The impact of a widely used fungicide on honey bee (Apis mellifera) health

Wednesday, November 16, 2022

11:24 AM – 11:36 AM PT

Location: Vancouver Convention Centre, Meeting Room 119/120

Presenting Author(s)

Adrian L. Fisher II, II

Postdoctoral Research Associate
Arizona State University
Tempe, Arizona

Co-Author(s)

Jordan R. Glass

Ph.D. candidate
Arizona State University
Tempe, Arizona
Nicole S. DesJardins

PhD Candidate
Arizona State University
Tempe, Arizona
CO

Cahit Ozturk

Arizona State University
Tempe, Arizona
Gloria DeGrandi-Hoffman

Supervisory Research Entomologist
USDA-ARS
Tucson, Arizona
BS

Brian H. Smith

Geospatial Academies Co-Facilitator
Arizona State University
Tempe, Arizona
JF

Jennifer H. Fewell

Presidents Professor
Arizona State University
Tempe, Arizona
Jon F. Harrison

Professor
Arizona State University
Tempe, Arizona

The honey bee (Apis mellifera) is essential for crop pollination worldwide. Despite their importance, honey bees and other pollinators face ongoing declines due in part to pesticide exposure in the foraging environment. Honey bees frequently encounter fungicides, in particular, because they are applied to blooming crops. To assess the effects of the widely used fungicide Pristine^® (25.2% boscalid, 12.8% pyraclostrobin) we exposed colonies to concentrations of the fungicide reflecting levels detected in almond orchards. Chronically exposed hives experienced reduced worker populations and increased winter mortality. We also observed elevated rates of pollen foraging and consumption, potentially indicating impaired protein processing. Pristine^® consumption induced several sublethal effects on individual workers including precocious foraging, reduced longevity, reduced cognitive abilities, and lower thorax mass. Adverse effects of fungicide exposure also resulted from reduced exposure durations simulating the bloom period of a major bee pollinated crop but with differences in severity by season. A four-week exposure to the fungicide Pristine^® reduced worker longevity, induced precocious foraging and temporarily reduced colony population levels during summer. Fall exposure was not associated with negative outcomes and coincided with differing colony conditions including reduced brood production and pollen consumption. Together, these findings support the hypothesis that fungicides such as Pristine^® negatively impact honey bee health at least partly by impairing protein digestion. This research was supported by USDA 2017-68004-26322