Influence of pollen origin on performance of <i>Bombus terrestris</i> micro‐colonies

Abstract

Abstract The effect of the floral origin of pollen on the reproductive success of Bombus terrestris Latrum bumblebee (Apidae: Bombinae), was investigated by feeding micro‐colonies of queenless workers with different pollen types. We used a commercial pollen blend and three unifloral pollens, Prunus, Salix, and Taraxacum. Among the unifloral pollens, pollen quality did not influence egg production, but did influence egg laying delay and larval growth. The quality of pollens varied according to their protein content and protein efficacy (PE). Pollen from Prunus ( 27.5% w/w protein, PE = 10 ) resulted in the largest number of progeny, whereas Taraxacum ( 17.2% w/w protein, PE = 0 ) did not result in any offspring, due to high oophagy and larval ejection. Salix ( 20% w/w protein ) and the blend ( 222.8% protein ) diets gave rise to intermediate reproductive outputs. When pollen quality was sufficient for larval growth, the fitness of the male offspring was not affected over the range of the experimental diets. Our results suggest that quantitative and qualitative variations of pollen proteins have considerable influence on the reproductive success of bumblebees. Furthermore, larval growth has specific nutritive demands not provided by Taraxacum pollen, which is missing two essential amino acids.