TACTILE MOTOR LEARNING IN THE ANTENNAL SYSTEM OF THE HONEYBEE (APIS-MELLIFERA L.)

Honeybees fixed in small tubes scan an object within the range of the antennae by touching it briefly and frequently. In our experiments the animals were able to scan an object for several minutes with the ante nnae. After moving the object out of the range of the antennae, the an imals showed antennal movements for several minutes that were correlat ed with the position of the removed object. These changes of antennal movements are called ''behavioural plasticity'' and are interpreted as a form of motor learning. Bees showed behavioural plasticity only for objects with relatively large surfaces. Plasticity was more pronounce d in bees whose compound eyes were occluded. Behavioural plasticity wa s related to the duration of object presentation. Repeated presentatio ns of the object increased the degree of plasticity. After presentatio n durations of 30 min the animals showed a significant increase of ant ennal positions related to the surface of the object and avoidance of areas corresponding to the edges. Behavioural plasticity was compared with reward-dependent learning by conditioning bees to objects. The re sults of motor learning and reward-dependent conditioning suggest that bees have tactile spatial memory.