Does apiary presence increase honey bee pathogen loads in native bees?

Although honey bees provide valuable agricultural ecosystem services, there is growing concern that managed apiaries may result in competition with nearby native bee communities. As honey bees share flower resources with native bees, particularly later in the summer season when they are more likely to utilize native flowers (Carr-Markell et al. 2020), they may expose native bees to pathogens, such as Israeli Acute Paralysis Virus and Deformed Wing Virus (Dolezal et al. 2016); however, the potential negative effects and ubiquitousness of these pathogens in native bee communities is largely unknown. Research on this topic often utilizes apiaries placed near native bee habitat over a short period of time, rather than investigating the effects of long-term apiary presence (Pritchard et al. 2021). This research addresses this knowledge gap by examining the pathogen loads of social Bombus spp. and non-social Melissodes spp. in 10 prairie sites in east-central Illinois, 5 with long-term ( >10 years) apiaries and 5 without. We hypothesized that long-term presence of apiaries near native bee habitat would result in a higher load of these pathogens in our target genera, with Bombus spp. having higher pathogen loads than Melissodes spp. given differences in their sociality. Additionally, we hypothesized that there would be differences in pathogen loads over time, with later season bees having a higher prevalence of pathogens due to increased exposure to honey bee foragers. This research will help to inform native bee conservation efforts and apiary management.