Influence of Soybean Cultivar Resistance on the Foraging Behavior of Encarsia sp. Against Bemisia tabaci MEAM1

Abstract

Bemisia tabaci MEAM1 is a significant pest in soybean crops, posing a challenge for control and requiring novel strategies within Integrated Pest Management (IPM). This study evaluated the host-searching behavior of the parasitoid Encarsia sp. in response to volatiles emitted by soybean cultivars infested with B. tabaci. Using a Y-shaped olfactometer, we tested the cultivars BRASMAX BÔNUS IPRO® (susceptible) and M 8808 IPRO® (resistant by antixenosis), assessing the parasitoid's response to the emitted volatiles. Additionally, we conducted behavioral bioassays to evaluate Encarsia sp. exploration on leaf disks of the infested cultivars. The results showed that the parasitoid spent more time in the central region of the olfactometer, with no clear preference between cultivars. However, in the foraging bioassays, Encarsia sp. explored the susceptible cultivar more actively, demonstrating a higher frequency of interactions such as antennation and attack on nymphs. The resistant cultivar exhibited lower behavioral diversity, suggesting reduced chemical or physical stimulation for the parasitoid. These findings indicate that the intrinsic characteristics of soybean cultivars can enhance the effectiveness of biological control and constitute a key factor in IPM strategies aimed at optimizing parasitoid performance in whitefly control.