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Abstracts - Caroline Rech

Contact sex pheromone of DiabroticaviridulaeDiabroticaspeciosa (COLEOPTERA: CHRYSOMELIDAE)

Caroline Rech1*, Mayara De Carli1, Arodi Prado Favaris2, José Maurício Simões Bento2and Cristiane Nardi1

1 Department of Agronomy, Midwestern State University, Guarapuava, Paraná;

2Department of Entomology and Acarology, University of São Paulo, Piracicaba, São Paulo;

* Correspondence: caroline_rech@outlook.com

Cuticular hydrocarbonsare important signals to insect communication, being usually associated to recognition of nestmates, defense, sexual selection or sexual isolation between related species. Here, we investigated the role of cuticular chemical compounds of female for conspecific male mating induction in Diabrotica speciosa e Diabrotica viridula. We obtained extracts from 6 days-old female, via elytra excision and immersion in hexane during 24 hours. Behavioral bioassays were carried out using plastic cages (10 cm diameter) containing 40 male andtwo glassrods treated with female conspecific extractsor only hexane (n=5). During 2 hours, we observed the male mating attempts and registered the number of responsive individuals. These extracts were also tested in Y-tube olfactometer (n=40), in order to investigate whether these extracts could demonstrate some long-term attraction of males. Diabrotica speciosa e Diabrotica viridula males showed characteristic pre-copula and copula behaviors extruding the aedeagus toward the glass rods, with 30% and 32,5% of male mating attempts, respectively. In Y-tube olfactometer, female extracts were not attractive to conspecific males, attesting the exclusive contact effect of cuticular compounds. Preliminary chemical analysis in gas chromatography/mass spectrometer showed conspicuous differences in male and female extracts of both species.These findings provide evidences that cuticular chemicalcues act in mate recognition, as reported for others Chrysomelidae (Geiselhardt et al., 2009; Campbell and Meinke, 2010). Further studies will be done to identify the action of each chemical compound in male mating induction and clarify the implications of contact cuticular compounds in sexual isolation of these species.

Acknowledgement: The authors acknowledge the financial support from National Institute of Science and Technology – Semiochemicals in Agriculture (FAPESP and CNPq -– grants #2014/50871-0 and #465511/2014-7, respectively) and FundaçãoAraucária.

Refs.

1. Geiselhardt, S. et al., J. Chem. Ecol.35, 1162, 2009.

2. Campbell, L. A. and Meinke, L. J. An. Entomol.Soc.Am.,103, 925, 2010.