Background-dependentWolbachia-mediated insecticide resistance inLaodelphax striatellus

摘要

Although facultative endosymbionts are now known to protect insect hosts against pathogens and parasitoids, the effects of endosymbionts on insecticide resistance are still unclear. Here we show thatWolbachiaare associated with increased resistance to the commonly used insecticide, buprofezin, in the small brown planthopper (Laodelphax striatellus) in some genetic backgrounds while having no effect in other backgrounds. In threeWolbachia-infected lines from experimental buprofezin-resistant strains and one line from a buprofezin-susceptible line established from Chuxiong, Yunnan province, China, susceptibility to buprofezin increased after removal ofWolbachia. An increase in susceptibility was also evident in aWolbachia-infected line established from a field population in Rugao, Jiangsu province. However, no increase was evident in two field populations from Nanjing and Fengxian, Jiangsu province, China. WhenWolbachiawas introgressed into different genetic backgrounds, followed byWolbachiaremoval, the data pointed toWolbachiaeffects that depend on the nuclear background as well as on theWolbachiastrain. However, there was no relationship betweenWolbachiadensity and the component of buprofezin resistance associated with the symbiont. The results suggest thatWolbachiaeffects associated with chemical resistance are complex and unpredictable, but also that they can be substantial.