Diurnal behavioural differences in forager and nurse honey bees (Apis mellifera carnica Pollm)K. Crailsheim, N. Hrassnigg and A. Stabentheiner
Institut für Zoologie an der Karl-Franzens-Universität, Universitätsplatz 2, A-8010 Graz, Austria
Abstract - Bees defined as nurses by age (7-12 days), or as foragers by behaviour, were observed for 1.5 h around noon during days with good weather conditions and during the following night around midnight. Nurse bees spent more than half of their time in the broodnest and their average periods of activity and inactivity were rather similar during day and night, except that the feeding of adults was more frequent during daytime. Foragers had a more cyclic lifestyle, spending most of their time outside the broodnest. During daytime they flew and had shorter periods of inactivity compared to nighttime and compared to nurse bees. Trophallactic interactions of foragers were much more frequent during daytime and they were more often fed than nurses. In contrast to nurses, we never saw foragers taking food from honey cells, and seldom visiting pollen cells. That foragers seldom eat honey and frequently receive food during daytime demonstrates the important role of passive trophallaxis for the foragers.
Key words: social behaviour / day and night / division of labour / trophallaxis