Abstracts - Rafael Carvalho da Silva


Rafael Carvalho da Silva¹*, Amanda Prato da Silva¹, Izabel Cristina Casanova Turatti² and Fábio Santos do Nascimento¹

1 Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Departamento de Biologia, Universidade de São Paulo; rcsilva2812@usp.br; amandaprato@usp.br; fsnascim@usp.br

2 Faculdade de Ciências Farmacêuticas de Ribeirão Preto, Departamento de Ciências Farmacêuticas, Universidade de Ribeirão Preto; izcristu@usp.br

* Correspondence: rcsilva2812@usp.br

Variation existing between two genders in the animal kingdom has been proposed due to the sexual selection. 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 it is known that some species express 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 traits to orient themselves we still do not know. Therefore, our aim was to analyze if there are expression of different chemical compounds between females and males of three species of Polistinae wasps. Colonies of Polistes versicolor, Mischocyttarus cerberus and Polybia occidentalis were collected and kept in laboratory. Males and females were separated as they emerged and stored in the freezer until the chemical extractions. Each individual was individualized in glass vials and washed with apolar solvent hexane during one minute. 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. cerberus p=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 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% of contribution; P. versicolor z-C34 – 26.31% cont.; P. occidentallis n-C29 – 21.4% cont.). The existence of different chemical compounds for the identification of males and females was already well documented for many species of bees and some ants. Our preliminary results suggest that those chemical differences can be used and important for individuals during sexual encounters and still be use to avoid wrong courts by males.