Sublethal impact of pirimiphos-methyl and etofenprox on mandible and hindwing morphology in Alphitobius diaperinus

Insecticidal applications can cause morphological deformities to the exposed insects or their offspring. Pirimiphos-methyl and etofenprox have been previously evaluated against Alphitobius diaperinus, but there is no knowledge about their effect on the morphology of the F1 generation. This study examines the effect of both insecticides on mandible and hindwing morphology of A. diaperinus adult progeny. Regarding the shape of the mandibles in both female and male individuals, the two insecticides induced significant deformations compared to the control group. Etofenprox caused more vigorous morphological changes vs. pirimiphos-methyl. In terms of hindwings, Principal Component Analysis (PCA) did not reveal distinction between females or males exposed to either etofenprox or pirimiphos-methyl. Both insecticides affected the mouthparts of the F1 generation adults of A. diaperinus, which could lead to reduced feeding ability and thus to insufficient population growth.