Learning behavior of Neoseiulus californicus (Acari: Phytoseiidae) can help in adapting from feeding on alternative prey to target prey

Abstract

Neoseiulus californicus (Acari: Phytoseiidae) is a commercialized predatory mite that is used as a biological control agent against Tetranychus urticae (Acari: Tetranychidae). Long-term feeding on alternative prey could impact the predatory capacity of N. californicus. Although most studies on the learning behavior of predatory mites have indicated that learning behavior could help them adapt from feeding on thrips (alternative prey) to spider mites (target prey), the role of learning behavior in adapting from feeding on astigmatid mites to spider mites has not been studied thus far. Therefore, this study explored the learning behavior of N. californicus in adapting from feeding on alternative prey (Oulenziella bakeri [Acari: Winterschmidtiidae]) to target mites (T. urticae). The attack latencies, prey preferences, and functional responses of female N. californicus were compared between two strains, N. californicus fed on T. urticae (TU) or O. bakeri (OB), and a learning behavior (LB) treatment. The results showed that the attack latency of OB strain was significantly longer than those of TU strain and LB treatment; OB strain did not show obvious prey preference between protonymphs of T. urticae and O. bakeri; and the functional response among TU, OB, and LB-treated strains were not significantly different. Our results demonstrated that long-term feeding on alternative prey had little effect on the predatory ability of N. californicus. To a certain extent, learning behavior can help N. californicus shift from feeding on alternative prey to target prey. Therefore, in the long run, it is reasonable to rear N. californicus on O. bakeri.