enables them to lay eggs in fresh ripening fruits. This peculiar morphological adaptation, present only in other three Asiatic species (D. subpulchrella, D. pulchrella, and D. biarmipes), allowed the D. suzukii to occupy a new feeding niche, promoting divergence from the other similar species.
Results: In this paper we documented for the first time that D. suzukii has achieved a reproductive isolation from other Drosophila species, thanks to a saltational shift in its pheromone communication. We found that the Drosophila aggregation-pheromone, cis-11-vaccenyl acetate (cVA), is not produced by D. suzukii. Accordingly, we dissected the ejaculatory bulb of this species and found this organ to be much reduced in shape, compared to the model species D. melanogaster. Despite loss of cVA production, the cVA olfactory receptor was found to be expressed and fully functional in D. suzukii, although the number of antennal sensilla bearing Or67d and the shape of the corresponding DA1 glomerulus were much reduced. Behavioral assays showed that cVA strongly reduced mating behavior in D. suzukii, opposite than in D. melanogaster.
Conclusion: We concluded that D. suzukii has evolved a new divergent ecological function for cVA, driven by the shift in oviposition preference. In particular, cVA lost its function as a male-produced aggregation-pheromone and acquired a deterrent effect, allowing, therefore, D. suzukii to recognise places already infested with other drosophilids.



A46: 5th Annual Meeting of the European PhD Network in Insect Science, Orosei (Italy), 8-9 June 2014

Control of the Grapevine Moth Lobesia botrana through the genetic engineering manipulation of the host plant's volatiles

1, 2Salvagnin U., 2Anfora G., 2Malnoy M., 2Martens S., 1Angeli S.

1 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
2 Research and Innovation Centre, Fondazione Edmund Mach of S. Michele all’Adige, Italy

The European grapevine moth Lobesia botrana is one of the key pests of grape. The caterpillar feeding activity leads to a direct damage on reproductive plant tissues (flower buds and berries) but also to an indirect damage by promoting secondary infections of microorganisms. Current control systems are based on the use of insecticides or on mating disruption: while the first is not environmentally friendly, the second is not particularly suitable for non-delimited areas, or areas where pest population is high. Here we explore the possibility to develop a new control strategy of L. botrana by interfering with the female host-finding and egg-laying behaviors, which are mostly mediated by the host-plant-volatiles (kairomones). Recent wind-tunnel studies have shown that a blend of 3 specific grapevine plant terpenoids, namely (E)-beta-caryophyllene, (E)- beta-farnesene and (E)-4,8-dimethyl-1,3,7-nonatriene, elicited attraction comparable to that of the complete plant odor profile. Moreover, the specific ratio among these compounds showed to be crucial, since the subtraction or the percentage variation of any of the three chemicals resulted into an almost complete inhibition of the attractive blend. The same chemicals gave also promising result when tested in field conditions, but their direct application is not a strategy economically feasible due to their extremely high cost. A promising alternative approach may consist in modifying the releasing ratio of these compounds by modifying the metabolic pathways of the plant. To achieve this goal we are at present working on cv. Chardonnay, by creating new genetically stable lines. Preliminary data will be presented at the workshop.




A45: API ORGANICA 2014, Bologna (Italy), 3-7 March 2014

Evaluation of a fungal application to increase varroa controlling by Metarhizium anisopliae

1Mair S., 1Fernandez Ferrari M.C., 2MalagniniV., 2Fontana P., 1Angeli S.

1 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
2 Centre for Technology Transfer, FEM-IASMA of San Michele all’Adige, Italy

The ectoparasitic mite species Varroa destructor is one of the most serious threat to European honey bees, as it is considered the main cause of the die-off of huge numbers of colonies in most countries where European Apis mellifera is present. Varroa can be defeated with synthetic chemicals, but residues in honey bee products and arisen resistances to chemicals make it necessary to find new control methods. A possible new approach could be use of biological control methods, as for instance the entomo-acaropathogenic fungus Metarhizium anisopliae. This fungus is alredy prpose as a biological control agent of several arthropods, e.g. of ticks and beetles. In a hive the use of entomo-acaropathogenic fungi can be limited by interior physical conditions of the hive, considering the relatively high temperatures of approximately 35°C and the low relative humidity inside a bee colony. In this in-field trial we evaluated if a special isolate of M. anisopliae var. anisopliae BIPESCO 5 is a possible biological control agent against V. destructor. 16 colonies were divided in 2 treatments (i.e. 'Metarhizium' group and control group) of eight replicates each. From 13 June until 3 July each colony of the 'Metarhizium' group was dusted weekly for 4 times with 10 g of conidia (concentration of 1010 CFU/g). After waiting 14 further days all the 16 colonies were split in 16 parental colonies with the queens but without brood and 16 queenless nucleus colonies containing the remaining brood. The parental broodless colonies were exposed to a follow-up oxalic acid treatment to assess the residual mite level. The queenless nucleus colonies were transferred in a new apiary to avoid robbing and were observed for further 24 days until all brood hatched. Then, they were also treated with oxalic acid. During the entire experiment live phoretic mites were sampled weekly with the powdered sugar method. Dead mites were count on mesh bottom board. Residual mite-fall was assessed until 2 weeks after the oxalic acid treatment. Colony strength and colony health status were also weekly monitored. Bee mortality was monitored by counting the dead bees in in specific under-baskets traps. Although not all data are statistically significant, we could monitor always lower mite levels in the 'Metarhizium' group than in the 'Control'. Pre-oxalic acid treatment mite-fall on nucleus colonies was significantly reduced in the colonies where the fungus was applied, compared with the control, which imply that there were less reproductive mites in the 'Metarhizium' at the moment of the hive split. Moreover, we proved that  M. anisopliae had no impact on colony strength and development. These results lead us to consider M. anisopliae var. anisopliae BIPESCO 5 a promising biological control agent against varroa.




A44: 4th Annual Meeting of the European PhD Network in Insect Science, Paluzza (Udine), 19-22 September 2013 (keynote talk)

Unravelling a new language of nature: insect-plant communication through volatile compounds

Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

During the last 400 million years of coevolution insects and plants have developed a fascinating language based on the releasing and perception of specific volatile compounds. For instance, a vast majority of plants rely on volatile compounds to attract pollinating insects. At the same time plants defend themselves  from herbivorous insects  by the releasing of specific volatile compounds. As recently discovered, plants can even inform their neighbouring plants of the presence of herbivorous insects on their branches, a phenomenon called “talking trees”. Moreover, plants can release other volatiles to call predators of their enemies, a phenomenon called “cry for help”. Insects, on the other hand, have perhaps the most sensitive and selective olfactory system and they strongly rely on it to recognise their conspecifics, their prey and their hosts. Decoding these new chemical languages, different for each insect species, have important implications also for modern agriculture, in a effort to develop effective new eco-friendly and substanable pest control strategies.




A43: 9th COLOSS Conference, Kiev (Ukraine), 27-28 September 2013

Imidacloprid treatments of apple orchards lead to residues and chronic toxicity in bee colonies

1Malagnini V., 1Fontana P., 2Nazzi F., 3Di Prisco G., 3Caprio E., 3Pennacchio F., 4Angeli S.

1 Centre for Technology Transfer, FEM-IASMA of San Michele all’Adige, Italy
2 Dipartimento di Scienze Agrarie e Ambientali, Università degli Studi di Udine, Italy
3 Dipartimento di Agraria, Università degli Studi di Napoli, Italy
4 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

The neonicotinoids insecticides clothianidin, thiamethoxam and imidacloprid have been found to pose a high risk to bee health and a two-years partial ban of these molecules has been issued by the European Commission, starting on December 2013. Since the introduction of neonicotinoids in 1991, these insecticides have been linked to the declining bee populations across the globe, registered especially in the northern Hemisphere. At present there is a growing body of evidence that neonicotinoids have a detrimental effect on several insect pollinators. The major concerns have regarded their use as seed treatments (particularly on corn, canola, sunflower and soybean) and the contaminated dust during planting. In 2008 and in 2011 large bee mortality was associated with contaminated dust during corn seed planting in Germany and in Indiana (USA. Direct intoxication of forager bees is likely related to consumption of contaminated nectar as well as to plant guttation of treated plants, which may cause direct kill of forager bees or a change of forager bee behaviour, such as homing failure and disorientation. Moreover, neonicotinoids may cause also intoxication inside the hive due to the transportation of contaminated pollen, which does not harm directly forager bees. The intoxication of bees via pollen translocation within the hive has been less investigated. For this reason we decided to determine whether neonicotinoids may affect honeybee vitality and colony performance due to contaminated pollen translocation. We sampled bees and bee products (pollen loads, honey, wax, bee bread and royal jelly) of hives located in apple orchards of Trentino region (Italy), in which imidacloprid treatments are usually done after apple flowering to control aphid populations. Hives were placed few weeks before apple flowering and samples were taken before and after insecticide applications on April 18, 2012 and May 18, 2012, respectively. At the end of field test hives were transferred to a different location, with subsequent record of vitality and colony consistence parameters, every two weeks till winter. Results showed that imidacloprid was present in pollen loads even before treatments (~15 ppb) and increased strongly after treatments (~66 ppb). A similar result was found in wax and honey, whereas beebread did not show a significant change. Royal jelly showed a slight contamination of imidacloprid 2 months after treatments, equal to ~0.3 ppb. Our results suggest that imidacloprid may play a chronic detrimental effect on colony vitality, even several weeks after the treatments.




A42: Symposium Internationale Entomofaunisticum Europa Centralis XXIII, Bolzano (Italy), 9-13 September 2013

Parasite-host interaction between Varroa destructor and Apis sp.

1Fernandez Ferrari M.C. 2Nazzi F., 1Angeli S.

1 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
2 Department of Agricultural and Environmental Sciences, University of Udine, Italy

The ectoparasitic honey bee mite, Varroa destructor, was originally affecting only the partially resistant Asian honeybee, Apis cerana, until a host shift happened to the European honeybee, Apis mellifera, in 1950s-1970s when colonies of A. mellifera were brought to Asia. During the last three decades this mite became present world-wide, heavily affecting honeybee populations, honey production and beekeeping in several countries around the world. Unfortunately, no permanent solution has been found, emerging this parasitic mite as the foremost problem for apiculture worldwide. In addition, research in the biology, behavior and life cycle of V. destructor has been almost solely conducted on the western honeybee. Nonetheless, a deeper understanding of the original host-parasite relationship would help to better understand the current host-parasite association. In this research two different aspects of the interaction between V. destructor and A. mellifera and between V. destructor and A. cerana are investigated. Firstly, we focus on the mechanisms involved in the Varroa mite dispersion, in particular on the phenomenon of robbing. During robbing a stress situation in the beehive due to fights between the individuals from different colonies takes place, and the mites seem to abandon they original hosts to subsequently infest robbing bees which will later transport them to their colony. The host-changing during robbing is a key point for the mite dispersion and may be mediated by chemicals compounds. Secondly, we aim to investigate the chemo-ecological interaction between Varroa mite and its original host A. cerana. Previous studies demonstrated that Varroa mite uses the honeybee epicuticular hydrocarbon to select the most suitable host stage to infest. However, studies on the epicuticular hydrocarbons profile of A. cerana have not been done yet. Therefore, we aim to characterize the epicuticular hydrocarbons pattern in the A. cerana and its role in Varroa mite orientation behavior.



