Food preference of Amblyseius swirskii (Acari: Phytoseiidae) on different stages of Tetranychus urticae (Acari: Tetranychidae) and Bemisia tabaci (Hemiptera: Aleyrodidae)

Abstract

The prey preference of polyphagous predators plays an important role in suppressing different species of herbivorous mites and insects. Prey stages preference of the predatory mite, Amblyseius swirskii Athias-Henriot was investigated among egg, protonymph and deutonymph of Tetranychus urticae Koch and egg, first and second instar nymphs of Bemisia tabaci Gennadius. All experiments were conducted using bean (cultivar: Almoti) leaf discs in Petri dishes (8 cm in diameter) under laboratory condition with 25±2 C, 70±5% RH and 16 L: 8 D photoperiod. The preference for female predator was calculated with Manly’s preference index ( β ). Comparison of the preference indices using a t-test showed that A. swirskii consumed significantly more eggs than protonymphs and deutonymphs of T. urticae . There was also a significant difference between consumed protonymphs and deutonymphs of T. urticae . A. swirskii consumed significantly more eggs than second instar nymphs of B. tabaci . There was a significant difference between first instar nymphs and second instar nymphs of B. tabaci and between eggs and first instar nymphs of B. tabaci . Our findings suggest that prey stages had effect on the prey selection of A. swirskii .