Effect of variation in plant-emitted volatiles on the infestation behavior of Tetranychus urticae (Acari: Tetranychidae) and Frankliniella occidentalis (Thysanoptera: Thripidae) in strawberry crops

Abstract

The two-spotted spider mite (TSSM), Tetranychus urticae Koch, and the Western flower thrips (WFT), Frankliniella occidentalis (Pergande), are pests commonly found in strawberry crops and pose significant challenges to production. However, the specific dynamics of their interactions with both healthy and infested plants remain poorly understood. In this study, we aimed to investigate the attraction of TSSM and WFT to volatile compounds emitted by healthy plants versus those of plants damaged by either or both species. Plant choice bioassays were conducted under varying conditions, including both healthy and those previously damaged by both TSSM and WFT. Additionally, behavioral tests were carried out using a Y-tube olfactometer, with extracts obtained via dynamic aeration from the plants in different states. The results revealed distinct preferences: TSSM exhibited a strong attraction to both healthy plants and those previously infested by their own specifics, whereas WFT showed a higher preference for healthy plants and those damaged by TSSM. Consistent behaviors were observed in the bioassays conducted with plant extracts. This research sheds light on the intricate interactions between strawberry plants and these pests and offers insights into the probable sequence of attack when both pests are present concurrently. The findings are valuable when implementing management strategies for these two pests in strawberry cultivation, considering the order in which they appear in the crop to help mitigate the damage caused by infestation in a more precise manner and order.

Keywords: Behavior; Chemical communication; Dynamic aeration; Pest; Y-tube olfactometer.