Four North American bumble bee species in the subgenus Bombus sensu stricto, including Bombus occidentalis (Hymenoptera: Apidae), are experiencing dramatic declines in population abundance, geographic range and genetic diversity. The prevailing hypothesis concerning their decline is the transmission of the intracellular fungal pathogen. Nosema bombi (Microsporida), and other pathogen species from commercially reared bumble bees to wild populations. While N. bombi incidence has been investigated in the contiguous U.S.A. and Canada, virtually nothing is known about the status of Alaskan bumble bees. This study presents the distribution and relative abundance of B. occidentalis and B. moderatus, two co-occurring species in the subgenus Bombus sensu stricto, in Alaska and the prevalence of N. bombi detected in these species. Bombus occidentalis and B. moderatus accounted for 28% and 4% of the 942 bumble bees surveyed, respectively. Bombus occidentalis was the most abundant species collected in the survey and prevalence of N. bombi infections (44% infected) was also highest in this species. The proportion of infected B. moderatus did not differ significantly from other co-occurring bumble bees. Despite the presence of N. bombi infections, both Bombus s. str. species were commonly detected in Alaska with our survey method. Alaskan bumble bee populations may thus provide important insights on the role of pathogens, particularly N. bombi, in bumble bee decline in the contiguous U.S.A.
You have requested a machine translation of selected content from our databases. This functionality is provided solely for your convenience and is in no way intended to replace human translation. Neither BioOne nor the owners and publishers of the content make, and they explicitly disclaim, any express or implied representations or warranties of any kind, including, without limitation, representations and warranties as to the functionality of the translation feature or the accuracy or completeness of the translations.
Translations are not retained in our system. Your use of this feature and the translations is subject to all use restrictions contained in the Terms and Conditions of Use of the BioOne website.
Vol. 86 • No. 3