The Effects of DMPF on Honey Bee Pathophysiology

Abstract

Varroa destructor is a parasitic mite that is the leading cause of honey bee colony loss in the United States. To mitigate these losses, beekeepers apply acaricide treatments. N-(2,4-dimethylphenyl) formamide (DMPF), the active metabolite in amitraz, was the highest detected pesticide in the 2017 US National Honey Bee Survey (NHBS), where samples of bees and wax were taken from 300 different apiaries across the United States. Although amitraz is relatively non-toxic to bees, very little is known about its effects on honey bee physiology, which has shown to be a useful tool in predicting overall colony health. This study investigates the potential effects of DMPF in adult honey bees across 19 pathophysiological traits. Samples of adult bees were necropsied from colonies with known levels of DMPF in the comb wax and compared to bees from colonies with no DMPF detections. The statistical results indicate potential associations between physiological symptoms in honey bee organs such as the ventriculus, Malpighian tubules, rectum, sting gland, and venom sac to varying DMPF concentrations. These findings serve to identify preliminary evidence for future work quantifying the overall effects of DMPF on colony health.