Sublethal emamectin benzoate suppresses multi-transgenerational reproduction and alters symbiotic bacteria of Thrips tabaci

Thrips tabaci (Tysanoptera: Tripidae) 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 LC ₂₀ level, it significantly reduced longevity and fecundity in the F ₀ generation, with these inhibitory effects persisting into the F ₁ 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 propose that T. tabaci mounts a coordinated defense mediated by both the host CYP6K1 gene and intestinal symbionts, and disruption of this system impairs 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.