A41: International Conference of Chemical Ecology 2013, Melbourne (Australia), 19-23 August 2013

Characterization of Apis cerana and Apis mellifera epicuticular hydrocarbons and their role in Varroa destructor orientation behavior

Fernandez Ferrari M. C. and Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy 
During last three decades the parasitic mite Varroa destructor has become present world-wide, heavily affecting honey bee populations, honey production and beekeeping. In contrast, its original host the Asian bee Apis cerana has coexisted with the mite since long, making it well adapted to the parasite. Previous studies demonstrated that Varroa mite uses the honeybee epi-cuticular hydrocarbon composition for a proper selection of the most suitable host stage to infest. During both phoretic and reproductive stages, Varroa mite discriminates between ages and tasks of the adult bees using host epi-cuticular hydrocarbons patterns, which enables it to choose the suitable host. However, studies on the epi-cuticular hydrocarbons profile of A. cerana and its role in Varroa mite orientation behavior has not been done yet. In this work, we aimed to characterize the epi-cuticular hydrocarbons pattern in the Asian honey bee Apis cerana and its role in Varroa mite behavior. Firstly, adult honey bees of both species were collected in Chiang Mai, Thailand where the Asian honey bee is a native inhabitant and the European honey bees are commercially reared. Subsequently, the epi-cuticular hydrocarbons were extracted and characterized by using a gas chromatography - mass spectrometry (GC-MS) analysis. The results show differences among the profiles of both species which may highlight the diverse ecological aspects between parasitization of A. mellifera and A. cerana.




A40: International Conference of Chemical Ecology 2013, Melbourne (Australia), 19-23 August 2013

Exploiting the scent of fruits to protect crops against Drosophila suzukii

1Abraham J., 2Rodriguez-Saona C., 3Zhang A., 1Angeli S.

1 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
2 Marucci Center for Blueberry Cranberry Research Extension, Rutgers University, USA
3 United States Department of Agriculture, Maryland, USA

Drosophila suzukii is a new invasive pest insect in Europe and North America causing an increasing damage to soft-skinned fruit farms. Blueberries, cherries, raspberries and strawberries are among the major fruits affected by this pest. Unlike most other Drosophila flies, D. suzukii attacks ripening fruits making it difficult to protect fruit crops with synthetic pesticides due to the closeness to harvesting time. Therefore, alternative behaviourally-based pest control strategies are critical. In order to develop attractive host-attractants for D. suzukii, we extracted juices from blueberry, cherry, raspberry and strawberry and tested their attractiveness to D. suzukii in laboratory olfactometer studies. The results showed that all of the fruit juices are attractive to D. suzukii; however those from raspberry and strawberry were most attractive. The headspace volatiles from these juices were also tested in GC-EAD experiments using both male and female D. suzukii antennae and strong electrophysiological activities were observed. Once these EAD active volatile compounds from raspberry and strawberry were identified and activity was conformed in field condition, they could be used as baits for mass trapping or attract-and-kill strategies to control D. suzukii infestation in soft-skinned fruit farms.



A39: International Conference of Chemical Ecology 2013, Melbourne (Australia), 19-23 August 2013

Melolontha melolontha: a root feeding pest in apple orchards

Abraham J., Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

The European cockchafer, Melolontha melolontha L., is a large scarab beetle whose larvae are serious pest in apple orchards. About 98% (egg, larval and pupal stages) of the life of M. melolontha is spent in the soil. During this period the larvae feeds and destroy the roots of their hosts. Although the adults feed on the leaves of Quercus spp., Acer spp., Carpinus spp., Fagus spp. and Prunus spp., the effect of their feeding on leaves is seldom dangerous to the host. The larvae are voracious pests that feed on the roots of many crops including potato, lettuce, strawberry, apple tree and even some forest trees. The effect of feeding on root could lead to the eventual death of the host. Using apples (M9) rootstocks, we investigated whether or not the feeding damage caused by M. melolontha on apple roots alter the release of volatile organic compounds and hence herbivore induced plant volatiles (HIPV) from the roots. We also investigated if such a damaged on the roots will cause a systematic release of HIPV on the leaves that could be priming neighbouring plants. Our investigation revealed an alteration in the constitutive volatile compounds profile of both the roots and leaves of apple plants that had their roots fed on by M. melolontha. Our results may contribute in understanding belowground insect-plant interaction and open a new way of biological control strategy of M. melolontha in apple orchards.



A38: 19th Australasian Plant Pathology Conference (APPS), Auckland, New Zealand, 25-28 November, 2013

Volatile organic compounds produced by fire blight infected apple flowers reduce honeybees visits

1Spinelli F., 1Cellini A., 1Buriani G., 2Donati I., 2Giacomuzzi V., 3Rodriguez-Estrada M.T., 3Savioli S., 1Costa G., 4Vanneste J., 4Angeli S.

1 Department of Agricultural Sciences, University of Bologna, Italy
2 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
3 Department of Food Science and Technology, University of Bologna, Italy
4 Plant and Food Research, Waikato Mail Centre, New Zealand

Honeybees have been demonstrated to vector Erwinia amylovora, the causal agent of fire blight, which is the most destructive disease of pome fruits. Since bees choose the flowers they visit based on by flower colour and shape, nectar composition, pollen production and volatile compounds (VOCs) emission, in the present study we characterized all these parameter in healthy and infected apple flowers. VOCS were collected by closed-loop-stripping-analysis (CLSA) and by solid phase microextraction (SPME) and analysed by gas chromatography-mass spectrometry (GC-MS). To determine whether honeybees show a preference for healthy or infected flowers, an experiment was performed in controlled conditions on flowering scions. To monitor bees visits on flowers direct counting, and other methods, developed in this study, were used. In details, a pollen insert, placed at the exit of the hive, was loaded with a lyophilized preparation of an epiphytic bacterium (Pantoea agglomerans strain P10c). Exiting the hives, bees carried P10c to the flowers they visited. Presence of this bacterium on flowers was determined by q-PCR and direct isolation. A complementary method for estimating bees preference was based on the quantification of E. amylovora cells on the pollen collected by bees. The population of E. amylovora on collected pollen is thought to be correlated to the percentage of infected flowers visited. The three complementary methods used to estimate bees preference provided similar results showing that bees visited more often healthy flowers. This behaviour was independent of whether bees had been previously exposed exclusively either healthy or infected flowers. No difference in pollen production, nectar composition and flowers colours was observed. Therefore, our results suggest that VOCs may play a critical role in determining which flower bees prefer to visit. This is the first evidence of a VOCs-based ecological interaction occurring between host plant, pathogen and pollinator. In addition, the results show that the role of bees in diffusing E. amylovora might need further studies to be fully clarified.




A37: Tropentag: Agricultural development within the rural-urban continuum. Stuttgart-Hohenheim, Germany, 17-19 September 2013

Feeding damage of Pandemis heparana induces the release of specific volatile compounds from apple plants

Giacomuzzi V., Abraham J., Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

Pandemis heparana Denis Schiffermüller (Lepidoptera, Tortricidae) is one of the most widespread tortricid leafrollers in European apple orchards and is considered a key pest of apple plants. It is widely distributed in central and north Europe as well as parts of Asia and North America. Larvae of P. heparana cause damages primarily on the foliage of its host plants, although they may damage fruits as well. The aim of the present study was to find out if mechanically-damaged and P. heparana-damaged apple plants are able to release specific volatile compounds in response to the two different damages, as an indirect defence mechanism. Herbivore-induced plant volatiles (HIPVs) are in fact known to play a critical role in tritrophic interactions. The volatile organic compounds (VOCs) released by the leaves of one-year-old apple seedlings were collected by closed-loop-stripping-analysis and characterised by gas-chromatography mass-spectrometry. Volatiles were collected for three subsequent days from undamaged, mechanically-damaged and insect-damaged seedlings in three replicates. The mechanical damage was caused on the first day of the experiment (single wounding event). In the case of insect damaged seedlings, 12 larvae were left on the leaves of each plant, feeding for three days. Twelve VOCs were characterised in the undamaged apple seedlings. They included (Z)-3-hexenyl acetate, nonanal, decanal, 2-ethylhexanol and 8 linear and branched hydrocarbons, ranging from C14 to C20. In case of mechanically-damaged apple seedlings, 6 more volatile compounds were found, namely acrolein diethyl acetal, (E)-4,8-dimethyl-1,3,7-nonatriene, (Z)-3-hexenyl butyrate, (Z)-3-hexenyl benzoate, indole and alpha-farnesene. In case of P. heparana-damaged seedlings, we were able to detect a total of 25 volatile compounds. Among these, 8 compounds were specifically induced, namely the terpenes (E)-beta-ocimene, beta-caryophyllene, germacrene D, linalool, calamenene and cadalene, and the benzenoids benzyl cyanide and methyl salicylate. Our experiments showed for the first time that apple plants strongly respond to insect damage in a specific manner. The volatile profile of P. heparana-damaged apple plants included several compounds that were not detected in either undamaged or mechanically-damaged plants. These HIPVs could be important for the development of new eco-friendly techniques of insect pest control in apple orchards.




A36: Conference “Future IPM in Europe”, Riva del Garda (Italy), 19-21 March 2013

Electrophysiological and behavioural responses of Drosophila suzukii to host plant volatiles

1Vitagliano S., 2Rossi Stacconi M.V., 2Revadi S., 1Angeli S., 2Mazzoni V., 2Carlin S., 2Vrhovsek U., 2Anfora G.

1 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
2 Chemical Ecology Group, Fondazione Edmund Mach of San Michele all’Adige, Italy

Drosophila suzukii is a highly polyphagous invasive pest endemic to South East Asia, which has recently invaded western countries. Its serrated ovipositor allows this fly to lay eggs on and damage unwounded ripening fruits, and for this reason it is considered a main threat to fruit production. D. suzukii presence in Europe is spreading rapidly and has now been reported in nine countries. The development of environmentally-safe control methods is urgent for a safeguard of the concerned fruit industry. The aim of this study was therefore to characterize and identify the volatiles of the D. suzukii host plants which influence its olfactory behaviour in order to set-up management strategies based on semiochemicals. The olfactory responses of the adult flies for the odour released by intact host fruits (raspberry, blackberry, cherry, blueberry and strawberry) in behavioural assays (Y-shaped glass olfactometer) have been evaluated. D. suzukii females were expected to choose between the test material (25 g of fresh fruits) and the control (holding the same amount of fruits wrapped in a trasparent plastic bag). It was shown that D. suzukii females are significantly attracted to the volatiles emitted from the 5 tested fruits. Volatile compounds emitted by the attractive host fruits have been extracted and identified (GC-MS), and their biological activity on D. suzukii females screened by means of electrophysiological analysis (GC-EAD). Electroantennographic (EAG) and behavioural assays (Y-shaped glass olfactometer) have been also carried out to test the biological activity of isoamyl acetate on D. suzukii mated females. This compound is the only VOC released from all the fruit species analyzed and able to elicit antennal responses in D. suzukii mated females. Analysis of the EAG responses to increasing doses of isoamyl acetate (from 0.1 pg/μl to 100 μg/μl) in hexane solutions showed that isoamyl acetate induced a dose-response relationship. It also showed significant attractiveness to D. suzukii females in Y-shaped olfactometer, when loaded in red rubber dispensers at the dosage of 10 µg. Environmentally friendly control strategies against D. suzukii could be potentially enhanced by using kairomones. The identification of the most behaviourally-active volatiles emitted by fruits host of D. suzukii might allow the development of more selective and powerful attractant lures that could be released at controlled rates from dispensers in strategies such as mass trapping and attract and kill.




