Meeting Abstract

74-6   14:30 - 14:45  Seasonal variability in physiology and behavior affect the impact of fungicide exposure on honey bee (Apis mellifera) health Fisher II, A*; Ozturk, C; Glass, JR; DesJardins, N; DeGrandi-Hoffman, G; Smith, BH; Fewell, JH; Harrison, JF; Arizona State University; Arizona State University; Arizona State University; Arizona State University; USDA-ARS; Arizona State University; Arizona State University; Arizona State University afishe16@asu.edu

The honey bee (Apis mellifera) is an essential contributor to crop pollination worldwide. Despite their importance, honey bees and other pollinators face ongoing declines due in part to pesticide exposure in the foraging environment. In particular, honey bees frequently encounter fungicides due to their widespread application to blooming crops. To assess the effects of the widely used fungicide Pristine® (25.2% boscalid, 12.8% pyraclostrobin) we fed colonies pollen containing varying field-relevant concentrations of Pristine® for a duration reflecting the bloom period of almonds. Exposure occurred in two separate seasons, once in early summer when colonies were growing, and once in late fall when brood-rearing was low. Early summer exposure to the fungicide had negative effects on the age of first foraging, worker longevity and pollen foraging. Colonies fed Pristine®-laced pollen in late fall engaged in precocious foraging but there was no significant effect on worker longevity, pollen collection or consumption. Worker lifespan during winter was substantially longer and brood rearing was reduced likely contributing to the partially muted impact of fungicide exposure due to reduced consumption of fungicide-tainted pollen and reduced foraging activity. This research was supported by USDA 2017-68004-26322.