Effects of experimental plant density reductions on plant choice and foraging behaviour of bees (Hymenoptera: Apoidea)

Abstract

This investigation tested how a reduction in plant density affected the willingness of bees to visit a number of palaearctic plant species. Pairwise comparisons were made between the first bee visits to control and manipulated plots. The results showed that bees still chose and utilized plant species with a small number of open flowers in the density-reduced plots. In plant species with a larger number of flowers, bees often chose the dense plots or did not visit as many flowers on plants in the density-reduced plots, Multiflowered plants may produce only small amounts of nectar in order to discourage pollinators from foraging too long in the inflorescences. This would result in a decrease in the number of self-pollination events and an increase in pollen export.