A35: 24th International Congress of Entomology, Daegu, South Korea, 19-25 August 2012

Changes in apple plant volatiles in response to feeding damage of Pandemis heparana

Giacomuzzi V., Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

The volatile organic compounds (VOCs) emitted by the leaves of young apple seedlings of Golden Delicious were collected by close loop stripping analysis and characterized by the gas-chromatography mass-spectrometry. Volatile emissions were taken from undamaged, mechanically damaged and insect damaged seedlings. The insect damaged seedlings were previously infested with ten larvae (IV instar) of one of the major apple pests, namely the moth Pandemis heparana (Lepidoptera: Tortricidae). Volatiles were collected for three subsequent days. In the headspace of undamaged plants 12 volatile compounds were indentified, among which the green-leaf-volatiles (Z)-3-hexenyl acetate and ethyl-hexanol, together with the aldehydes nonanal and decanal. In case of mechanically damaged leaves 18 compounds were detected, where (Z)-3-hexenyl acetate represented the highest peak. Some compounds, as acrolein diethyl acetal, (E)-4,8-dimethyl-1,3,7-nonatriene, (Z)-3-hexenyl butyrate, (Z)-3-hexenyl benzoate, indole and α-farnesene were found in the headspace of mechanically damaged plants but not in healthy plants. Six hours after damage (Z)-3-hexenyl acetate concentrations strongly decreased. In the headspace of seedlings damaged by P. heparana 26 volatile compounds were characterized. Among them, some VOCs were uniquely induced, as the monoterpene (E)-β-ocimene, the terpene alcohol linalool, the sesquiterpenes β-caryophyllene and germacrene D, the sesquiterpenoids calamenene and cadalene, the benzenoids benzyl cyanide and methyl-salicylate. Our results clearly showed, for the first time, that apple trees strongly changed their volatile emission profile as a result of a specific, herbivore-induced response to P. heparana damage.




A34: 24th International Congress of Entomology, Daegu, South Korea, 19-25 August 2012

Volatile organic compounds of teak and behavioral responses of termites to teak volatiles

1Thakeow P., 2Angeli S.

1Division of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Thailand
2Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

Termites are the most destructive insect pests of wood. However, in Thailand teak (Tectona grandis) has been a popular constructing material for centuries because it is well-known termite-resistant timber. In this research, we aimed to investigate the behavior of termites towards teak extract. Teak sawdust was extracted using dichloromethane and methanol as solvents. Then volatile organic compounds (VOCs) released directly from sawdust and from the extract were analysed using SPME-GC-MS. In addition, the chemical compositions of the extract were analyzed by LC-MS. VOCs released by teak sawdust belong to several chemical groups, i.e. alcohols, aldehydes, ketones, hydrocarbons, esters, and terpenes. There were 12 VOCs detected in headspace of teak sawdust and 33 VOCs identified in the extract. These compounds were, for example, 3-methyl-2-butenal, octane, nonane, α-pinene, β-pinene, 6-methyl-5-hepten-2-one, decane, hexyl acetate, limonene, undecane, and nonanal. Interestingly, some VOCs detected in sawdust headspace were not found in the extract. 2-Hydroxymethyl anthraquinone was found in the extract. This compound is a biologically active substance. The behavioral responses of termites to the characterized teak VOCs will be further described and discussed.




A33: 24th International Congress of Entomology, Daegu, South Korea, 19-25 August 2012

How are odorant binding proteins involved in olfaction of Tribolium castaneum?

1Murugan K., 2Dippel S., 3Angeli S., 4Pelosi P., 5Schachtner J., 2Wimmer E., 1Schuetz S.

1 Institute of Forest Zoology and Forest Conservation, University of Goettingen, Germany
2 Department of Developmental Biology, University of Goettingen, Germany
3 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
4 Dip. Chimica e Biotecnologie Agrarie, University of Pisa, Italy
5 MPI for Terrestrial Microbiology, Marburg, Germany

The red flour beetle (Tribolium castaneum) is accessible to transgenic approaches as directed gene expression, powerful reverse genetics based on systemic RNA interference and a recently published full genome sequence. Moreover, its longevity offers a suitable system to address olfaction from the odor recognition and discrimination at the periphery to the analysis of the plasticity of the central olfactory pathway.
Reverse genetic, electrophysiological and chemo-ecological approaches are combined to study the correlation of odorants to odorant binding proteins (OBP). The biological function of OBPs is still largely unknown, despite their necessity for olfaction. Especially the interaction of OBPs with odors is of key interest and is evaluated at the molecular and at the electrophysiological level




A32: "Research Path: Innovation for Creative Economy and Sustainability" Symposium, Chiang Mai (Thailand) 25-26 November 2010

Analysis of volatile organic compounds released from teak sawdust

1Thakeow P., 1Sutthaphakti K., 1Sakdatorn V., 2Angeli S.

1 Division of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Thailand
2 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

Teak (Techtona grandis) is commonly used as building and furniture materials in the north of Thailand since it is beautiful and unique in structure. In addition, it provides good properties of fungal inhibition and insect repellence. Therefore, in this research, it was aimed to identified volatile organic compounds (VOCs) released from teak sawdust and its extract. The analysis was carried out using solid phase microextraction (SPME) together with gas chromatography-mass spectrometry (GC-MS). Two types of SPME fibers used were Carboxen/Polydimethylsiloxane and Divinylbenzene/Carboxen/Polydimethylsiloxane. It was found that VOCs of teak sawdust belonged to many groups of chemicals, i.e., alcohol, aldehyde, ketone, hydrocarbon, ester, and terpenes. There were 32 VOCs identified in teak extract, while 12 volatiles were identified in headspace of teak sawdust. Furthermore, none of VOCs identified in teak sawdust headspace were detected in the extract. One quinone, 2-hydroxymethylanthraquinone, was found in teak extract.




A31: VIII National Postharvest Technology Conference, Chiang Mai (Thailand), 1-3 September 2010, plenary lecture

Learning insect olfaction to build novel highly sensitive olfactory-based biosensors

Angeli S.

Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy

XXX



 
A30: VIII National Postharvest Technology Conference, Chiang Mai (Thailand), 1-3 September 2010

Antennal responses of rice weevils to volatile organic compounds released by jasmine paddy rice

1Thakeow P., 2Angeli S.

1 Department of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Thailand
2 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy.

The most famous and favoured variety of Thai rice is the aromatic jasmine rice, Khao Dok Mali 105 (KDML 105). It possesses unique flavour, good appearance, and good texture. In each year there has been loss of rice during storage due to the rice pest Sitophilus oryzae (Coleoptera: Curculionidae). Therefore, there have been several attempts aiming to prevent and control the rice weevil infestations. For example, stored rice is often treated with low toxic organophosphorous insecticides and fumigant treatments. Nowadays, for insect control, semiochemicals often plays an important role in modem agriculture. Insects use volatile organic compounds (VOCs) for orientation in mating, host finding, and food source orientation. These chemicals are generally not dangerous to human health, and are used as a valid alternative to reduce the economic losses of pest insects. Therefore, in this research, we examined volatiles released from KDML105 paddy rice using four sampling techniques, namely, (i) solid phase micro extraction, (ii) close loop stripping analysis, (iii) thermal desorption system, and (iv) direct headspace analysis. The collected volatiles were identified using gas chromatography-mass spectrometry. The VOCs detected from headspace of paddy rice belongs to different chemical groups, but most of them are aldehydes. Afterwards, the VOCs were tested with S. oryzae dissected antennae using a gas chromatograph-mass spectrometer coupled with electroantennographic detector (GC-MS/EAD). It was found that insect antennae responded consistently to hexanal. This finding could lead to an alternative and environmental friendly pest control technique for the rice weevil S. oryzae.



 
A29: XXIII IUFRO World Congress, "Forests for the Future: Sustaining Society and the Environment, Seoul (Republic of Korea), 23-28 August 2010

Olfactory cues of female Hypsipyla robusta (Moore) (Lepidoptera: Pyralidae) to mahoganies of the genera, Entandrophragma and Khaya

1Abraham J., 2Angeli S., 3Schuetz S., 3Weissbecker B. and 1Opuni-Frimpong E.

1 Forest Research Institute of Ghana, Kumasi, Ghana
2 Faculty of Science and Technology, Free University of Bozen-Bolzano, Italy
3 Institute of Forest Zoology and Forest Conservation, University of Goettingen, Germany

The mahogany shoot borer, Hypsipyla robusta (Moore) (Lepidoptera: Pyralidae) is a serious pest insect attacking and damaging indigenous mahogany plantations. It is believed that H. robusta relies on olfaction and gravid females are attracted by volatile compounds of mahogany trees. This research was conducted to determine which volatile compounds influence the attack of mahogany trees in the genera, Entandrophragma and Khaya. Volatile samples were collected from shoots of Entandrophragma angolense, Entandrophragma utile, Khaya anthotheca and Khaya ivorensis in field and laboratory sampling in Ghana by Closed Loop Stripping Analysis (CLSA). Gas-chromatography mass-spectrometry electroantennographic detection and electroantennogram experiments were performed with the volatile samples. The results revealed significant responses of the female moth antennae to 1-hexanol, 2-ethyl-1-hexanol, beta-caryophyllene, cis-ocimene, cis-3-hexenyl acetate, cis-3-hexenyl butyrate, cis-3-hexenyl hexanoate, decanal, germacrene D, naphthalene and nonanal. Dose-response curves of electroantennogram responses for these compounds showed that female H. robusta are able to perceive 1-hexanol and nonanal at very low concentrations. We therefore propose that these compounds may serve as long-range attractants for female H. robusta to localized mahogany host trees and may be used as trap baits.



 
A28: XXII Italian National Congress of Entomology, Ancona (Italy), 15-18 June 2009

Studio delle interazioni nella codifica di composti volatili in Cydia pomonella (L.) mediante la superposizione di stimoli olfattivi

1Vitagliano S., 2Angeli S., 2Thakeow P., 1De Cristofaro A.

1 Dipartimento di Scienze Animali, Vegetali e dell’Ambiente, Università del Molise, Italy
2 Institute of Forest Zoology and Forest Conservation, University of Goettingen, Germany

Cydia pomonella (L.) (Lepidoptera: Tortricidae) è fitofago di primaria importanza per melo, pero e noce. (E, Z) - 2,4-etil-decadienoato, un estere estratto da pere mature, esercita un’elevata attività attrattiva sul fitofago. La possibilità di utilizzo di questo composto volatile per il monitoraggio degli adulti di entrambi i sessi, o come mezzo ausiliario nel controllo delle larve, potrebbe giocare un ruolo determinante nella gestione delle infestazioni di C. pomonella. Studi recenti hanno focalizzato l’attenzione sull’effetto combinato del principale componente del feromone sessuale di C. pomonella, il (E,E) - 8,10-dodecadien-1-olo o codlemone, ed il (E,Z) - 2,4-etil-decadienoato, nella prospettiva di migliorare l’efficienza delle trappole per il monitoraggio. Nel presente lavoro è stato utilizzato un elettroantennografo portatile, che applica la tecnica della superposizione, per lo studio delle interazioni esistenti fra la percezione del codlemone, del 2,4-etil-decadienoato e di altri composti volatili nelle antenne di C. pomonella. Il codlemone è stato utilizzato come odore di fondo, mentre altri composti organici volatili quali l’esenil-acetato, l’1-octen-3-olo, l’octanale, l’esanolo, il cariofillene, il linalolo, il farnesene e il (Z)-3-esen-1-olo, venigano saggiati in superposizione a diverse concentrazioni in paraffina. Comparando la risposta delle antenne di adulti di C. pomonella al solo odore di fondo e ai soli composti volatili con la risposta agli odori sovrapposti è stato possibile verificare l’esistenza di un’interazione nella percezione di alcuni di questi composti. Infatti, in alcuni casi si è osservato che le risposte in superposizione hanno ampiezza minore della somma delle risposte ai singoli stimoli. Ciò è imputabile alla presenza di recettori olfattivi comuni per le due sostanze, confermando quanto riportato in precedenti lavori dove è stato ipotizzato che la codifica olfattiva del codlemone e del 2,4-etil-decadienoato sia mediata, almeno in parte, da neuroni olfattivi che esprimono gli stessi recettori olfattivi. In futuro un utilizzo più esteso della tecnica per superposizione potrà contribuire a quantificare in maniera dettagliata le interazioni esistenti nella codifica olfattiva di diversi composti volatili della pianta ospite e dei componenti feromonici di C. pomonella.




