Vespa social Polybia fastidiosuscula: resposta olfativa para voláteis e identificação dos compostos de plantas de milho induzido

Abstract

The caterpillar Spodoptera frugiperda (Smith, 1797) (Lepdopitera: Noctuidae) is a pest in corn, affecting up to 60%, the grain yield. One way to control this pest is through biological control, and predatory wasps a viable alternative. Thus, we aimed to evaluate the olfactory response of the social wasp Polybia fastidiosuscula (Saussure) (Hymenoptera: Vespidae) to volatiles released by maize plants and / or caterpillar S. frugiperda. Using a olfactometer-Y, behavioral experiments were conducted to verify the behavioral response to volatile social wasps released by S. frugiperda larvae by corn plants, induced by corn plants with caterpillars Spodoptera frugiperda and corn plants mechanical injuries and / or treated with caterpillars regurgitate or water. It was observed that the wasps did not have significant social preferably when offered up, air, caterpillars, corn plants without induction or mechanically injured maize plants treated with water. However, wasps preferred induced by S. frugiperda larvae or mechanically injured plants treated with caterpillars of regurgitation during intervals 5-6 hours and 24-25 hours plants. The same was not observed when plants were induced by caterpillars or injured mechanically treated with caterpillar regurgitate in the range of 1-2 hours. These results were confirmed when offered up corn plant extracts induced by S. frugiperda larvae or corn plants injured overflow, mechanically treated larvae after 5-6 hours of induction versus hexane as control. In a second phase extracts of corn plants without induction, corn plants with the presence of S. frugiperda for 1 hour, corn plants with the continued presence of S. frugiperda and corn plants injured mechanically treated regurgitate Crawler were quantified by gas chromatography-flame ionization detection (GC-FID) and analyzed by gas chromatography coupled to mass spectrometry (GC-MS) using helium as the carrier gas. Data were collected and evaluated with the ChemStation software. And the identification of compounds of extracts of maize plants was made by comparison of retention times in GC-FID with patterns using nonpolar column and Kovats index calculation.