Trichromatic colour vision in the hummingbird hawkmoth, Macroglossum stellatarum L.

Hymenopterans have long been shown to choose colours by means of the spectr al distribution and independently of the intensity (true colour vision). Th e same ability has only very recently been proven for two butterfly species . We present evidence for the existence of true-colour vision in the Europe an hummingbird hawkmoth, Macroglossum stellatarum. Moths were trained in du al-choice situations to spectral lights of a rewarding and an unrewarding w avelength. After training, unrewarded tests were performed during which the intensities of the lights were changed. The results confirm that the speci es has three spectral receptor types and uses true colour vision when learn ing the colour of a food source. If colour vision is not possible since onl y one receptor type is receiving input from both stimuli, the moths learn t o associate some achromatic cue correlated to the receptor quantum catch, w ith the reward. The moths learn spectral cues rapidly and choose correctly after one to several rewarded visits even when trained to different colours in sequence.