Abstract
The South American tomato pinworm, Tuta absoluta (Meyrick), is among the most destructive invasive pests of tomato globally. The diamide insecticide tetraniliprole is increasingly used for its management. This study examines the sublethal effects of tetraniliprole on T. absoluta larvae, with a focus on its transgenerational impacts. Bioassays demonstrated that tetraniliprole was highly toxic to third-instar T. absoluta larvae, with an LC(50) of 0.029 mg/L. Sublethal (LC(10)) and low lethal concentrations (LC(30)) were used to investigate their impact on developmental, reproductive, and population parameters across two subsequent generations (F(1) and F(2)). In the parental (F(0)) generation, exposure to tetraniliprole at both concentrations significantly prolonged larval and pupal durations and reduced adult longevity and fecundity. In both F(1) and F(2) generations, concentration-dependent effects were observed-LC(10) accelerated development and enhanced fecundity and population growth, indicative of a hormetic response, whereas LC(30) delayed development and suppressed reproduction and survival. Life table analyses revealed significant changes in the r, λ, and T, particularly under LC(30). Additionally, the RT-qPCR analysis revealed the downregulation of development and reproduction-related genes (Vg, VgR, and JHBP) in the F(0) generation following exposure to tetraniliprole (LC(10) and LC(30)). In contrast, these genes were upregulated in the progeny generations (F(1) and F(2)) at LC(10). Furthermore, the overexpression of key detoxification genes, particularly CYP4M116 and CYP6AW1, persisted across all three generations. Taken together, these findings reveal a substantial risk of unintended population resurgence (hormesis effects) at sublethal concentrations, underscoring the importance of integrating transgenerational consequences into insecticide resistance management programs for sustainable control of this key insect pest.