Monitoring of insecticide resistance for Apolygus lucorum populations in the apple orchard in China

Apolygus lucorum (Meyer-Dur) (Hemiptera: Miridae) is an important piercing-sucking pest that has been recorded on more than 200 host plants in China. In recent years, its damage to apple trees has become more and more serious, resulting in malformed fruit and even fruit shedding. It is primarily controlled with insecticides. However, the current status of insecticide resistance of A. lucorum in the apple orchard is rarely reported. In this study, we determined the susceptibility of one laboratory population and six geographic field populations of A. lucorum to ten chemical and six botanical insecticides by glass-vial and artificial diet bioassays. The results showed that among the ten chemical insecticides, bifenthrin exhibited the highest toxicity to this pest by glass-vial bioassays than other insecticides, followed by chlorpyrifos, and then one of the neonicotinoid insecticides nitenpyram. In the artificial diet bioassays, the LC50 values of the avermectin insecticides to A. lucorum populations were significantly lower than those of other classes of insecticides, followed by neonicotinoid insecticides. Among six botanical pesticides, veratramine and pyrethrins showed higher toxicity to A. lucorum populations, while rotenone and cnidiadin exhibited poor effects. The results indicated that chlorpyrifos, bifenthrin, avermectin, and emamectin benzoate could be recommended to mix or rotate with botanical pesticides veratramine and pyrethrins in controlling A. lucorum in the apple orchard. Our study would provide valuable information for choosing alternative insecticides and for insecticide resistance management of A. lucorum.