Floral constancy in bees: a revision of theories and a comparison with other pollinators

Abstract

Bees make choices about what flowers to visit among the options in the floral market. Bee specialization to visit only one plant species at a time is relevant to maintain the plant-bee mutualism. angiosperms derive a clear benefit in their sexual reproduction from the fidelity exhibited by the bees; less obvious is why the insects engage in this behavior. The phenomenon of flower constancy in bees is known from more than two millennia ago yet there is no general theory that can explain all kinds of flower constancy. In this paper I review different theories on flower constancy, providing evidence in favor and against each model, and then I discuss the possible scenario in which each behavior can have an ecological advantage. Finally, I present evidence of flower constancy exhibited by other groups of insects and vertebrate pollinators.