Innate and acquired response of Neoseiulus barkeri and N. californicus (Acari: Phytoseiidae) to spider mite induced plant volatiles

Predators may adjust their foraging behavior according to herbivore-induced plant volatiles innately or through learning. we investigated whether the phytoseiid predatory mites, neoseiulus barkeri and n. californicus, exhibited an innate ability to respond to odors of tetranychus urticae-infested bean leaves. naïve female mites were reared on washed t. urticae as prey on filter paper with no prior exposure to spider mite-induced plant volatiles (sipv). the olfactory experiments showed that significantly more n. barkeri and n. californicus moved towards t. urticae-infested bean leaves compared to clean air. neoseiulus californicus significant preference of t. urticae-infested bean leaves rather than clean tomato (as unfamiliar environment) confirmed the innate response in this species, while n. barkeri could not differentiate the latter odor sources, suggesting a weak innate response. in a separate set of experiments, naïve n. californicus females with no preference towards hipv were experienced by receiving odors related to t. urticae-infested bean leaves. the changed response (significant preference) of the experienced individuals showed the predators ability for acquired response. as the predator paired the odor with food absence/presence, associative learning was suggested as the mechanism. no acquired response was recorded for n. barkeri.