Examining the nutritional value and effects of different floral resources in pumpkin agroecosystems on Bombus impatiens worker physiology
Floral enhancement schemes in agroecosystems are a common method to supplement bee dietary requirements, yet there is little information about how species used in these schemes influence bee physiology and how their nutritional value compares to the floral resources provided by the crop species. Here, we examined the pollen nutritional quality (macronutrient concentrations and protein:lipid ratio) of pumpkin (Cucurbita pepo, Cucurbitaceae), two species commonly used in enhancement schemes, Helianthus annuus (Asteraceae) and Crotalaria juncea (Fabaceae), a multifloral diet and an artificial diet. We tested effects of these diets on physiological characteristics of Bombus impatiens, a generalist pollinator. Bees performed best on real pollen diets, with consumption of C. juncea and multifloral pollen having the most pronounced effects on bee physiology. Our results underscore the importance of considering nutritional quality when selecting plant species for these schemes.
Keywordspollen nutrition bumble bee physiology floral rewards agroecosystems microcolonies
The authors thank Project Integrated Crop Pollination. We thank Laura Russo for providing pollen used in the multifloral diets. We also thank Hannah Balko and Nick Krause for their technical assistance in the field.
EDT: experimental design, performed experiments, data analysis, wrote manuscript.
ADV: conception of experiment, experimental design, data analysis, critical review.
CMG: conception of experiment, experimental design, critical review.
SJF: conception of experiment, data analysis, critical review.
All authors have given final approval to the version being published.
This material is based upon work that is supported by the National Institute of Food and Agriculture, U.S. Department of Agriculture, under award number 2012-51181-20105, Developing Sustainable Pollination Strategies for U.S. Specialty Crops.
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Conflict of interest
The authors declare that they have no conflict of interest.
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