A27: Entomologentagung DGaaE (=German Society for General and Applied Entomology), Göttingen (Germany), 16-19 March 2009

Attractive defence compounds and repellent host odours: unexpected behaviour of Bolitophagus reticulatus (Coleoptera: Tenebrionidae)

Holighaus G., Blome R., Angeli S.

Institute of Forest Zoology and Forest Conservation, University of Goettingen, Germany

The black tinder fungus beetle Bolitophagus reticulatus is a model organism to study landscape fragmentation effects on deadwood insects. This beetle feeds all life stages exclusively on fruiting bodies of the bracket fungus, Fomes fomentarius. Although B. reticulatus is a long-living organism and a good flyer, genetic isolation occurs in fragmented landscapes. Here, we investigated the chemoecology of the beetle to elucidate the function of some volatile organic compounds (VOCs) in terms of insect behaviour, feeding and reproduction. VOCs of F. fomentarius fruiting bodies at different degree of colonisation as well as the ones of abdominal defensive glands were analysed by gas chromatography (GC-MS). Selected VOCs were tested in a dual choice walking bioassay.
1-Octen-3-ol showed high level in young fruiting bodies of F. fomentarius, contrary to old, colonised fruiting bodies. Abdominal glands contain defensive compounds as methyl- and ethyl-benzoquinone. Moreover, we found m-cresol, which was never described in Tenebrionidae. The choice tests showed a strong repellence of 1-octen-3-ol, whereas a significant attraction to m-cresol was recorded. 1-Octen-3-ol has been previously characterised as an antifeedant against slugs. B. reticulatus avoids young fruiting bodies where 1-octen-3-ol level is comparably high. Therefore, we suggest that here 1-octen-3-ol plays a similar role as in the case of slugs. In a previous research, considerable aggregations of beetles within single fruiting bodies of F. fomentarius were found. The m-cresol of the abdominal glands may work as an aggregation pheromone, either for feeding or overwintering strategies. Further experimental research will be required to determin whether 1-octen-3-ol has a direct toxicity or characterises the fruiting body suitability. Moreover, field experiments could demonstrate the efficacy of m-cresol as aggregation pheromone.



 
A26: Entomologentagung DGaaE (=German Society for General and Applied Entomology), Göttingen (Germany), 16-19 March 2009

Response of the rice weevil Sitophilus oryzae L. to volatile compounds of jasmine rice KDML105

1Thakeow P., 2Angeli S.,3Vearasilp S., 2Schuetz S.

1 Department of Product Development Technology, Faculty of Agro-Industry, Chiang Mai University, Thailand
2 Department of Forest Zoology and Forest Conservation, University of Goettingen, Germany
3 Department of Seed Technology, Faculty of Agriculture, Chiang Mai University, Thailand

The rice weevil Sitophilus oryzae L. (Coleoptera: Curculionidae) is one of the most destructive pest insects in stored products. Rice weevil infests the seeds of rice, maize, sorghum, wheat, barley, and other cereals. In Thailand this insect is a severe pest species on rice, a very important agricultural product of the country. Therefore, we have started a study on the semiochemical communication of the rice weevil which could lead to develop an alternative approach of integrated pest management of this species. In this experiment, the jasmine rice KaoDawkMali105 (shortly called KDML105) was used. This rice variety is the most famous and most exported rice of Thailand. The volatile organic compounds (VOCs) of brown KDML105 were sampled using solid phase microextraction technique (SPME). Afterwards, the VOCs were further characterized using gas chromatography-mass spectrometry (GC-MS). The odor perception of the rice weevil was recorded using gas chromatography-mass spectrometry/electroantennographic detection (GC-MS/EAD) and electroantennography (EAG). Broad chemical classes of VOCs were detected in brown KDML105 rice: acetone, hexanal, 3-carene, 2-pentyl furan, limonene, octan-3-one, o-cymene, 1-octen-3-ol, 2-ethyl hexan-1-ol, camphor, N-ethylbenzenamine, and naphthalene. The results of GC-MS/EAD and EAG will be further described.



 
A25: XXII International Socity of Chemical Ecology Annual Meeting (XXII ISCE), Barcelona (Spain), 15-19 July 2006

Epicuticular hydrocarbons of Leptinotarsa decemlineata (Say): a sexual dimorphism

Angeli S., Thakeow P., Weissbecker B. and Schuetz S.

Institute of Forest Zoology and Forest Conservation, University of Goettingen, Germany

Insect epicuticular hydrocarbons play a key role as odorants in several species. During last years they have been found to be involved in chemoreception processes such as nest recognition of Apis mellifera, sexual pheromones in several Diptera, and the aggregation phenomenon of the desert locust Schistocerca gregaria.
In the present study we characterise the epicuticular composition of the Colorado Potato Beetle, Leptinotarsa decemlineata. Despite this insect is considered as one of the most dangerous pest species in agriculture, so far no sexual pheromone has been reported. In a previous work we identified a new volatile amino-aromatic compound from the elytra of males and females. Here we focus our attention on the pattern of hydrocarbon extracted from the cuticle of male and female elytra in order to characterize a possible sexual communication. In a previous research a sex-dependent composition of cuticular hydrocarbons of L. decemlineata has been already described but the methodologies we adopted and the results differ substantially from the reported ones. We extracted cuticular hydrocarbons from the elytra of single animals in different life stage, e.g. freshly emerged, mating and ovipositing females. We analyzed the heptane extracts by the mean of GC-MS using a specific temperature program reaching 310°C. The chromatograms were interpreted with NIST Standard Reference Database, and in comparison with standards chemicals. The results confirmed that there is no n-alkanes in the epicuticular hydrocarbon mixture of L. decemlineata, but -contrary of what previously reported- females did not show a higher quantity of hydrocarbons with more than 34 carbons atoms. In our experiments males showed a simpler mixture of hydrocarbons, where hydrocarbons with higher molecular weight are actually predominant in comparison with females. Moreover, three hydrocarbons are exclusively or highly more abundant in females. These three compounds appeared in the first half of the chromatogram, therefore with a relatively low molecular weight. The same data were also analyzed by using principal component analysis (PCA) Pirouette® software (Infometrix). A PCA scores plot showed a clear separation between male and female hydrocarbons.



 
A24: XVII Congress European Chemoreception Research Organization (XVII ECRO), Granada (Spain), 4-8 September 2006

Volatile organic compounds of Thai aroma rice

1,2Thakeow P., 1Angeli S., 2Ripon S., 3Simapaisan P., 2Thanapornpoonpong S., 1Schuetz S. (1)

1 Institute of Forest Zoology and Forest Conservation, University of Goettingen, Germany
2 Postharvest Technology Institute, Chiang Mai University, Thailand
3 Deptartment of Product Development, Faculty of Agro-Industry, Chiang Mai University, Thailand

Aroma rice, e.g. Basmati and Jasmine rice, is very popular among rice consumers in South and South-East Asia and is becoming famous in USA and Europe. Thailand is one of the major rice exporters; rice produced from Thailand possesses peculiar properties as aroma, appearance, and texture. One outstanding property of Thai rice, known as “Jasmine rice”, is its fragrance. The characteristic flavour of this rice is principally contributed by 2-acetyl-1-pyrroline. There are many varieties of aroma rice produce in Thailand, among which Khao Dawk Mali 105 (KDLM105) variety is the most famous one.
In this experiment, we investigated volatile organic compounds (VOC) of Thai rice (Oryza sativa) by using five varieties: KDLM105, RD15, PTN1, HSP and CNT1. All of them were planted in the experimental field in 2005. The first four varieties are aroma rice, the last one is a rice variety of high yield and good grain. The Jasmine rice bought from the retail store was also used. VOC released to the head space from dry stored and moistured-heated rice were sampled using solid phase microextraction (SPME). In order to optimise the device suitability, three different fibers, Carboxen/PDMS, Carbowax/DVB and PDMS/DVB, were chosen. The resulting compounds were analysed using GC-MS. In parallel, sensory evaluation of rice samples was carried out focussing on odour perception of the panel considering the parameters “variety” and “ageing”. The majority of VOC identified as highly abundant were aldhydes. Hexanal, considered as an off odour, was detected even in recently harvested rice.




A23: XVII Congress European Chemoreception Research Organization (XVII ECRO), Granada (Spain), 4-8 September 2006

Assessment of fungivorous insect antennae as biosensors for detecting wood rotting fungi

Thakeow P., Angeli S., Weissbecker B. and Schuetz S.

Institute for Forst Zoology and Forest Conservation, University of Goettingen, Germany

Trametes versicolor, Gloeophyllum trabeum and Poria placenta are known as wood destructive fungi, causing high economic losses in construction wood and wood composite products. To evaluate the quality of wood as raw-material for the production of high engineering property products, a reliable and sensitive detection of wood rotting fungi is needed. A rapid and non-destructive method for the evaluation of fungal infestation can focus on volatile organic compounds (VOC) released by fungi.
Beech wood (Fagus sylvatica) was inoculated either with G. trabeum, P. placenta or T. versicolor and incubated at 22°C for one week prior to sampling of VOC. Volatiles released to the head space were collected using solid phase microextraction (SPME), 85 µm Carboxen/PDMS StableFlex fiber type, and were analysed by GC-MS. Each fungus growing on beech released a specific pattern of VOC. The detected VOC can be categorised into two broad groups, aliphatic C5-C8 compounds and isoprenoids. Typical fungal odour compounds like 1-octen-3-ol and 3-octanone were produced by all three fungi. Two monoterpenes, alpha-pinene and 3-carene were found. However, dominant components with respect to abundance were sesquiterpenes. Sesquiterpene patterns were characteristic for each species. Moreover, 6-protoilludene was specifically produced by G. trabeum in high amounts. Alpha- and beta-barbatene were typical and dominant VOC of T. versicolor.
Cis boleti, an insect typically feeding on fruiting bodies of wood rotting fungi like T. versicolor was used for electroantennographic recordings of fungal volatiles. On the basis of these measurements the feasibility of a biosensor for the detection of wood rotting fungi was assessed.




A22: Proc. of the IX European Symposium on Insect Taste and Olfaction (IX ESITO), Villasimius (CA, Italy), 24-30 September 2005

Purification and first characterisation of soluble proteins involved in odorant recognition of Colorado potato beetle

Angeli S. and Schuetz S.

Institute for Forest Zoology and Forest Conservation, University of Goettingen, Germany

Odorant Binding Proteins (OBP) and Chemo-Sensory Proteins (CSP) are two classes of soluble globular proteins secreted in a very high concentration in the neuron-bathing fluid of insect chemosensory sensilla. In the last ten years, members of both classes were discovered and fully characterized in several insects mainly belonging to the Orders of Lepidoptera, Hymenoptera and Diptera. Despite some members of both classes are recently fully characterized in terms of three-dimensional  structure, binding activity and histological localization, a full explanation of their specific role in the sensillar lymph is still missing. However, several evidence addresses to an important function in the early coding process of odorant and taste compounds during the olfactory perception of insects. These proteins may also be a useful tool in developing artificial biomimetic chemosensors, since all members characterized so far have a high stability, no post-translational modification and can be easily expressed as recombinant proteins in a full functional form.
Therefore, we decided to investigate the chemosensory perception of Colorado potato beetle (Leptionotarsa decemlineata (Say)), where this type of protein had not been discovered. Extracts of body parts were obtained from males and females of our lab population and analyzed by SDS and NATIVE-PAGE. Protein profile of chemosensory organs, like mouthpart, antennae and tarsi, did not show any specific band in SDS condition, but a peculiar weak band specific for these extract became visible when the extracts were run in their native state.  Therefore, a mass-rearing of males and females were performed in order to obtain about 2000 antennae for each sex and to reach a full purification of the target proteins. A combination of gel-filtration and ion-exchange chromatography allowed the purification of a protein of an apparent molecular weight of 12 kDa and a low isoelectric point. A Western blot experiment with the polyclonal antibody raised against the CSP-Sg4 was performed in order to check if this protein belongs to the CSP or OBP family. No reaction of the polyclonal antibody was observed against our purified protein. A further purification was achieved by HPLC, and the isolated peak was subjected to Edman N-terminal degradation. The aminoacid sequence will be used to design a specific degenerated primer in order to clone the full sequence with RT-PCR and later to characterize the structure and the possible function of this new protein.




