Wild Bumblebee (Bombus) Diversity andNosema(Microsporidia: Nosematidae) Infection Levels Associated with Lowbush Blueberry (Vaccinium angustifolium) Production and Commercial Bumblebee Pollinators

摘要

The primary objective was to determine if the prevalence ofNosema bombiinfection is higher for wild bumblebees (Bombusspp.) caught in lowbush blueberry growing areas with a history of commercial bumblebee use than for bumblebees caught in areas without a history of commercial bumblebee use. Additionally, we wished to determine relativeBombusspecies abundances and diversity in blueberry growing regions. Over two years we caught, identified to species, and dissected 767 bumblebees. Light microscopy revealed overall infection levels of 5.48%. The history of commercial bumblebee use had no relation to infection levels. Bumblebee species diversity and field location had significant relationships to infection (r2adjusted = 0.265; species diversityF(1,22)=6.848,P=0.016; field regionF(1,22)=5.245,P=0.032). The absence or presence of one species,Bombus terricola, appears to determine the relationship between species diversity and infection. The data showB. terricoladecline in sampled regions and almost half of the collectedB. terricolawere infected withNosema. The commercial species,B. impatiens, shows an increase in abundance, but with a 6.9% proportion infection. Molecular confirmation of the infecting species was ambiguous, suggesting a need for future clarification of the infecting species.