Local habitat type influences bumble bee pathogen loads and bee species distribution
Data files
Apr 17, 2023 version files 2.41 GB
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Grattonetal_localhabitat_bumblebees_data_code.zip
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README.csv
Abstract
Bumble bees (Bombus spp.) perform important ecological services in both managed and natural ecosystems. Anthropogenically-induced change, however, has altered the availability of floral resources, climatic suitability, and exposure to insecticides, factors that impact overall health and disease levels in these bees. Habitat management presents a solution for improving bee health and biodiversity, but this requires better understanding of how different pathogens and bee species respond to habitat conditions. Herein, we take advantage of the washboard of repeated ridges (forested) and valleys (mostly unforested and developed) in central Pennsylvania to examine whether local variation in habitat type and other landscape factors influence bumble bee community composition and the levels of four leading pathogens in the common eastern bumble bee, Bombus impatiens. Loads of viral pathogens (deformed wing virus and black queen cell virus) were found to be lowest in forest habitats, whereas loads of a gut parasite, Crithidia bombi, were highest in forests. Ridgetop forests hosted the most diverse bumble bee communities, including several habitat specialists. B. impatiens was most abundant in valleys, and showed higher incidence in areas of greater disturbance, including more developed, unforested, and lower floral resource sites, a pattern that mirrors its success in the face of anthropogenic change. Additionally, DNA barcoding revealed that B. sandersoni is much more common than is apparent from databases, likely due to misidentification as mimics B. perplexus and B. vagans. Our results provide evidence that habitat type can play a large role in pathogen load dynamics, but in ways that differ by pathogen type, and point to a need for consideration of habitat at both macro-ecological and local spatial scale