A21: XX Congresso Nazionale Italiano di Entomologia, Assisi (Italy), 12-18 June 2005

Caratterizzazione chimica, fisiologica e comportamentale di un nuovo feromone della dorifora della patata, Leptinotarsa decemlineata (Say)

Angeli S. and Schuetz S.

Institute for Forst Zoology and Forest Conservation, University of Goettingen, Germany

La dorifora della patata rappresenta l’insetto più dannoso nella coltura della patata e di altre Solanacee. Recentemente questa specie ha raggiunto una resistenza ad oltre 25 insetticidi comunemente impiegati per la protezione delle colture. Lo sviluppo di metodi di lotta alternativa si rende perciò necessario, in particolare in seguito al diffondersi sempre più marcato dell’agricoltura biologica dove questo insetto ritorna ad essere una vera calamità. Promettente potrebbe essere l’utilizzo di composti volatili ad azione feromonica. Diverse ricerche sono attualmente in corso per l’identificazione di questi composti, in particolare nel tentativo di determinare la struttura chimica del feromone sessuale che, avendo una potente azione attrattiva, permetterebbe di monitorare in maniera molto precisa la dinamica delle popolazioni in pieno campo.
Nel 2002 è stato isolato nella dorifora della patata il feromone di aggregazione, (S)-3,7-dimethyl-2-oxo-6-octene-1,3-diol, inaspettatamente emesso dai maschi (Dickens et al., 2002). Ricerche precedenti avevano inoltre messo in evidenza una diversa composizione di idrocarburi cuticolari fra maschi e femmine (Dubis et al., 1987). Ogni ricerca sulla natura chimica di un feromone sessuale di discreta volatilità non ha, fin’ora, portato a nessun risultato, sebbene prove comportamentali abbiano dimostrato che i maschi sono attratti da volatili emessi dalle femmine (Edwards and Seabrook, 1997).
In questa comunicazione gli autori riportano l’individuazione di un nuovo composto volatile, il 2-aminoacetofenone, identificato attraverso tecniche di GC/MS dagli estratti delle elitre di individui adulti sessualmente attivi di Leptinotarsa decemlineata. La secrezione di questo composto aromatico e di natura amminica risulta sorprendente, sebbene in altri coleotteri siano stati ritrovati altri feromoni di natura aromatica, ad esempio negli ultimi anni è stato identificato il 1,4-benzoquinone in Melolontha melolontha e il japonilure Popillia japonica. Il composto isolato da noi, 2-aminoacetofenone, potrebbe essere un buon candidato come feromone sessuale e per questo motivo sono state successivamente eseguite prove di elettroantennografia (EAG) su antenne di maschi e femmine e di orientazione in olfattometro. I risultati di EAG e di GC-MS-EAD confermano come questo composto venga percepito selettivamente dalle antenne in entrambi i sessi, a differenza dei composti simili 3- e 4-aminoacetofenone. Prove comportamentali in un olfattometro a 4 vie sono in corso e i risultati dell’analisi statistica verranno presentati in questa comunicazione.




A20: Entomologentagung Dresden 2005 DGaaE (=German Soc. for General and Applied Entomology), Dresden(Germany) 21-24 March 2005

Pheromones of Leptinotarsa decemlineata (Say): an integrated approach of electorophysiology, behaviour and biochemical study

Angeli S., Weissbecker B. and Scheutz S.

Institute for Forst Zoology and Forest Conservation, University of Goettingen, Germany

It has been documented that males of Leptinotarsa decemlineata (Coleoptera: Chrysomelidae) respond selectively to the wing extract of fertile females, suggesting that a sexual pheromone may be involved. In the past, several attempts have been made to elucidate the chemical structure of this compound. However, till now only an aggregation pheromone emitted by the males has been identified, while there is a complete lack regarding the female sexual pheromone. In the present communication, the authors would like to show a set of data regarding chemical communication of Colorado potato beetle using different approaches, like GC-MS analyses, antennal electrophysiology (EAG), behavioural assays and protein biochemistry. By the means of GC-MS we were able to identify a new volatile amino-aromatic compound from the forewing of adults, with females showing a higher concentration. We hypothesise that this compound may be a pheromone, in agreement with a previous research where only the methanol extract of female elytra stimulate male mating behaviour. By means of EAG we demonstrated that this odorant is clearly perceived by the antennae of both sexes and behavioural assays are in progress. We also planned to find out chemosensory proteins (CSP) and odorant binding proteins (OBP), which are involved in the first steps of insect olfactory transduction. An antennal specific protein has been recently extracted from both sexes and partially characterised. Similar proteins may occur also in pheromone emitting glands, since their ability of reversible bind specific odorants. Therefore, proteins were extracted from male and female forewings of L. decemlineata and partially characterised.




A19: 97. Jahresversammlung der Deutschen Zoologischen Gesellschaft, Rostock (Germany), 31 May-4 June 2004

Characterization of a cuticle protein of the sphinx moth Manduca sexta

Angeli S., Trenczek T.

Institute of Zoology, University of Giessen, Germany

Cuticular proteins of insects play an important role in defining mechanical and biological functions of their integument. These proteins may constitute more than 50% of the total cuticular weight, comprising several members such as arthropodin, sclerotin, and resilin. The different arrangement of the embedded chitin fibers, in association with the local protein secretion and the disposition of the layers, can change widely the mechanical properties of the integument in a way that confer optimal local plasticity and elasticity to the integument. In the present study, a protein of the larval endocuticular layer of Manduca sexta, is recognised by a monoclonal antibody (MS#77), previously raised against Manduca sexta haemocyte. In an effort to understand the specific property of this protein, a combined histological and biochemical study has been made. Firstly, immunohistological investigation of larval semi-thin transversal sections were performed with the original MS#77 hybridoma and a series of lectin labelling assays. An overlapping binding pattern to of the cuticular layers was found with the Vicia villosa lectin, which recognise preferentially alpha- or beta-linked terminal N-acetylgalactosamine, linked to serine or threonine in a glycopeptide. Western blot analyses were made after extraction of cuticular proteins with different buffers. A strong band of approximately 48 kDa appeared only when cuticle is extracted with high concentration of SDS and the yield increased when EDTA was added. Moreover, biotinylated V.v. lectin bind to the same protein, showing that the MS#77 antigen is likely to be a glycoprotein. Therefore, a large preparation of cuticular proteins were made under optimal buffer condition and the extracted proteins were subjected to gelfiltration, mono-Q and preparative electrophoresis purification, allowing us to fully purify the antigen. Finally, enzymatic and chemical deglycosylation techniques were performed. Results will be shown in the present communication.




A18: Innate Immunity Workshop: Bridging the gap between ecology and molecules, 6-9 May 2004

How to characterize the immune competence of an insect?

Trenczek T., Schmidtberg H. and Angeli S.

Institute of Zoology, University of Giessen, Germany

Research in insect immunity has developed an overwhelming amount of data sets and knowledge about antimicrobial peptides, diverse humoral factors, melanization responses, hemocyte types, phagocytosis, nodule formation and encapsulation of a variety of insect species. However, in most cases the description of an immune reaction of a certain insect is restricted to one or two measurable phenomena. Since a successful immune system depends on the interaction of all its parameters in a network as well as on the life circumstances (selection pressure) related to its ecological niche, it is important to analyze several components of the immune system within one insect species to come close to an understanding of the real competence of the system.
As examples, different aspects of the immune systems of the white cabbage butterfly, Pieris brassicae, of the Colorado potato beetle, Leptinotarsa decemlineata and of sawflies, Thentredinidae will be described.

The work was supported by the SNF, the BMBF and EU-network INCHECO




A17: IX International Congress of International Society for Developmental and Comparative Immunology, St Andrews (Scotland), 29 June- 4 July 2003

Hemocytes of Calliphora vomitoria (L.): morphological, histological and functional characterization

1Wang J.X., 2Trenczek T., and 2Angeli S.

1 School of Life Sciences, Shandong University, China
2 Institute of Zoology, University of Giessen, Germany

The most common hemocyte types of insects are prohemocytes, plasmatocytes and also granular cells. In addition, spherulocytes and oenocytoids have been described in Lepidoptera, cristal cells in Drosophila melanogaster and throbocytoids in some other Diptera. Here we report about hemocytes investigation of Calliphora vomitoria larvae and pupae by phase contract microscopy, fluorescence microscopy using antibodies and lectins as well as in vitro and in vivo functional assays. Four kinds of cells have been distinguished by phase contrast microscopy and were named: prohemocytes, plasmatocytes, thrombocytoids and oenocytoids. About 20 monoclonal antibodies raised against Manduca sexta hemocytes and one developed against Hyalophora cecropia hemocytes have been screened and five of them showed to bind specific epitopes of C. vomitoria hemocytes. Preliminary SDS-PAGE followed by Western blot analysis were made in the efford to characterise their specific antigens. Lectin labeling of C. vomitoria hemocytes revealed several differences in their carbohydrate composition. In particular, the lectin from Arachis hypogea [ß-Gal,(1-3),GalNAc] did not bind to throbocytoids whereas the lectin of Vicia villosa B4 [GalNAc] did, reflecting a difference in the GalNAc-composition of these cells. The phagocytic activity of C. vomitoria hemocytes was investigated by using bacteria (Escherichia coli, Micrococcus luteus, and Bacillus megaterium) as well as yeast (Saccharomyces cerevisae), all labeled with fluorescein-isothiocynate (FITC). The results showed that yeast was efficiently phagocytosed, mainly in vitro by plasmatocytes and in vivo by thrombocytoids. Finally, we compared the data of C. vomitoria hemocytes with those obtained with studies on hemocytes from Musca domestica and Drosophila melanogaster.




A16: IX International Congress of International Society for Developmental and Comparative Immunology, St Andrews (Scotland) 29 June- 4 July 2003

A comparative study of immune system and easy bleeding phenomenon of sawflies (Hymenoptera; Tenthredinidae)

Angeli S., Trenczek T.

Institute of Zoology, University of Giessen, Germany

The immune system has been well studied in respect both to humoral and cellular components in several insects. Hemocytes are characterised according to their morphological features, specific protein expressions and cellular activities, although there has been controversy over the number of hemocytes types and on the nomenclature adopted in different species. Till now in sawflies no results have been shown about their hemocyte and only one investigation is published on their hemolymph antibiotic activity. A very interesting phenomenon, called “easy bleeding”, has recently been discovered in several sawfly species. It is linked to an easy cuticular disruption with the formation of hemolymph drops along their cuticle surface, when larvae are bothered from other animals. This phenomenon is interpreted as a defence mechanism against predators. We hypothesised that “easy bleeding” sawflies might have stronger immune mechanism than “non-bleeding” in order to survive after periodically hemolymph losses. In this work we show various investigations on the immune system of eight different sawflies species. We have characterized sawfly hemocytes with phase contrast microscopy, immunohistochemistry and lectin labelling assays, in particular, of Athalia rosae and Gipinia hercyniae. In immunohistological analyses some monoclonal antibodies, specific for Manduca sexta hemocytes epitops, bind to cuticular layers in sawflies. In addiction several antibiotic tests on infected and non-infected larvae were made in the effort to verify the efficiency of their humoral immune response. As a first result we can clearly demonstrate that easy bleeders express a very sensitive humoral response, showing a high antibiotic activity after bacterial infection.

