Effect of α-cypermethrin and pirimiphos-methyl on wing morphology of Tribolium castaneum (Herbst) and T. confusum Jacquelin du Val: a comparative study

Tribolium castaneum (Herbst) and Tribolium confusum Jacquelin du Val (Coleoptera: Tenebrionidae) are widespread and serious pests of stored products. Various insecticides are applied aiming to effectively manage both species. Here, two insecticides are tested, the pyrethroid alpha-cypermethrin and the organophosphate pirimiphos-methyl, hypothesizing that they can lead to morphological changes in the certain body parts of the adult offspring of treated T. castaneum and T. confusum parental female adults. For this purpose, the geometric morphometric method to the elytra and hindwings was applied. Both males and females were included in the analysis. The results showed that adult individuals of T. confusum showed higher tolerance to both insecticides compared to T. castaneum adults. This finding is reflected in analyses of both pairs of wings in T. confusum where changes in shape were negligible. The hindwings of T. castaneum experienced deformations to both insecticides. More significant changes in wing shape were observed in the alpha-cypermethrin treatment compared to pirimiphos-methyl. In the case of T. castaneum, even the shortest exposure to insecticides (5 min) is enough to provoke shape changes in the hindwings. Deformities in offspring, caused after treatment of their parents with insecticides, could moderate the frequency of insecticidal applications in storages.

Automated summary

This study investigated the morphological changes in the adult offspring of T. castaneum and T. confusum after exposure to two insecticides. Results showed that T. confusum had higher tolerance to the insecticides compared to T. castaneum. The hindwings of T. castaneum experienced deformations, with more significant changes observed in the alpha-cypermethrin treatment. The findings suggest that deformities caused by insecticide exposure in parental adults could reduce the frequency of insecticidal applications in storage facilities.