Intraspecific variation in the olfactory response of the predatory mite Neoseiulus womersleyi Schicha (Acari: Phytoseiidae) to different amount of spider mite-infested plant volatiles

Abstract

We investigated the olfactory responses of six strains of the predatory mite Neoseiulus womersleyi Shicha to different amounts of volatiles of Tetranychus urticae Koch-infested kidney bean plants. Four strains of the predators were collected from different sites in Japan (i.e., 4 geographical populations). The other two strains were inbred lines bidirectionally selected from a base population for their olfactory responses. All strains showed significantly higher olfactory preferences for the volatiles of 15 plants than those for 5 plants. We found a significant correlation between preferences for 15 plants and those for 5 plants. The olfactory preferences for spider mite-infested plant volatiles differed significantly among strains. The olfactory preferences of the 2 inbred strains were significantly different. These results suggest that the variation among local populations may result from genetic differences in sensitivity to spider mite-induced plant volatiles.