Functional response of the predatory mite Cydnoseius negevi (Swirski & Amitai) (Acari: Phytoseiidae) to the Oligonychus afrasiaticus (Mcgregor) and Tetranychus urticae Koch (Acari: Tetranychidae

The study of functional response characteristics of natural enemies is one of the most important approaches to assess their efficiency in regulating the pest population as they are key aspects in the dynamics of predator-prey interactions. In the present study, the functional response type and parameters, and maximum feeding capacity of the predatory mite Cydnoseius negevi(Swirski & Amitai) (Acari: Phytoseiidae)deutonymph and adult femalewere assessed at different densities of movable stages of the date palm mite (DPM) Oligonychus afrasiaticus(McGregor) and two-spotted spider mite (TSSM)Tetranychus urticaeKoch(Acari: Tetranychidae). The experiments were carried out at30 ± 2°C andrelatively low humidity of35 ± 5 % RH under controlled conditions, for the first time. The logistic regression model was used to determine the type of functional response exhibited by C. negevi.Both the stages of predator showed Type II functional response when fed the DPM and TSSM individuals at different stages.Roger’s random-predator equationwas used to define the handling time (Th) and attack rate (a) coefficients of type II functional response by fitting the equation into the non-linear least square regression model.The longest Thwas shown by deutonymph andadult females of C. negeviwhen they fed on the DPM and TSSM females, and TSSM females, respectively. Furthermore, no significant differences were recorded for most of the avalues of the deutonymph and adult female of C. negeviamong different stages of DPM and TSSM. The maximum feeding capacity of C. negeviadult female was significantly higher for DPM female when compared with that of TSSM. According to previous and current studies, C. negevicould be a potential predator at a wide range of humidity.