Flower petal microtexture is a tactile cue for bees

Abstract

Honeybees are able to detect, learn and discriminate between microsculptured epidermes of flower petals. The sensilla trichodea at the tips of the bees'' antennae are in the same size range as the microsculptural features of the petals (.apprx. 10 .mu.m), which presumably deflect these mechanoreceptive sensilla in characteristic ways. Honeybees were trained to associate reward with 1 floral texture and to choose that over another. The bees also recognized differences in textures at different ends of petals of the same species. The phenomenon is significant in that it suggests another way in which insect pollinators can discriminate between the flowers of different plant species and so act as species isolators. The microsculptural patterns differ from 1 end of a petal to the other and, therefore, can be used as nectar-guides by foraging bees. A conditioned response to texture by insects and the functional significance of a floral character used in plant taxonomy are discussed.