Tactile conditioning and movement analysis of antennal sampling strategies in honey bees (Apis mellifera L.).

Honey bees (Apis mellifera L.) are eusocial insects and well known for their complex division of labor and associative learning capability(1, 2). The worker bees spend the first half of their life inside the dark hive, where they are nursing the larvae or building the regular hexagonal combs for food (e.g. pollen or nectar) and brood(3). The antennae are extraordinary multisensory feelers and play a pivotal role in various tactile mediated tasks(4), including hive building(5) and pattern recognition(6). Later in life, each single bee leaves the hive to forage for food. Then a bee has to learn to discriminate profitable food sources, memorize their location, and communicate it to its nest mates(7). Bees use different floral signals like colors or odors(7, 8), but also tactile cues from the petal surface(9) to form multisensory memories of the food source. Under laboratory conditions, bees can be trained in an appetitive learning paradigm to discriminate tactile object features, such as edges or grooves with their antennae(10, 11, 12, 13). This learning paradigm is closely related to the classical olfactory conditioning of the proboscis extension response (PER) in harnessed bees(14). The advantage of the tactile learning paradigm in the laboratory is the possibility of combining behavioral experiments on learning with various physiological measurements, including the analysis of the antennal movement pattern.