Arsenophonus and Wolbachia-mediated insecticide protection in Nilaparvata lugens

While symbiont infections in invertebrates are widespread, their role in protecting hosts against natural enemies and chemical insecticides remains incompletely understood. Our study investigates the protective effects of Arsenophonus and Wolbachia, either individually or in co-infection, on Nilaparvata lugens against chemical insecticides. Our findings reveal that both Arsenophonus and Wolbachia confer protection against chemical insecticides, including triflumezopyrim, nitenpyram, and dinotefuran. However, these symbionts do not show protective effects against pymetrozine. Wolbachia infection leads to the up-regulation of the glutathione S-transferase (GST) gene GSTm2 and the P450 gene CYP6AY1. Uniquely, co-infection results in the up-regulation of the P450 gene CYP18A1. Furthermore, the stability of the co-infection is not constant, with its frequency decreasing from 93.3 to 73.1% over a nine-generation passage, while single infections remain consistently high (> 95%). Our study suggests that Wolbachia and Arsenophonus, both individually and in co-infection, provide protection against two commonly used chemical insecticides in N. lugens.