Hyperaspis polita Weise functional response: effects of predator stages, prey species, and previous feeding experiences

Abstract

At the moment, Hyperaspis polita Weise is a key predator of mealybugs in southern Iran. In this study, the efficiency of this predator on Phenacoccus solenopsis Tinsley, a serious pest, and Planococcus citri Risso as a factitious prey in predator mass rearing, was examined. The functional response experiment was performed for 4th instar larvae, adult male and female of H. polita at five prey densities (2, 4, 8, 12, 16, and 32 adult female stage) on these two preys. The shape of functional response curves well fitted the type II for 4th instar larvae, adult male and female of H. polita on both preys, whenever reared on one prey, while being exposed to the other prey (previous feeding experiences). Comparisons of attack rates and handling time for 4th instar larvae and adult female did not show any difference for various preys as well as previous feeding experiences. For the adult male, when reared on P. solenopsis, the handling time was significantly longer, while it was shorter on P. citri and again the same prey was given to it. The predation was highest for the 4th instar larva followed by adult females and adult male on all treatments. In addition, the maximum predation rate was shown when these predators were reared on P. solenopsis and were exposed to P. citri. The results of this study indicated that H. polita can be an effective biological control agent for mealybugs. It also emphasizes the importance of previous feeding experiences in release program protocols for H. polita.