This research was supported by the EU network Insect Chemical Ecology (INCHECO) - Contract n. HPRN-CT-1999-00054




A15: 96. Jahresversammlung der Deutschen Zoologischen Gesellschaft und Deutschen Gesellschaft für Parasitologie, Berlin (Germany) 9-13 June 2003

Morphological and immunohistological investigations of “easy bleeding” and “non-easy bleeding” Tenthredinidae

Angeli S., Trenczek T.

Institute of Zoology, University of Giessen, Germany

An interesting defence strategy, called “easy bleeding”, has recently been discovered to be specific of several sawfly species (Hymenoptera: Tenthredinidae). When larvae of easy bleeding species are bothered from other animals, they quickly form drops of hemolymph along the cuticle, which is highly deterrent in feeding bioassays. This phenomenon has therefore considered as a defence strategy mainly against insect predators. In this work we hypothesise that easy bleeding sawflies might have stronger immune mechanisms than non-bleeding ones, in order to survive after hemolymph exposure and a possible microorganismal challenge. Investigations were made with phase contrast microscopy, immunohistochemistry and lectin labelling assays. An easy bleeder, Athalia rosae, has very well defined plasmatocytes, granular cells, a few big globular oenocytoids and a forth cell type similar to the spherulocytes of Manduca sexta. A non-easy bleeder, Gilpinia hercyniae (belonging to the Diprionidae family), has a lower hemocyte concentration and only plasmatocytes, granular cells and oenocytoids. Moreover, semi-thin sections of 15 sawfly species were made in order to perform histological investigations. Several monoclonal antibodies specific for M. sexta hemocytes and fluorescent lectins were then tested. Surprisingly, the results show that two of them (MS39 and MS77) bind specifically to cuticular layers, similar as the binding pattern of selected lectins. These results can now provide a powerful tool in order to explain the easy bleeding phenomenon at molecular level.

This research was supported by the EU network Insect Chemical Ecology (INCHECO) - Contract n. HPRN-CT-1999-00054




A14: XIX Congresso Nazionale Italiano di Entomologia, Catania (Italy) 10-15 June 2002

Stimoli chimici nelle interazioni tra individui di Ceratomegilla undecimnotata (Schneider) (Coleoptera, Coccinellidae) in fase di aggregazione

1Boddi G., 2Rosi M.C., 1Angeli S., 1Petacchi R. and 2Sacchetti P.

1 Scuola Superiore Sant’Anna di Studi Universitari e Perfezionamento, Pisa, Italia
2 Dipartimento di Biotecnologie Agrarie, Università di Firenze, Italia

Chemical stimuli involved in interactions among individuals of Ceratomegilla undecimnotata (Schneider) (Coleoptera Coccinellidae) in aggregations. - Among coccinellids, Ceratomegilla (=Semiadalia) undecimnotata is one of the most studied species because it migrates in large number towards overwintering sites (located both in hill or mountain) before diapausing. In this paper the results of bioassays carried out both in two-way olfactometer and arena are reported, in order to show the possible role of volatile and non volatile chemicals on such species. In all the experiments aggregating individuals of C. undecimnotata, collected from overwintering sites located either in France or Italy, have been used. In the olfactometer bioassays we evaluated the amount of time spent in each of the two arms; one arm was injected with pure air, while the other was injected with pure air passing through an aggregation of males or females. In arena three set of experiments have been performed. In the first two an heptane extract of both sexes C. undecimnotata elytra was applied either on glass and paper. In the third experiment the elytra were used as a dummy after having been washed with solvents characterised by different polarity. In all bioassays the behaviour of single individuals was observed for the described treatments, evaluating the time spent in the treated arena and the number of individuals that showed arrestment on the same arena. Data analysis showed that in olfactometer females spent a significantly lower time in the arm with aggregated males. In the arena bioassays males spent a longer time over the glass slide treated with male elytra extract, while in the paper experiments a lower number of females showed arrestment over the female extract treated areas. In the dummy experiments, a higher number of females were found over elytra treated with alcohol compared with those washed with chloroform and with those unwashed. Although these results are preliminary and will need more research, it is possible to show, for the first time in this species, how chemical stimuli can play a role in the interaction among aggregating individuals.




A13: XIX Congresso Nazionale Italiano di Entomologia, Catania (Italy) 10-15 June 2002

L’aggregazione in Ceratomegilla undecimnotata Schn. (Coleoptera: Coccinellidae): indagini preliminari sulla caratterizzazione chimica degli idrocarburi cuticolari e dei composti volatili presenti

1Angeli S., 1Boddi G., 2Dani F., 3Rosi C., 3Sacchetti P. and 1Petacchi R.

1 Scuola Superiore Sant’Anna di Studi Universitari e Perfezionamento, Pisa, Italia
2 Dipartimento di Biologia Animale e Genetica, Università di Firenze, Italia
3 Dipartimento di Biotecnologie Agrarie, Università di Firenze, Italia

Aggregation in Ceratomegilla undecimnotata Schn. (Coleoptera: Coccinellidae): preliminary analyses on chemical characterisation of cuticular hydrocarbons and volatile compounds. - Some species of ladybirds aggregate during summery and winter period. This phenomenon has been object of numerous studies in order both to comprise its ethological meaning, and -potentially- to improve the employment of these predators in organic farming techniques. Induction to summer migration seems correlated to variation in photoperiod, temperature and hormonal pattern while orientation towards the tops of mountains appears more related to visual stimuli. In this work, authors report some results in the attempt to identify contact and volatile compounds involved in the aggregation phenomena of Ceratomegilla undecimnotata. Analyses were made in GC-MS both of heptane extracts and volatiles collected using SPME (solid phase micro-extraction) technique. These experiments allowed us to identify hydrocarbon profiles of aggregate individuals. In particular approximately 28 compounds have been described, the most abundant of which are saturated and monounsaturated hydrocarbons with long chains from 23 to 33 carbons. No significant differences in hydrocarbons composition were found between males and females and also between an Italian and French population. Analyses of head spaces in SPME have shown low concentrations of volatile compounds, among which the presence of palmitic aldehyde is interesting. These data, although preliminary, are the first GC-MS investigation on potential pheromones in aggregates of C. undecimnotata and will be used in order to devise behavioural bioassays and to establish which is the function of identified compounds.




A12: Green-Tech® 2002 and 5th European Symposium of Industrial Crops and Products, The Netherlands, 24-26 April 2002

Effect of environmental on crop production and indigo yield in Polygonum tinctorium in Central Italy

1Angelini L., 1Tozzi S., 1Angeli S., and 2John P.

1 Dipartimento di Agronomia e Gestione dell’Agroecosistema, University of Pisa, Italy
2 Department of Agricultural Botany, School of Plant Sciences, Plant Science Laboratories, University of Reading, UK

In order to introduce introduce indigo-producing crops into European agriculture, research have been undertaken within a EU-funded research project (SPINDIGO). The current European market for indigo is supplied entirely by the synthetic product and the aim of this project is that a significant proportion of the European market will be met by natural indigo generating a useful income to the rural sector. Although natural dyes are rarely used in modern dyeing except by specialist fashion companies (e.g. to dye denim jeans), an increasing trend in textile industries is toward replacing synthetic products by natural ones and it has prompted research toward natural plant pigments. Natural indigo is indistinguishable from its synthetic counterpart: by extracting indigo from plants, blue dyes can be produced from a totally renewable resources. Natural indigo can be obtained from a wide range of tropical, sub-tropical and temperate plants from many different species, genera and families (Cardon and Chatenet, 1990; Stoker, 1997; Balfour-Paul, 1998). In tropical and sub-tropical areas, the plants most widely used for indigo production were Indigofera spp. (Martin-Leake, 1975). In temperate climates, the most commonly used species was Isatis tinctoria or dyers woad. Polygonum tinctorum (Ai), known as “Chinese indigo”, had been used in Japan, China and Russia for large-scale indigo production (Perkin and Everest, 1918; Hill, 1992). Polygonum tinctorum is a subtropical annual herbaceous plant, belonging to the family Polygonaceae with large dark bluish-green and it was introduced in Europe at the end of the eighteenth century. It has some glycosides as secondary metabolites, the major one is a colourless glucoside called indican (indoxyl b-D-glucoside). When the plant leaves are put in water, indican is extracted and it is degraded to indoxyl and glucose. A dimerization of this indoxyl by air oxidation follows and indigo is formed: this is the compound that is commonly used as a blue dye since ancient time (Minami, 2000). Although indigo can be obtained from plants in large amounts, the decrease of the natural indigo use had been related to the fact that the process is not well understood. The precursor pathway may also be relied to the intensity of sunlight, which has been found to play a vital role in the production of indigo yield (Stoker et al., 1998). P. tinctorum is a relatively new species for Italy and research is needed to improve cultivation methods in order to produce plant material with the highest quality and the lowest production costs. Research has been carried out within Spindigo project, closely cooperating with other European scientific institutions, in order to better understand the effect of environment on crop production and indigo yield. Three P. tinctorum populations and three sowing times were tested under field conditions in Central Italy in a split plot experimental scheme with four replications. To evaluate maximum crop yield, plants were maintained under optimum nutrient and water supply conditions. The changes in air temperature, rainfall, global radiation and photosynthetically active radiation (PAR ) were recorded along the growing season. The productive determinations (fresh and dry leaves, stems and total plant yield in t ha-1; leaves:stems ratio and Harvest Index) were performed on a minimal area of 2 m2 per plot on the middle rows. Plants had been sampled prior of each harvest and fresh leaves were extracted in an adequate water volume. Indigo content was determined spectrophotometrically at 600 nm. Indican content was assessed by HPLC coupled with an ELS (Evaporating Light Scattering) detector and determined against a calibration curve obtained with an indican standard solution. Changes in PAR had been recorded and had been plotted against variation in leaves and indigo yield.




A11: Proc. of the VII European Symposium on Insect Taste and Olfaction, Villasimius (CA, Italy), 22-28 September 2001

Purification of Chemosensory Proteins (CSP) in Locusta migratoria

1Ban L., 2Brandazza A., 3Angeli S., 1Zhang L., 1Yan Y. H. and 2Pelosi P.

1 Department of Entomology, Agricultural University of Beijing, China
2 Dip. Chimica e Biotecnologie Agrarie, University of Pisa, Italy
3 Scuola Superiore S. Anna; 56124 Pisa, Italy

Locusta migratoria represents the major pest in Asia,producing enourmous damage to crops. Based on our previous information on the related species Schistocerca gregaria, we have started investigating the biochemical mechanisms of chemical communication in this insect, focusing our attention on soluble proteins of chemosensory organs.
Electrophoretic analysis both in native and denaturing conditions of crude extracts of antennae, tarsi and palpi, revealed the presence of acidic proteins of low molecular weight. Some of these bands were present only in antennal extracts, while others were present also in tarsi and palpi. These proteins were purified by gel filtration chromatography, followed by preparative electrophoresis in native conditions.
N-terminal sequences have indicated such proteins to be members of the family of Chemosensory Proteins (CSPs). Amplification of the relative genes by PCR with degenerate primers, cloning and sequencing allowed the establishment of nucleotide sequences encoding several members of this group. Their derived amino acid sequences share about 90% of their residues with CSPs of S. gregaria and between 50 and 60% with those described in L. migratoria.
Polyclonal antibodies have been raised in mice agains the protein purified from the antennae and are currently used in immunocytochemistry experiments to label its sites of production and accumulation within the chemosensory organs. 
Western blot experiments have been used to monitor the expression of these proteins during the developmental stages of the insect.
As in the case of S. gregaria, a similar protein was purified from the wings, where it is associated with organic compounds of low volatility, whose structures are currently being investigated.




