Nutritional composition of honey bee food stores vary with floral composition

Geraldine A. Wright,Philip Donkersley,Roger W. Pickup,Glenn Rhodes,Eileen F. Power,Kenneth Wilson,Kevin C. Jones

doi:10.1007/s00442-017-3968-3

Geraldine A. Wright, Philip Donkersley + Show 5 more

Open Access

https://doi.org/10.1007/s00442-017-3968-3

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Abstract

Sufficiently diverse and abundant resources are essential for generalist consumers, and form an important part of a suite of conservation strategies for pollinators. Honey bees are generalist foragers and are dependent on diverse forage to adequately meet their nutritional needs. Through analysis of stored pollen (bee bread) samples obtained from 26 honey bee (Apis mellifera L.) hives across NW-England, we quantified bee bread nutritional content and the plant species that produced these stores from pollen. Protein was the most abundant nutrient by mass (63%), followed by carbohydrates (26%). Protein and lipid content (but not carbohydrate) contributed significantly to ordinations of floral diversity, linking dietary quality with forage composition. DNA sequencing of the ITS2 region of the nuclear ribosomal DNA gene identified pollen from 89 distinct plant genera, with each bee bread sample containing between 6 and 35 pollen types. Dominant genera included dandelion (Taraxacum), which was positively correlated with bee bread protein content, and cherry (Prunus), which was negatively correlated with the amount of protein. In addition, proportions of amino acids (e.g. histidine and valine) varied as a function of floral species composition. These results also quantify the effects of individual plant genera on the nutrition of honey bees. We conclude that pollens of different plants act synergistically to influence host nutrition; the pollen diversity of bee bread is linked to its nutrient content. Diverse environments compensate for the loss of individual forage plants, and diversity loss may, therefore, destabilize consumer communities due to restricted access to alternative resources.

Highlights

Communicated by Ingolf Steffan-Dewenter.Electronic supplementary material The online version of this article contains supplementary material, which is available to authorized users.Biodiversity is central to the sustainable functioning of ecosystems
The protein to carbohydrate ratio was 1.58:1 ± 1.00. μHPLC analysis revealed 17 amino acids present in the 49 bee bread samples (2 samples were lost during HPLC analysis; Fig. 1, Table S4)
This study measured the relationships between the pollen and nutritional compositions of bee bread from hives of the honey bee (A. mellifera)

Summary

Introduction

Biodiversity is central to the sustainable functioning of ecosystems. Resource diversity can result in increased consumer community diversity and broader ecosystem function (Balvanera et al 2006; De Deyn et al 2004). Studies have begun to investigate the effects of resource diversity at the individual level (Drescher et al 2014). Three distinct mechanisms explain how biodiversity can result in benefits to a community—through redundancy (where resource scarcity in one species is compensated by another), complementarity (where diverse diets have direct benefits to consumer growth, development or immune function) and “functional balance” (where multiple sources of resource enable balancing of intake to a target) (Drescher et al 2014; Finke and Snyder 2008; Wohl et al 2004)

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