Toxicological assessment of a novel spiro‐derivative, 4‐amino‐1‐azaspiro[4.5]dec‐3‐en‐2‐one for the greater wax moth, Galleria mellonella

Abstract

The greater wax moth, Galleria mellonella L., poses a substantial threat to apiculture, adversely impacting wax quality and potentially acting as a disease vector. There is an urgent need to develop innovative and effective control strategies to address the challenges posed by this pest and ensure the sustainability of the apiculture industry. Spiro‐derivative compounds represent a novel class of environmentally safe compounds with high insecticidal properties. For example, they have demonstrated high efficacy against sap‐sucking insects such as aphids and whiteflies. However, their effect on chewing insects has not yet been well explored. In this study, we hypothesized that 4‐amino‐1‐azaspiro[4.5]dec‐3‐en‐2‐one (4A1AD), a spiro‐derivative compound, would exhibit efficacy against G. mellonella larvae. To test this hypothesis, we conducted dipping and feeding bioassays, incorporating varying concentrations of 4A1AD on fourth instar G. mellonella larvae, and recorded mortality, biochemical parameters including total soluble protein content and enzyme activities, and anatomical abnormalities resulting from treatment. Results revealed a significant increase in larval mortality with increased concentrations and treatment durations across both bioassays. Additionally, a significant decrease in protein content and an increase in phenol‐oxidase activity were observed with alterations in α and β‐esterase activities. Scanning electron microscope findings revealed abnormalities in larval cuticle, spiracular openings and legs. These findings demonstrated the efficacy of 4A1AD, indicating a potential alternative to conventional insecticides in promoting sustainable apiculture practices. Moreover, they provide valuable contributions to the development of novel strategies for effective pest management in apicultural settings.