Semioquímicos envolvidos na interação intraespecífica de Eupalamides cyparissias (Fabricius) (Lepidoptera: Castniidae) e Automeris liberia (Cramer) (Lepidoptera: Saturniidae) pragas de Arecaceae

Abstract

The Lepidoptera Eupalamides cyparissias Fabricius, 1776 (Castniidae) and Automeris liberia Cramer, 1780 (Saturniidae) are pests that damage the plants of the family Arecaceae of economic significance as the oil palm (Elaeis guineensis Jacq.) And coconut tree (Cocos nucifera L.). In the larval stage E. cyparissias forms galleries inside the stipe. In the larval stage A. liberia defoliation the aerial parts of the plant. One way to reduce the use of insecticides and control expansion and damage of pests in agricultural environments is through behavioral control using semiochemicals (pheromones), a useful tool for controlling and monitoring pests that has been used in some crops. This work investigated the semiochemicals involved in the intraspecific interaction of E. cyparissias (Castniidae) and A. liberia (Saturniidae). Pupae and larvae were obtained in plantations of oil palm from the Agropalma Group, Thailand-Pa. The material was kept in the laboratory at 25.2 ° C and 12:00 hours (Scotophase: Photophase) until obtention of adults. Scanning electron microscopy (SEM) was performed to verify the morphology and typology of sensilla using antennas of E. cyparissias and A. liberia insects of both sexes with 24-48h. Histological analysis was performed with the sexual gland of A. liberia. The extracts of both insects were obtained by extraction with HPLC grade hexane solvent and analyzed by GC / EAD, GC / FID and GC / MS. In the antennas of E. cyparissias (♂ and ♀), sensilla types were identified as Böhm's bristles, squamiformia, trichodea, basiconica, chaetica, auricilica, coeloconica, ampullacea. The electrophysiological bioassays indicated in the male wing extract of E. cyparissias the presence of an electrophysiologically active compound, geranylgeraniol that provided the depolarization of antennas of virgin females of the same species. The male (bipectinate) and female (filiform) antennae were found to have sexual dimorphism in A. liberia, the types of sensilla identified were trichodea, chaetica, basiconica, coeloconica, squamiformia, styloconica and Böhm's bristles. The pheromone producing gland in A. liberia was identified on the intersegmental membrane between the last abdominal segments and histological study suggests the presence of glandular cell. The electrophysiological analysis shows that the extract of the sexual gland of A. liberia causes depolarization of the antenna of virgin males suggesting that the female extract has an electrophysiologically active composition. In E. cyparissias, a component that stimulates the antennae of the coespecific insects of the opposite sex of this species was identified while A. liberia presented the extract of the sex gland of electrophysiologically active virgin females for males, this information is relevant and may outline future perspectives for chemical ecology of these species with the intention of alternative control.