Tactile learning in the honeybee

Free-flying bees were conditioned on a vertical wall to a vertical tactile pattern consisting of parallel lines of grooves and elevations. The asympto te of the learning curve is reached after approximately 25 rewards. Bees ca n discriminate the conditioned vertical pattern from a horizontal or diagon al alternative. Angle discrimination is apparent only for relatively coarse tactile cues. The proboscis extension response of fixed bees was used to c ondition bees to a vertical tactile pattern which was presented to the ante nnae. The learning curve reaches an asymptote after 4 rewards. After 7 unre warded extinction trials the conditioned responses are reduced to 50%. Bees show best discrimination for patterns whose edges they can scan with their antennae. The animals show a high degree of generalization by responding t o an object irrespective of the trained pattern. Under laboratory condition s fixed bees can discriminate the angles and spatial wavelengths of fine ta ctile patterns consisting of parallel grooves. Bees can also discriminate f orms and sizes of tactile patterns. They do not discriminate between differ ent types of edges and between positive and negative forms.