[Pollinator] Honey bee hives decrease wild bee abundance, species richness, and fruit count on farms regardless of wildflower strips

[David Inouye]

Angelella, G. M., et al. (2021). "Honey bee hives decrease wild bee 
abundance, species richness, and fruit count on farms regardless of 
wildflower strips." Sci Rep 11(1): 3202.
     Pollinator refuges such as wildflower strips are planted on farms 
with the goals of mitigating wild pollinator declines and promoting crop 
pollination services. It is unclear, however, whether or how these goals 
are impacted by managed honey bee (Apis mellifera L.) hives on farms. We 
examined how wildflower strips and honey bee hives and/or their 
interaction influence wild bee communities and the fruit count of two 
pollinator-dependent crops across 21 farms in the Mid-Atlantic U.S. 
Although wild bee species richness increased with bloom density within 
wildflower strips, populations did not differ significantly between 
farms with and without them whereas fruit counts in both crops increased 
on farms with wildflower strips during one of 2 years. By contrast, wild 
bee abundance decreased by 48%, species richness by 20%, and strawberry 
fruit count by 18% across all farm with honey bee hives regardless of 
wildflower strip presence, and winter squash fruit count was 
consistently lower on farms with wildflower strips with hives as well. 
This work demonstrates that honey bee hives could detrimentally affect 
fruit count and wild bee populations on farms, and that benefits 
conferred by wildflower strips might not offset these negative impacts. 
Keeping honey bee hives on farms with wildflower strips could reduce 
conservation and pollination services.


-- 
Dr. David W. Inouye
Professor Emeritus
Department of Biology
University of Maryland

Principal Investigator
Rocky Mountain Biological Laboratory