Non-choice vs. Free-choice: when and how Cydnoseius negevi (Swirski and Amitai) female attack its prey?

Abstract

Background Cydnoseius negevi (Swirski and Amitai) (Acari: Phytoseiidae) is a promising bio-agent in the Mediterranean region. It attacks a wide range of pest species. Two fundamental questions have been raised when C. negevi was a promising candidate for biological control applications in a hydroponic system. This study was carried out to answer the raised questions: (1) how long a predatory female takes to attack its prey in a non-choice biological control application? and (2) what do the predatory females prefer when offered a multiple choice (free-choice) of pest preys?, to understand the potentialities of C. negevi attacking behaviour. Results Two sets of experiments were conducted for 240 min under laboratory conditions of 27 ± 2 °C, 60 ± 5% RH, and 18:6h L:D photoperiod. The tested prey species were Tetranychus urticae Koch, Bemisia tabaci (Gennadius), Frankliniella occidentalis (Pergande), Parlatoria ziziphi (Lucas), and Icerya aegyptiaca (Douglas). Non-choice experiments tested the time (min) needed to the 24 h starved female to attack its prey. The free-choice experiments tested the female’ choices and the time recorded for each female during the full experimental time. Significant differences were recorded in both sets at confidence level of 95%. The spider mite T. urticae recorded the shortest predatory female’s response in both non- and free-choice sets. On the contrary, the insect I. aegyptiaca had the least female’s choice in both sets of experiment. Conclusion The present study discussed the behavioural categories of C. negevi. The female responses showed a list of priorities to the tested herbivore species. Such behavioural simulation is considerable for the future pest control applications to predict the generalist predator’s preferences among a wide range of multiple herbivore species.