Bumblebee search time without ultraviolet light

Bees often facilitate pollination of important greenhouse crops. Individual bumblebees Bombus terrestris were therefore tested in an indoor flight arena to evaluate whether or not search time to find flowers was influenced by the inclusion or exclusion of ultraviolet radiation. Plastic model flowers of similar spectral properties to flowers of tomato Lycopersicon esculentum Mill. were used to evaluate bee search efficiency. The results show that bumblebees perceive when ultraviolet radiation is either removed or added to an illumination source; however, the bumblebees rapidly learn to find model flowers with equal efficiency in either illumination environment. The behavioural results are interpreted in relation to a colorimetric analysis showing how bumblebees are capable of using their visual system to forage efficiently in environments that exclude ultraviolet radiation.