X ENCONTRO BRASILEIRO DE ECOLOGIA QUÍMICA X Brazilian Meeting of Chemical Ecology MEMORIAL MEETING FOR PROF. JOSÉ TÉRCIO B. FERREIRA (1952-1997)
Type of the Presentation: ( Poster)
CAN EPICUTICULAR HYDROCARBONS BE USED AS SEXUAL CUES IN POLISTINAE WASPS? Rafael Carvalho da Silva¹*, Amanda Prato da Silva¹, Diego Santana Assis¹, André Rodrigues de Souza¹, Izabel Cristina Casanova Turatti² and Fábio Santos do Nascimento¹ 1
2
*
Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Universidade de São Paulo;
[email protected];
[email protected];
[email protected] Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento x, Universidade de Ribeirão Preto;
[email protected] Correspondence:
[email protected]
Variation existing between two genders in the animal kingdom has been proposed due sexual selection action. Individuals of two sexes have to find each other to mate, so it is expected that they can be able to recognize those differences in the environment. Among social wasps is known that in some species there are different expressions of colorful marks over the bodies of males and females and these features can be evolved in sexual recognition contexts, however if they also use chemical tracks to orient themselves we still do not know. Therefore, our aim was to analyze if at first there are expression of different chemical compounds between females and males of three species of Polistinae wasps. Nests of Polistes versicolor were collected in Viçosa, Minas Gerais at University of Viçosa and kept in laboratory, males and females were collected as they emerged and placed at the freezer until the chemical extractions, the same was done with nests of Mischocyttarus cerberus and Polybia occidentalis in Ribeirão Preto, São Paulo at University of São Paulo. Each individual was individualized in glass vials and washed with apolar solvent hexane for a minute, after that the samples were analyzed in the system of Gas Chromatography coupled to Mass Spectrometry. Data were analyzed with Past version 2.17c Software. Significative differences were found between the males and females of the three species (M. cerberu sp=0,0001; P. versicolor p=0,0001; P. occidentallis p=0,0001) based on the permutation tests (9999 permutations) and those differences were represented by quality or quantity of certain compounds. Discriminant analyzes have showed that for each species one class of compound was important to separate females and males (M. cerberus 15-;13-;11-;9-MeC31 - 14,27% contribuition; P. versicolor z-C34 – 26,31% cont.; P. occidentallis n-C29 – 21,4% cont.). The existence of different chemical identification of males and females was already well documented for many species of bees and some ants. Although we have not performed behavior experiments simulating encounters by females and males of those species, our preliminary results may be used to suggest that those chemical differences can be noticed and import for them during sexual encounters and still be use to avoid wrong courts by males.
