Honeybee constancy to ultraviolet floral reflectance

Honeybees (Apis mellifera) were trained to artificial floral arrays to investigate their discrimination of, and constancy to, UV as a floral colour. The floral arrays enabled colour to be varied while other floral characteristics (odour, height, etc.) remained constant. Bees were trained to an array that had only one colour morph, and then were tested on arrays to which had been added increasing frequencies of an opposing floral colour-morpho Colours tested were yellow, UV and 'bee purple' (yellow plus UV). Bees trained to UV or bee purple remained constant to those colours when opposing colour morphs were inserted; bees trained to yellow were variable in their constancy. It was concluded that honeybees can not only discriminate between and remain constant to flowers when the sole floral cue difference is the presence or absence of UV reflectance, but also show a greater constancy to flowers having at least some UV reflectance.