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Janko Bozic : Curriculum Vitae

Scientific interest

Managing and planning foraging of honeybee colonies is a priority of any beekeeper in the world. In early eighties I started investigating basic concepts of foraging behavior of honeybees. Dance communication is mayor biological mechanism that promotes foraging success of a honeybee colony. Two honeybees are always involved in the dance communication, the dancer bee and bee that collect the dance message. The dancer bee emits the direction and distance message whereas the bees around the dancer receive the information. In the eighties the most popular hypothesis of the message transfer proposed that the message is transmitted via sound vibrations that are detected by bees in the near acoustic field around the dancer (Kirchner, Michelsen). A novel definition of behavior of bees surrounding the dancer was needed. The followers bees move along with the waggling dancer always touching its thorax and abdomen with both antennae.The attender bees stand around the dance field, do not follow and do not touch the dancer. The initially inactive bee starts attending the dancer, gets excited and potentially starts following the dancer. Not all the attenders will follow the dancer, however only the follower bees can find a distant food source successfully. Before flying in the direction of the foraging site the follower bees leave the hive and orient around the hive several times in succession. The honeybee foraging behavior is always accompanied by large changes in hemolymh sugar concentrations, concentrations of glucose, fructose and trehalose in hemolymph are activity dependent. The concentration of trehalose is high during departure from the hive and it decreases during the hive return. The concentrations of glucose and fructose are high in the follower bees and in the foraging bees. Biogenic amines and juvenile hormone also control some aspects of the foraging behavior. Concentrations of biogenic amines change during the waggle dance activity. The follower bees have higher activity of dopamine than the inactive bees. Increased octopamine concentrations are linked to feeding arousal of honeybees. Serotonin concentrations increase during the decline of foraging activity. The queen pheromone is transferred passively from the queen to its attending bees, and further from the queen attending bees to other bees in the hive.

Ripe fruits frequently contain ethanol and facilitate natural ethanol exposure of honeybees. With the group of C. Abramson from Oklahoma State University of we started investigating ethanol effects in honeybee behavior. Honeybees are thus becoming a model for drug abuse and toxicity studies in insects.