Temporal acuity of honeybee vision: behavioural studies using flickering stimuli

ABSTRACT. Temporal resolution of freely-flying bees was measured by training bees, Apis mellifera (Linn.), to discriminate between a steady light and a flickering light. Two kinds of experiments were conducted: those using a homochromatic flicker, in which the intensity of the flickering light varied periodically with time; and ones using a heterochromatic flicker, in which the colour of the flickering light varied periodically. In either case, the time-averaged properties (intensity and colour) of the flickering light matched those of the steady light, and the bees' ability to discriminate between the two stimuli was measured for various flicker frequencies. The results indicate that bees perform poorly in the homochromatic flicker experiments, regardless of the colour of the light (u.v., blue or green), but well in those with heterochromatic flicker. Heterochromatic flicker experiments using various pairwise combinations of the colours U.V., blue and green (corresponding to the three known spectral receptor-types in the bee's retina) reveal that temporal resolution is much better when blue is one of the component colours, than when it is not. The simplest interpretation of the results is in terms of colour channels possessing different response speeds. Heterochromatic flicker promises to be a useful tool in investigating the temporal properties of colour vision in bees.