Sublethal and transgenerational effects of tetraniliprole on the tomato pinworm Phthorimaea (=Tuta) absoluta (Lepidoptera: Gelechiidae)

Abstract

Invasive pest species of economic importance often require intensive pesticide use, leading to recurrent problems of pesticide resistance. Such is the case with the tomato pinworm, Phthorimaea (=Tuta) absoluta (Meyrick) (Lepidoptera: Gelechiidae), requiring the use of new insecticidal compounds for their management. Tetraniliprole, a novel insecticide effective against lepidopteran, coleopteran, and dipteran pests, is a potential alternative against the tomato pinworm. This study investigates the sublethal effects of tetraniliprole on the development and reproduction of the parental (F₀) and progeny (F₁) generations of P. absoluta while exploring the underlying mechanisms. Sublethal tetraniliprole exposure extended larval duration and reduced pupation rate, emergence rate, hatchability, and fecundity in both the F₀ and F₁ of P. absoluta. Additionally, the life-table parameters of the F₁ generation were significantly altered, with decreases in net reproductive rate (R₀) and increases in the mean generation time (T), leading to decreases in the intrinsic rate of population growth (r). The relative fitness of F₁ insects exposed to tetraniloprole was reduced compared to unexposed insects (0.63 and 0.49, respectively). Furthermore, the mRNA expression levels of reproduction-related genes such as TaVg and TaVgR were down-regulated in the tetraniliprole-exposed insects. Finally, insect exposure to tetraniloprole increases the activity of the antioxidant enzymes such as glutathione S-transferase (GSTs), catalase (CAT), and superoxide dismutase (SOD). Taken together, these findings suggest that sublethal concentrations of tetraniloprole adversely affect both the development and reproduction of P. absoluta, providing a foundation for optimizing pest control strategies.