Predatory Capacity and Feeding Preference of Pesticide-Resistant Amblyseius deleoni Muma et Denmark (Mesostigmata: Phytoseiidae)

The population of the predatory mites Amblyseius deleoni had been decreasing due to continuous use of synthetic pesticides in tea plantations. Therefore, this study aimed to select pesticide-resistant individuals from a wild-type population of A. deleoni and to evaluate whether or not the resistant A. deleoni were still sensible as biological control agents.  We exposed A. deleoni to (propargite), fungicide (copper oxide) and a neem seed extracts. We found that the propargite-resistant predatory mites consumed larvae and nymphs of Tetranychus urticae more than the control (wild type) (P 0.05). The number of individuals of every stage of T. urticae consumed by copper-oxide resistant A. deleoni was the same (P > 0.05).  In general, there were no changes in food preference in the resistant predators to the 3 of pesticides (P > 0.05). There were slight differences on the pattern of predatory capacity among the resistant predators to the three pesticides.  Although the predators are resistant to the 3 pesticides, it took longer to consume their prey in comparison to the control.  These findings suggested that pesticide-resistant A. deleoni were able to maintain their functions as a biocontrol agent. HIGHLIGHTS The effectiveness of Amblyseius deleoni as a natural predators have decreased due to continuous uses of synthetic pesticides to control pests and diseases on tea plantations Continuous exposure to propargite, CuO and neem seed extracts induced the predatory mites deleoni to develop resistance No significant changes in feeding preference and the predatory capacity of the mite deleoni on T. urticae after becoming resistant to pesticides Exposures deleoni to pesticides may have induced heritable epigenetic changes permanently or just reversible phenotypes without changing the DNA sequence