Sublethal emamectin benzoate suppresses multi-transgenerational reproduction and alters bacterial community composition of Thrips tabaci

Abstract

Thrips tabaci (Thysanoptera: Thripidae) is a globally significant agricultural pest whose control relies heavily on insecticides. This study comprehensively assessed the toxicity and sublethal effects of emamectin benzoate (EB) against T. tabaci and explored its underlying mechanisms. EB exhibited high acute toxicity, and at the LC20 level, it significantly reduced longevity and fecundity in the F0 generation, with these inhibitory effects persisting into the F1 generation. Molecular analyses revealed that the P450 gene CYP6K1 is crucial in the T. tabaci’s response to insecticide stress, and RNAi-mediated suppression of CYP6K1 expression significantly increased susceptibility. Additionally, sublethal dose EB exposure altered the gut microbiota, marked by a decline in Acinetobacter and an expansion of Pantoea. We suggest that T. tabaci may mounts a coordinated defense associated with both the host CYP6K1 gene and intestinal symbionts, and disruption of this system may be linked to impair tolerance. These findings provide multi-level insights into the effect of EB on T. tabaci, supporting the development of integrated management strategies targeting both host detoxification and microbial communities.