Insect-corn kernel interaction: Chemical signaling of the grain and host recognition by Sitophilus zeamais

ZAIO, YP; PESCHIUTTA M.L.; DAMBOLENA, J.S; ZUNINO M.P.; USSEGLIO, V.L.; MERLO, C.

Valparaíso

Congreso; V Congress of the Latin American Association of Chemical Ecology (ALAEQ); 2018

In living organisms, the cuticle has structural functions and is involved through chemical signaling in biological interactions such as plant-insect and provides protection against biotic and abiotic factors, thereby avoiding desiccation or predators? attack. The objective of this study was to investigate the participation of the epicuticle in the interaction of the maize kernel and the maize weevil Sitophilus zeamais. For this study the extraction of epicuticle was carried on and the extract was analyzed by GC-MS. Digital photographs of cross sections of grains with and without epicuticle were taken, and behavior bioassays were carried out with both grains with and without epicuticle and epicuticle extracts. The GC-MS analysis of the epicuticle extract demonstrated the presence of aliphatic hydrocarbons, alcohols, ethers, fatty acids, sterols and their derivatives. The results of preference bioassays showed that the epicuticle of maize has a primordial role in its interaction with S. zeamais participating in the recognition and attraction to the food source. According to these results, in the assay of kernels? susceptibility to insect attack, kernels without epicuticle were significatively less damage than kernels with epicuticle. In progeny assays, the exposition of S. zeamais adults to kernels without epicuticle caused a reduction in progeny, indicating that it could regulate the reproduction of S. zeamais. In addition, the compounds present in the epicuticle extract may act as signalling molecules and developmental regulators. This study reveals the effect of the maize kernel epicuticle on Sitophilus behavior and contributes to the understanding of their interaction.