Non-destructive solvent-soaking extraction enables rapid pesticide screening while preserving honey bee specimens

Pesticide residue analysis in honey bees is important for environmental monitoring and pollinator risk assessment. Conventional residue analysis typically relies on whole-body grinding destructive extraction (DE), which enables comprehensive residue recovery but prevents further use of specimens for ecological or morphological analyses. In this study, we evaluated an ethanol-soaking non-destructive extraction (NDE) method as a practical screening approach for pesticide residues in honey bees. Worker bees (Apis mellifera L.) were topically exposed to mixtures containing 25 commonly used pesticides, after which residues were analyzed using both ethanol-soaking NDE and conventional whole-body grinding DE. Although NDE recovered lower absolute residue levels than DE, the two methods showed agreement in pesticide detection patterns. Residue levels obtained by NDE and DE were positively correlated (R² = 0.5917, p = 0.0001), and the relative ranking of pesticide residues across samples was generally consistent between methods (Spearman's r = 0.6459, p = 0.0082). The overlap in detected pesticide compounds was higher shortly after exposure but declined over time, suggesting reduced NDE sensitivity as residues become less accessible, are redistributed, or undergo degradation/metabolism after exposure. These findings suggest that ethanol-soaking NDE may serve as a non-destructive proxy for screening relative pesticide contamination patterns, particularly when specimen preservation is required. However, because this validation was based on topical exposure, further studies are needed to evaluate its performance for orally ingested and internally accumulated residues.