Pattern vision in honeybees (Apis mellifera): Flower-like patterns with no predominant orientation

Abstract

Flying honeybees (Apis mellifera) discriminate colour, pattern disruption (equivalent to flicker induced by self-motion) and orientation of edges, but they are unable to distinguish between a + and a x pattern of four bars arranged at right angles. We find that they cannot distinguish between the four bars arranged in a square and the same rotated by 45°, but the square is discriminated from the cross. Bees also distinguish between a symmetrical radial pattern and one of concentric circles, and between either of these and a neutral pattern. Having learned on sectors and circles, they discriminate a cross from a square. Therefore the local orientations are not summed over the whole target and a new model is required. We propose that the bees have detectors for symmetrical radial and circle patterns in parallel with those for orientation, and local orientation is neglected when these global (total target) detectors are excited. These experiments provide further evidence for innate filters for flower-like symmetry irrespective of rotation. The proposed detectors and those previously proposed for orientation, size, colour and flicker, are relatively independent of range.