Feeding efficiency and preference of field collected and lab reared Cydnoseius negevi (Swirski & Amitai) (Acari: Phytoseiidae) against larvae and nymphs of the date palm mite, Oligonychus afrasiaticus (McGregor) (Acari: Tetranychidae)

Abstract: The predatory mite, Cydnoseius negevi (Acari: Phytoseiidae), is naturally associated with the date palm mite (DPM), Oligonychus afrasiaticus (Acari: Tetranychidae), in date palm agroecosystems in Saudi Arabia. A study was conducted to evaluate the feeding efficiency and preference of two different populations (field collected and lab reared) of C. negevi against larvae and nymphs of O. afrasiaticus in the laboratory under low humidity. Larvae and nymphs of DPM together with 50:50 ratios were offered with and without date palm pollen to both populations of the predator. The results indicate that feeding/predation efficiency of field collected and lab reared populations of C. negevi was not significantly different both in presence and absence of date palm pollen as a feed after 3, 6 and 24 hours of predator release (pollen effect feeding efficiency test). In addition, no significant effect of date palm pollen on feeding preference was found in both populations of predator against larvae and nymphs of DPM (prey stage preference test). Both populations of the predator consumed an average of 20-24 immatures (larvae and nymphs) of date palm mite in 24 hours, either offered with or without pollen. It was concluded that rearing of C. negevi on date palm pollen for a long time in the laboratory does not affect the efficiency and feeding preference of the predator against larvae and nymphs of the date palm mite. This indicates that C. negevi could effectively be reared on date palm pollen for mass field release without losing its predation efficiency.