Honey Bee Viruses in Wild Bees: Viral Prevalence, Loads, and Experimental Inoculation.
Evidence of inter-species pathogen transmission from managed to wild bees has sparked concern that emerging diseases could be causing or exacerbating wild bee declines. While some pathogens, like RNA viruses, have been found in pollen and wild bees, the threat these viruses pose to wild bees is largely unknown. Here, we tested 169 bees, representing 4 families and 8 genera, for five common honey bee (Apis mellifera) viruses, finding that more than 80% of wild bees harbored at least one virus. We also quantified virus titers in these bees, providing, for the first time, an assessment of viral load in a broad spectrum of wild bees. Although virus detection was very common, virus levels in the wild bees were minimal-similar to or lower than foraging honey bees and substantially lower than honey bees collected from hives. Furthermore, when we experimentally inoculated adults of two different bee species (Megachile rotundata and Colletes inaequalis) with a mixture of common viruses that is lethal to honey bees, we saw no effect on short term survival. Overall, we found that honey bee RNA viruses can be commonly detected at low levels in many wild bee species, but we found no evidence that these pathogens cause elevated short-term mortality effects. However, more work on these viruses is greatly needed to assess effects on additional bee species and life stages.
Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, United States of America.
Adam G
AG
Dolezal
Department of Biology, University of Iowa, Iowa City, Iowa, United States of America.
Stephen D
SD
Hendrix
Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, United States of America.
Nicole A
NA
Scavo
Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, United States of America.|Department of Plant Pathology and Microbiology, Iowa State University, Ames, Iowa, United States of America.
Jimena
J
Carrillo-Tripp
Department of Natural Resource Ecology and Management, Iowa State University, Ames, Iowa, United States of America.
Mary A
MA
Harris
Department of Entomology, Iowa State University, Ames, Iowa, United States of America.
M Joseph
MJ
Wheelock
Department of Entomology, Iowa State University, Ames, Iowa, United States of America.
Matthew E
ME
O'Neal
Department of Ecology, Evolution, and Organismal Biology, Iowa State University, Ames, Iowa, United States of America.|Department of Entomology, Iowa State University, Ames, Iowa, United States of America.
Amy L
AL
Toth
D000818:Animals; D001516:Bees / Q000145:classification / Q000821:virology*; D016009:Chi-Square Distribution; D005843:Geography; D054884:Host-Pathogen Interactions; D007304:Insect Viruses / Q000145:classification / Q000502:physiology*; D007484:Iowa; D012328:RNA Viruses / Q000145:classification / Q000502:physiology*; D013045:Species Specificity; D019562:Viral Load