Pesticide stress induces spermatozoa DNA damage and morphological abnormalities in Apis mellifera populations

The rising losses of honey bee colonies are causing public concern regarding the species' long-term sustainability. Therefore, this study aimed to assess how pesticide exposure affects DNA damage and morphological traits of drone spermatozoa across different Apis mellifera populations, categorized by varying colony loss rates. Chromatographic analysis identified 24 pesticide residues in bee samples and colony food stocks. Significant differences were found in comet assay parameters (tail intensity and Olive tail moment), frequency of morphological abnormalities, and morphometric variations in spermatozoa between apiaries experiencing high versus low mortality rates. The findings indicate that DNA damage and morphological abnormalities in spermatozoa, potentially caused by pesticide stress, compromise the reproductive ability of honey bee drones, contributing to the complex phenomenon of colony loss. The comet assay parameters and morphological aberrations of honey bee spermatozoa may serve as effective biomarkers for evaluating the fitness of drone spermatozoa and assessing environmental hazards to bee populations.