A10: Proc. of the VII European Symposium on Insect Taste and Olfaction, Villasimius (CA, Italy), 22-28 September 2001

Structure and function of Chemosensory Proteins (CSP) in insects

1Picone D., 2Crescenzi O., 3Scaloni A., 4Angeli S. and 5Pelosi P.

1 Dipartimento di Chimica, University of Napoli, Italy
2 Dipartimento di Chimica Organica e Biochimica, University of Napoli, Italy
3 I.A.B.B.A.M. - Centro Internazionale Servizi di Spettrometria di Massa, CNR, Napoli, Italy
4 Scuola Superiore S. Anna, 56124 Pisa, Italy
5 Dip. Chimica e Biotecnologie Agrarie, University of Pisa, Italy

Chemosensory proteins (CSPs) is the name given to a class of small soluble proteins found in chemosensory organs of insects. Some charcteristics suggest that they represent a second class of binding proteins for chemical stimuli. These proteins are slighly smaller than OBPs, generally, but not always acidic and very soluble. Like OBPs, their concentration in chemosensory structures is extremely high. The first protein of this class was identified in Drosophila, later members were described in most insect Orders, from the very primitive Phasmids to Lepidoptera and Hymenoptera. Their amino acid sequences are better conserved than OBPs, with an average of about 40% of common residues, even between very distant species. In apparent constrast with this charactersistics, polyclonal antibodies raised agaist CSPs of different species do not cross-react. Two pairs of nearly adjacent conserved cysteines are linked by two disulphide bridges, that apparently do not contribute to the three-dimensional structure of the molecules. Immunocytochemical experiments have indicated that they are highly concentrated in the sensillar limph of chemosensory hairs. Members of this family have been identified in the ejaculatory bulb of Drosophila, the same organ secreting the sex pheromone, and in subcuticular cells. The protein extracted from this latter source contains, as endogenous ligands, long-chain hydrocarbons. These observations seem to indicate that CSPs might be involved, not only in the perception, but also in the release of pheromones. We have expressed one of the CSPs of Schistocerca gregaria and the Drosophila OS-D in bacterial systems, in order to produce antibodies for immunocytochemical localisation and to obtain enough protein for structural studies. The CSP of S. gregaria has also been obtained in N-15 enriched form and used in NMR conformational studies. We report preliminary data on the three-dimensional structure of this protein, composed of six alpha-helices.




A9: XXI International Congress of Entomology, Foz do Iguassu (Brazil), 20-26 August 2000

Chemosensory proteins in Schistocerca gregaria

Angeli S.

Scuola Superiore S. Anna, 56124 Pisa, Italy

The desert locust Schistocerca gregaria is one of the major crop pest in Africa and the Middle East. Recently, chemoreception of the species has been investigated with regard to ecological, behavioral and physiological aspects. An aggregation-maturation pheromone and an egg-pod attraction pheromone have been isolated and characterized and the fine-structure of antennal sensilla was studied. Here we describe the biochemical characterization and the immunocytochemical localization of the first family of chemosensory proteins (CSP) expressed in Orthoptera. Three acidic and soluble proteins of 14 kDa were purified, each from distinct chemosensory organs (antennae, tarsi, and labrum) of crowed-reared locusts. The N-terminal sequences were obtained and were found to be similar to each other. They exhibit significant homology with a sub-class of putative chemoperception proteins, expressed from Phasmids to Diptera. A large quantity of the tarsi-specific protein was purified from females and used for chemical characterization, polyclonal antibody preparation and binding assays. In TEM-immunocytochemical of chemosensory organs, the antibody labelled specifically the receptor lymph of contact, terminal pore sensilla. Therefore we designed degenerated primers from the N-sequence and were able to amplify, by RT-PCR, the nucleotide sequences from mRNA isolated from the tarsi of one female. After cloning and sequencing, the sequence analysis showed five isoforms, all encoding for proteins 109 amino acids long. Comparison of peaks of the mass-spectrometry analysis of the native protein with the theoretically calculated molecular mass from the five cDNAs, showed a completed overlap, suggesting that this isoforms are all expressed in single animals without any post-translaction modifications. Therefore, we decided to express an isoform in E. coli. The chemical analysis of all soluble recombinant protein showed no differences with the native protein in terms of PAGE analysis, mass-spectrometry, disulfide bridges dispositions and circular dichroism. Crystallization experiments and ligand-binding assays of the recombinant from are now in progress. Although the specific function of these proteins is still unknown, their high degree of homology with the 4 conserved cysteines, and their expression in chemosensory organs of large number of species have suggested a role in chemoreception. Recently a member of this family was found to bind the Drosophila pheromone vaccenyl acetate. In Orthoptera, our experimental data suggest a role for these proteins in contact chemoreception, for instance in response to chemicals on surfaces like cuticular hydrocarbons. No binding of radioactively labelled glucose or bicarbonate was detected.




A8: Proc. of VI European Symposium on Insect Taste and Olfaction, Tutzing (Germany), 5-10 September 1999

Immunocytochemical distribution of a chemosensory protein of Carausius morosus

Minnocci A., Angeli S., Monteforti G., and Petacchi R.

BioLabs - Scuola Superiore Sant'Anna, Via Carducci 40 I- 56127 Pisa (Italy)

Isolation of soluble low molecular weight proteins in antennae, tarsi and labrum of S. gregaria, clearly showed the existence of a new class of Chemosensory protein (Angeli et al., 1999) likely to be involved in chemical communication. Similar proteins was also demonstrate to be present in Phasmids (Mameli et al., 1996), in particular in Carausius morosus (Tuccini et al., 1996). These proteins belong to a family, whose first member was identified in the antennae of D. melanogaster and named OS-D-like, described in different Orders of insects, from Phasmids to Lepidoptera and relatively well conserved across evolution. Polyclonal antibodies used to immunodetect these proteins in Schistocerca gregaria, showing that it is localized in contact chemosensory hairs of tarsi, antennae and labrum nor in olfactory sensilla. 
We are currently investigating the ultrastructural localization of a CSP in the different sensory organs of this stick insect.

Angeli S., Ceron F., Scaloni A., Monteforti G., Minnocci A., Petacchi R. and Pelosi P. 1999. Structural characterisation, cloning and immunocytochemical localisation of Chemoreception proteins from Schistocerca gregaria. (in press)
Mameli M., Tuccini A., Mazza M., Petacchi R., Pelosi P., 1996. Soluble proteins in chemosensory organs of Phasmids. Insect Biochem. Mol. Biol. 26: 875-882.
Tuccini A., Maida R., Rovero P., Mazza M., Pelosi P.,1996. Putative odorant-binding proteins in antennae and legs of Carausius morosus. Insect Biochem. Mol. Biol. 26: 19-24.




A7: Proc. of the VI European Symposium on Insect Taste and Olfaction, Tutzing (Germany), 5-10 September 1999

Major chemosensory proteins of Phasmids

1Marchese S., 1Brandazza A., 1Ceron F., 2Angeli S., 2Mionnocci A., 3Mazza M. and 1Pelosi P.

1 Dipartimento di Chimica e Biotecnologie Agrarie, University of Pisa, Italy
2 Scuola Superiore S. Anna, 56124 Pisa, Italy
3 Dipartimento di Scienze, Uomo e Ambiente, University og Pisa; Italy

The chemosensory organs of Phasmids express very high levels of soluble proteins of the class referred to as OS-D like or CSP (Chemosensory Proteins). Proteins of this class are also expressed in other orders of insects, such as Lepidoptera, Diptera, Imenoptera, Orthoptera and Blattoidea. 
Here we describe the cloning and sequencing of some members of this class of proteins in the Phasmid species Eurycantha calcarata and Carausius morosus. Mature polypeptides are 100 to 117 residue long and contain four conserved cysteines. The same proteins or similar ones appear to be expressed in the antennae, in the tarsi and in other parts of the body. Polyclonal antibodies prepared against purified proteins from both species, as well as against a similar protein of S. gregaria, indicated no cross-reactivity, despite the sequence similarities between the three proteins. Each antiserum, however, stained bands of similar molecular weight in different chemosensory organs of the same species.
A comparison between all the known sequences of CSPs in different orders of insects is also presented and discussed.




A6: Proc. of the VI European Symposium on Insect Taste and Olfaction, Tutzing (Germany), 5-10 September 1999

Bacterial expression of a chemosensory protein (CSP) of Schistocerca gregaria

1Angeli S., 2Marchese S., 2Brandazza A., 1Petacchi R. and 2Pelosi P.

1 Scuola Superiore Sant'Anna 56124 Pisa, Italy
2 Dipartimento di Chimica e Biotecnologie Agrarie, University of Pisa, Italy

We have recently isolated from chemosensory organs of Schistocerca gregaria, several polypeptides of low molecular weight (around 14 kDa) and acidic nature. Their amino acid sequences revealed that all the isolated proteins belong to the same sub-family, whose first member was identified in Drosophila melanogaster and named OS-D. The five gene products, identified in both sexes, contain 109 amino acids, are very similar to each other and present four cysteine residues involved in two disulphide bridges, as demonstrated by mass spectrometry. This technique also confirmed the calculated molecular weights and excluded the presence of additional post-translational modifications. 
Here we report the cloning of one of these genes into a pET-5 vector and the expression, purification and characterisation of the recombinant protein. The protein is expressed with an additional residue of methionine at the N-terminus, as the sole difference with the native polypeptide. Yields were in the range of 50-70 mg of soluble protein per litre of bacterial colture. Purification was accomplished by standard methods, involving ammonium sulphate fractionation, ion-exchange chromatography and gel filtration. The recombinant protein showed chemical properties identical with those of a native sample.




A5: XIII Congress European Chemoreception Research Organization (XIII ECRO), Siena, Italy, 8-12 September 1998

Cloning of soluble chemo-sensory proteins in Phasmids

1Marchese S., 1Ceron F., 1Angeli S., 2Mazza M., 3Picimbon J.F., 3Leal W.S. and 1Pelosi P.

1 Dipartimento di Chimica e Biotecnologie Agrarie, University of Pisa, Italy
2 Dipartimento di Scienze, Uomo e Ambiente, University of Pisa, Italy
3 NISES, Tsukuba, Japan

Based on our previously reported N-terminal sequences, we have amplified by PCR, cloned and sequenced genes encoding soluble proteins in chemosensory organs of two species of Phasmids, Eurycantha calcarata and Carausius morosus. Several related sequences have been amplified in both species. Here we report the complete amino acid sequences of three proteins expressed in the antennae of E. calcarata and one in the tarsi of C. morosus. They consist of polypeptides of 100-117 residues, bearing four conserved cysteines. All exhibit significant similarity with a recently discovered class of chemosensory proteins, including Drosophila melanogaster OS-D, Cactoblastis cactorum CLP-1 and five members of Schistocerca gregaria (Angeli et al., ECRO XIII, 1998). 
One of the E. calcarata sequences is identical in its first 33 residues with that determined by direct Edman degradation on the purified protein, while in C. morosus the sequence deduced from the cDNA is markedly different from the N-terminal information obtained on the isolated protein. A comparison between proteins of this class across different orders shows that they are well conserved, when compared with OBPs.
Polyclonal antibodies prepared against purified proteins from both species, as well as against a similar protein of S. gregaria, indicated no cross-reactivity, despite the similarity between the three proteins. Each antiserum, however, stained bands of similar molecular weight in different chemosensory organs of the same species. To test their hypothesised role in carbon dioxide sensing, we performed binding experiments with radioactive bicarbonate, but results were negative in the conditions employed. Being the proteins of this class probably involved in chemoreception, as suggested by their tissue localisation, we propose the general name of CSP (ChemoSensory Protein).




A4: XIII Congress European Chemoreception Research Organization (XIII ECRO), Siena, Italy, 8-12 September 1998

Chemosensory proteins(CSP) of Schistocerca gregaria

1Angeli S., 2Ceron F., 3Scaloni A., 3Monti M., 1Petacchi R., 1Minnocci A., 1Monteforti G. and 2Pelosi P.

