The influence of learning behavior on the predation of Tetranychus turkestani by Nesoseiulus bicaudus

Neoseiulus bicaudus Wainstein (Acari: Phytoseiidae), an important natural enemy of spider mites, is commonly reared on Tyrophagus putrescentiae Schrank (Acari: Acaridae) as a food source. As learning behavior enhances insect foraging efficiency, this study investigated the effects of learning behavior on the predation of Tetranychus turkestani Ugarov et Nikolskii (Acari: Tetranychidae) by N. bicaudus, by evaluating the effects of learning frequency and reward status on olfactory response and memory retention. The influence of learning experiences at different developmental stages on predation capacity as adults was also assessed, alongside the effect of learning behavior on control efficacy against Te. turkestani. Results showed that 4-nonreward learning enabled N. bicaudus to form memories lasting 0.5 h with olfactory behavioral changes, while 4-reward learning induced stable memory persisting 72 h and a significant olfactory preference for Te. Turkestani. This preference lasted at least 0.5 h and was not induced by nonreward learning. Learning experiences during the larval, deutonymphal, and female adult stages significantly increased the attack rate and prey handling time of female N. bicaudus. Among these groups, the female adult learning and larval learning groups showed the most significant predation efficiency, with maximum daily consumption of 17.54 and 19.61 prey individuals, respectively. Field trials confirmed that N. bicaudus trained through learning exhibited enhanced biological control efficacy. In conclusion, incorporating targeted learning into large-scale rearing enhances N. bicaudus's sensitivity to target prey, thereby improving biological control efficacy.