The effect of nectar abundance on foraging patterns of bumble bees

Abstract.

• 1 Bumble bees (Bombus spp.) fed more on previously screened, nectar-rich plots of cow vetch (Vicia cracca) and white clover (Trifolium repens), and remained longer on inflorescences there, than on continually-exploited plots of these flowers. No significant differences between previously screened and continually available plots occurred in the number of individuals visiting these two areas, the number of inflorescences per visit, the number of florets visited per inflorescence, and the percentage of inflorescences rejected.
• 2 Individual bees were analysed in greater detail. They visited more inflorescences and spent longer times on cow vetch in the previously-screened plots, whether moving from previously-screened to continually available areas, or vice versa. On white clover the same pattern held for bees moving from previously screened to continually available plots, but not for those moving from continually available to previously-screened areas.