Functional response and fecundity of a native Neoseiulus californicus population to Tetranychus urticae (Acari: Phytoseiidae, Tetranychidae) at extreme humidity conditions

Amblyseis swirskii (Acari: Phytoseiidae) is the most abundant predatory mite in commercial citrus orchards in Adana province (Turkey), in spite of heavy acaricide and insecticide applications. In this study, the non-target effects of commonly used acaricides in those citrus orchards that follows abamectin, etoxazole, spirdiclofen, spirotetramat, and pyridaben against different developmental stages of A. swirskii were determined by laboratory-based bioassays. Among the acaricides, abamectin and pyridaben were found to be toxic to all developmental stages of the predator as their applications resulted in 36.00 and 27.5%, 84.00 and 86.66%, 21.66 and 95.00% mortalities in eggs, larvae, and adult females, respectively. Similarly fecundity was the highest in the control group (2.65 mean/female/day). In contrast, a dramatic decrease was observed following pyridaben application (0.35 mean/female/day), whereas abamectin has intermediate effects (1.24 mean/female/day), at 120 h. The rest three acaricides are neither toxic to all developmental stages nor fecundity of the predator, as they resulted in less than 10% mortality even for the larvae which was the most sensitive life stage to the other two acaricides. In conclusion, etoxazole, spirodiclofen, and spirotetramat may be compatible in citrus orchards or other agricultural systems where A. swirskii is an abundant predator.