Functional response of Amblyseius largoensis to Raoiella indica eggs is mediated by previous feeding experience

Abstract

The mechanisms involved in the acceptance and choice of prey by predatory mites are still poorly understood. The present study was designed to determine whether previous feeding experience of Amblyseius largoensis (Muma) (Acari: Phytoseiidae) on Raoiella indica Hirst (Acari: Tenuipalpidae) eggs could influence the predator’s functional response and related parameters. The consumption of R. indica eggs by experienced and naïve female A. largoensis was evaluated under increasing densities of eggs. Regardless of the predators’ previous experience, a gradual increase in the number of eggs consumed and a tendency to stabilize at higher densities were observed. Proportionally, egg consumption decreased with increasing egg densities, indicating a type II functional response for both experienced and naïve predators. Experienced and naïve predators also had the same attack rate. However, naïve predators had a handling time almost 50% longer than experienced predators and showed lower variation in egg consumption and lower peak egg consumption. The results of the present study demonstrate that previous feeding experience may alter parameters of the functional response of A. largoensis to R. indica eggs but not the type of response. Possibly, longer associations between native populations of A. largoensis and R. indica results in more aggressive predator populations.