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ARS Home » Midwest Area » Madison, Wisconsin » Vegetable Crops Research » Research » Publications at this Location » Publication #371525

Research Project: Cranberry Genetics and Insect Management

Location: Vegetable Crops Research

Title: Bees eat 'meat:' new perspectives on bee-microbe symbioses

Author
item Steffan, Shawn

Submitted to: Meeting Abstract
Publication Type: Abstract Only
Publication Acceptance Date: 1/22/2020
Publication Date: N/A
Citation: N/A

Interpretive Summary: n/a

Technical Abstract: Microbivory among animal species is pervasive. Bees, for example, are widely thought to derive all protein directly from floral resources, but recent findings suggest this is largely untrue. It appears that larval bees feed extensively on pollen-borne microbes, as well as the pollen, itself. These microbial prey are suffused throughout a fermenting pollen-provision. Because the microbes are actively consuming the pollen, these herbivorous organisms represent ‘microbial meat’ within the aging provision. Here, we provide empirical evidence of trophic omnivory across six of the seven extant bee families, revealing the prevalence of microbivory among the major bee fauna. We also looked at the roles of anthropogenic stressors on bee-microbial symbioses. For example, the risk of exposure to fungicide residues is likely to be high if the spray occurs on, or near, host plants while the bees are collecting pollen to provision their nests. We examined species of Bombus and Osmia, focusing on the roles of pollen-borne microbes in bee nutrition and fitness. Our findings suggest that bee-microbe symbioses are critical to larval bee development. When microbes are eliminated from pollen-provisions, larval mortality rises markedly. In essence, bees are omnivores because they consume significant amounts of 'microbial meat,' and these pollen-borne microbes are true symbionts.