Voláteis da bananeira com efeitos adjunvantes ao feromônio de agregação sintético Sordidina para manejo e controle de Cosmopolites sordidus Germar, 1823 Coleoptera: Curculionidae

Abstract

Cosmopolites sordidus (Germar, 1823) (Coleoptera: Curculionidae), known as banana weevil, it is considered a key banana pest, causing damage to both the pseudostem and the rhizome of the plant. To control it, the use of attractive baits is recommended, so the use of semiochemicals has proven to be an efficient alternative. Studies indicate that the use of synthetic pheromones, isolated or in mixtures, has demonstrated attractiveness for some species of coleoptera. Therefore, the work aims to improve the performance of the synthetic pheromone Sordidine in the control of banana moth with the addtion of kairomones from the host plant with adjuvants in its formulation to considerably reduce costs in product formulation. The pseudostem was collected without damage caused by C. sordidus and stored in B.O.D. at room temperature for fermentation. Fermentation periods were 15 and 30 days, in addition to tests with fresh pseudostem. Volatiles from fresh and fermented banana pseudostem were obtained using the dynamic headspace technique. The extracts obtained were analyzed and the compounds were identified using Gas Chromatography coupled to Flame Ionization Detector (GC-FID) and Gas Chromatography coupled to Mass Spectrometry (GC-MS). To identify electrophysiologically active compounds, analysis was carried out using Gas Chromatography coupled to Electroantenography (GC-EAG). In bioassays in a Y olfactometer, the behavioral response of C. sordidus adults to dynamic headspace extracts of pseudostems was observed. Theaspirane, a compound found and identified in senescent banana leaves, was added to the work. Chemical analyzes of headspace extracts revealed the presence of a total of 21 compounds subdivided into the three phases of pseudostem fermentation. (fresh and fermented for 15 and 30 days), showing that at least four compounds were present in the three fermentation phases. In electroantenography bioassays (GC-EAG), two compounds present in the headspace and theaspiran were active for C. sordidus females. The pseudostem fermented for 15 days releases a greater quantity of volatile compounds, with the majority being the compounds (E)-β-ocimene and hexadecanal. The compounds (Z)-β- ocimene, tetradecanal and theaspirane are active for C. sordidus females. The volatile compounds released by the host plant elicit attraction behavior for males and females of C. sordidus. The theaspirane+tetradecanal and (Z)-β ocimene+tetradecanal+theaspirane mixtures trigger an attractive response for males and females.

Keywords: Musa spp; Behavioral Control; Semiochemicals; Banana weevil