Response of Wollastoniella rotunda (Hemiptera: Anthocoridae) to volatiles from eggplants infested with its prey Thrips palmi and Tetranychus kanzawai: Prey species and density effects

Abstract

The effects of prey species [ Thrips palmi Karny (Thysanoptera: Thripidae) and Tetranychus kanzawai Kishida (Acari: Tetranychidae)] and their densities per plant on the olfactory responses of females of the anthocorid predator Wollastoniella rotunda Yasunaga and Miyamoto (Hemiptera: Anthocoridae) to volatiles from plants that were either intact or infested by prey were investigated using a Y-tube olfactometer. W. rotunda females preferred the volatiles from intact eggplants ( Solamum melongena) to clean air. The females preferred volatiles from eggplants infested with either of the two prey species at different densities (200 and 800 female prey species) over intact eggplant volatiles. The females also preferred volatiles from plants infested with 800 females to those from plants infested by 200 females of the same species. W. rotunda females preferred the odor from eggplants infested with 200 T. kanzawai to that from eggplants infested with 200 T. palmi. When the number of prey per plant was increased to 800, the predators showed equal preference for eggplants infested by either of the two prey species. W. rotunda females preferred the odor from the eggplants infested with 800 T. palmi to that from the eggplants infested with 200 T. kanzawai, and the odor from eggplants infested with 800 T. kanzawai to that from eggplants infested with 200 T. palmi. The preferences of W. rotunda for infested eggplants were discussed from the viewpoints of using this predator for the biological control of T. palmi and T. kanzawai.