1 Scuola Superiore S. Anna, Pisa, Italy
2 Dipartimento du Chimica e Biotecnologie Agrarie, University of Pisa, Italy
3 CISESMA - IABBAM, CNR, Napoli, Italy

Soluble proteins of chemosensory organs have been described in several orders of insects and include pheromone- and odorant-binding proteins, as well as other polypeptides of similar structure probably involved in gustatory perception. Information of this type is not available for Orthoptera, despite the high economical interest of several species of this order.
In our search for OBP-like proteins in Schistocerca gregaria, we have isolated several polypeptides of low molecular weight (around 14 kDa) and acidic nature from chemosensory organs, such as antennae, tarsi and upper labrum. N-terminal sequencing revealed that all the isolated proteins belong to the same sub-family, including Drosophila melanogaster OS-D and Cactoblastis cactorum CLP-1. By using degenerate primers and PCR, we have amplified, cloned and sequenced genes encoding five members of these proteins in tarsi of both sexes. The five gene products contain 109 amino acids, are very similar to each other and present four cysteine residues probably involved in two disulphide bridges. Calculated molecular weights are identical to those measured by mass spectrometry, indicating the absence of other post-translational modifications.
Polyclonal antibodies, raised against the purified protein, have been used in immunocytochemical localisation. Both in antennae and tarsi, single-pore gustatory sensilla are labelled, but not olfactory sensilla. Labelling is limited to the sensillar lymph.  The same polyclonal antibodies have indicated in Western blot experiments that the synthesis of these proteins, both in antennae and tarsi, starts at the second instar and reaches high levels of expression at the third instar. A role in carbon dioxide sensing has been suggested for the homologous protein of C. cactorum. Binding of labelled bicarbonate, however, has been unsuccessful with the proteins of S. gregaria, while other prospective ligands are being tested.




A3: XVIII Congresso Nazionale Italiano di Entomologia (XVIII CNIE), Maratea (Italy), 21-26 June 1998, spoken presentation

Studi sulla percezione degli odori in Schistocerca gregaria (Orthoptera: Acrididae)

1Angeli S., 1Minnocci A., 1Petacchi R., 2Monti M., 2Scaloni A., and 3Pelosi P.

1 Scuola Superiore di Studi Universitari e di Perfezionamento S.Anna, Pisa
2 Centro Internazionale Servizi di Spettrometria di Massa, CNR, Napoli
3 Dipartimento di Chimica e Biotecnologie Agrarie, Università di Pisa

La locusta del deserto Schistocerca gregaria è un insetto polimorfico che presenta due fasi: quella solitaria e quella gregaria,quest'ultima particolarmente dannosa in agricoltura. Il passaggio fra le due fasi è reversibile in ogni stadio di sviluppo ed è mediato da sostanze chimiche generalmente volatili appartenenti alla classe dei feromoni. Altri composti volatili, quali l'anisolo e molecole di struttura simile, sono stati riconosciuti come feromoni di aggregazione e sono responsabili della formazione dei grossi sciami devastatori. La comprensione dei meccanismi della comunicazione chimica e la possibilità di modificarla sono al centro di numerose ricerche finalizzate a combattere l'insorgenza di queste periodiche infestazioni. L'indagine biochimica ha portato alla identificazione, purificazione e parziale caratterizzazione di proteine solubili, di basso peso molecolare, probabilmente coinvolte nella percezione di stimoli chimici. In particolare, i tarsi e l'apparato boccale esprimono abbondanti proteine di circa 14 kDa, le cui sequenze amminoacidiche N-terminali risultano simili a proteine della stessa classe da noi precedentemente purificate in alcune specie di Fasmidi, nonché a quelle descritte da altri ricercatori in Ditteri, Imenotteri e Blattoidei. Al fine di chiarire il ruolo di tali proteine nella chemiorecezione, è opportuno studiarne la capacità legante verso gli odori e definirne la localizzazione tissutale. Per affrontare quest'ultimo problema, mediante un approccio di immunoistochimica, sono stati prodotti anticorpi policlonali contro la proteina di 14 kDa purificata dai tarsi. Saggi di immunoblotting, effettuati con tale antisiero parzialmente purificato, hanno confermato la esclusiva espressione della proteina nei tarsi e nell'apparato boccale, come già indicato dalle analisi elettroforetiche e dalle informazioni di sequenza. L'indagine morfologica è stata effettuata attraverso tecniche di microscopia elettronica a scansione e a trasmissione. I risultati finora ottenuti, confermando i dati in letteratura, mostrano diversi tipi di sensilli chemiorecettoriali, in particolare sulle antenne, nella porzione apicale dei palpi mascellari e labiali, sulla superficie interna del labbro superiore e nella porzione ventrale dei pulvilli di ciascun paio di zampe. Questi risultati costituiscono i primi dati sui meccanismi biochimici della chemiorecezione negli Ortotteri e potranno aprire la strada a nuove strategie di lotta contro l'insetto studiato.




A2: Proc. of the V European Symposium on Insect Taste and Olfaction (V ESITO), Villasimius (Italy), 20-26 September 1997

Morphological and biochemical investigation of chemosensory organs in Phasmidae

1Mameli M., 2Monteforti G., 2Angeli S., 2Minnocci A., 2Petacchi R., 1Tuccini A., and 1Pelosi P.

1 Dipartimento di Chimica e Biotecnologie Agrarie - Università di Pisa, Italy
2 Scuola Superiore di Studi Universitari e Perfezionamento Sant'Anna, Pisa, Italy

Phasmids are frequently used as model for many biological experiments in insects. In fact they are simple to rear and their dimensions are usually enough big to allow physiological and biochemistry assays. Moreover they are a very primitive heterometabolous order of insect, in which are known both parthenogenetic and amphigonic species. The chemical communication between sexes has still not been elucidated, but the fact that they have a very long life cycle give suggestion for the presence of a specialized olfactory system. All these characteristics put this order in a different position in respect to the holometabolous order (e.g. Lepidoptera), where chemosensory transduction is usually studied. We have morphologically and biochemically investigated several Phasmid species in order to draw a more complete pattern of information on their chemosensory system and to give some insights on the phylogenetic evolution in odour perception. From the antenna, legs and mouthparts, that are known in insect to be involved in chemosensory processes, we have purified some small, soluble proteins (Mameli et al., 1996) that can be divided mainly in two subclasses and in another species, Sipyloidea sipylus, another protein, antennal specific, that constitutes the only member of a third subclass. In parallel with the biochemistry identification of proteins we have performed scanning and transmission electronic microscopy to study olfactory sensilla structure and function, in the parthenogenetic females of Carausius morosus and both sexes of Eurycantha calcarata and Extratosoma tiaratum. The antenna of these species have in commune a characteristic glandular structure, called bump, pierced by the sectretory ducts of numerous gland cells on dorsal surface and a distribution of sensilla that shows a very marked increasing in the second half of flagellum, in agreement with its huge dimension that can arrive to more than 4 cm. In Carausius morosus antennae we have identified different types of mechanosensitive sensilla (peg-like. Bristle like and campaniform), a small number of poreless thermohygrosensitive and three types of chemosensilla. The fist type is a gustative hair-shaft with fluted aporous walls and spatulate tip. The cross sections of this hair shows a double lumen with five unbranched dendrites inside the innervated one (5x2+1 or 7x2+3). Another is an “hair-like” olfactory sensillum with blunt tipped and smooth walls, perforated by pores and with spoke channels. The number of sensory cells is comprised between four and six. The third type is a “peg-like” sensillum, less abundant and smaller, with a thin cuticular wall and high density pores. The cellular components of all these sensilla consist of a greater and variable (5-22) number of sensory neurons. The dendritic segments are first enclosed in a common sheath and later divided into numerous branches. In this species two soluble proteins have been purified, antennal and leg specific (Tuccini et al., 1996; Mamenli et al., 1996). One is a 19 kDa protein that shares a 30 % amino acid identity with Drosophila melanogaster OS-D or A 10 (McKenna et al., 1994; Pikielny et al., 1994) and belong to the first sub-class of putative OBPs (Odorant Binding Proteins) of Phasmids. The second is a 15 kDa protein that can be grouped in the second sub-class and that has a greater similarity with OS-D or A-10. In the two amphigonic species studied, Eurycantha calcarata and Extratosoma tiaratum, there is a dimorphism between sexes in the flagellum, but the number and the types of sensilla do not differ, implying a similar function in both sexes. In these species the last segments of the antenna, that generally in insects are more involved in the chemosensory perception, reach a density of 1000 sensilla/mm2 and present three different sensilla types in E. calcarata and four in E.tiaratum. In E. calcarata antennae we have identified also the presence of sensilla coeloconica-like and this is interesting because in both species we have purified 14 kDa soluble proteins from antennae and legs that belong to the second sub-class, similar to OS-D or A 10 and this protein, in Drosophila, has been localized in sensilla coeloconica. All the sub-classes of soluble proteins identified and purified in Phasmids don’t show a primary structure similarity with the know Lepidopteran OBPs, and this is probably due to the evolutionary distance between the two orders.




A1: Proc. of the V European Symposium on Insect Taste and Olfaction (V ESITO), Villasimius (Italy), 20-26 September 1997

Chemioreception in Schistocerca gregaria (Orthoptera, Acrididae)

1Angeli S., 2Long Z., 1Minnocci A., 1Petacchi R., and 3Pelosi P.

1 Scuola Superiore di Studi Universitari e Perfezionamento Sant'Anna, Pisa, Italy
2 China Agricoltural University, Beijing, PRC
3 Dipartimento di Chimica e Biotecnologie Agrarie, University of Pisa, Italy

The desert locust Schistocerca gregaria is one of the major threats to crops in Africa and Asia. The onset of the gregarious phase is triggered by volatile chemicals. Interphering with the olfactory perception of this species could therefore control aggregation and thus reduce its devastation effects.
Biochemical aspects of olfaction have been investigated in several insect species, belonging to the orders of Lepidoptera, Diptera, Hymenoptera and Phasmatodea, but no data have been reported in Orthoptera. Most of the research in other orders has been concerned with soluble proteins, present at high concentration in the lymph of sensory hairs and called OBPs (odorant-binding proteins). These proteins are subdivided in two classes, pheromone-binding proteins (PBPs) and general odorant-binding proteins (GOBP).
Here we describe the purification of putative OBPs from sensory parts of S. gregaria. A first screening of soluble proteins in different parts of the body, performed by SDS-PAGE, revealed the presence of low molecular weight bands in all the sensory parts (antenna, legs, mouth), but not in the other extracts. The same extracts, when analyzed by native PAGE, showed to contain fast migrating acidic proteins. No significant differences were observed in the electrophoretic patterns between sexes. 
One of the most abundant of them, with an apparent molecular weight of 14 kDa, was purified from the tarsi, using standard chromatographic techniques. Its N-terminal sequence (NH2-EEKYTTKYDNVNLDEILANDRLLNKYVQQLLEXD-) showed significant similarity with Drosophila OS-D (48%) and other proteins o same size purified from several Phasmid species. A very similar protein was also purified from the labrum by preparative electrophoresis. Both proteins migrate on SDS-PAGE with the same apparent molecular weight and show the same isoelectric point (5.1) on a IEF gel in a gradient of ampholines. An affinity column, prepared with the antiserum against a 15 kDa of Eurycantha calcarata, was effectively used for purifying the proteins of S. gregaria. A specific degenerated primer has been synthesized on the basis of N-terminal sequence and is currently used for amplifying the gene encoding this protein. At the same time, a morphological investigation, performed at the electron scanning microscope, revealed several types of chemiosensilla in the same organs expressing the 14 kDa protein.



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