Functional and numerical responses of Cydnoseius negevi (Swirski and Amitai) to three invasive pests

Agricultural system in Egypt represents a promising alternative for addressing water scarcity and land limitations. However, these systems are increasingly affected by invasive pest species including the two-spotted spider mite (TSSM), Tetranychus urticae Koch (Prostigmata: Tetranychidae), the onion thrips, Thrips tabaci Lindeman (Thysanoptera: Thripidae), and the silverleaf whitefly, Bemisia tabaci (Gennadius) (Hemiptera: Aleyrodidae). This study evaluated the functional and numerical responses of the native predatory mite, Cydnoseius negevi (Swirski and Amitai) (Mesostigmata: Phytoseiidae) to different densities of these three invasive pest species under laboratory conditions. Predation assays were conducted using prey densities 1, 5, 10, 20, 40, and 80 individuals. Functional response parameters including attack rate (α) and handling time (Th), were estimated using nonlinear regression, and numerical responses were analysed using generalized linear models using R program. Cydnoseius negevi exhibited a Type II functional response to all prey species. Attack rate and handling time varied significantly among prey species, with the highest predation efficiency observed on T. urticae. A significant positive numerical response was detected for T. urticae and B. tabaci, whereas no significant response was observed for T. tabaci. These results indicate that prey type strongly influences predator performance and suggest that C. negevi has a strong potential as a biological control agent, particularly for T. urticae.