Apis dorsata has a regular annual cycle of migration in Sri Lanka. In February the colonies are spread throughout the coastal plains and the North Central Region. In June and July they migrate to the Up Country, which they leave again in October-November. The swarms seem to migrate in several stages, remaining for some days at a resting place between flights. These have different characteristics from the nest sites. Before the swarm flew off, migration dances indicated the direction of its departure. These dances occurred all over the cluster, unlike food dances which occurred only on the area where the light intensity was greatest. If the bees could not see the sun or sky, dance and flight activities were very low, but migration dances indicated a constant direction. With an indirect view of the sky through a mirror, activity was greater than with none, but the direction of migration dances was not changed. Swarms left in the direction indicated by migration dances. Queenless portions of swarms were able to become airborne suddenly, and to fly in a co-ordinated way. Cluster formation was induced by 1 mg 9-oxo-trans-2-decenoic acid. Author
Posted on: Mon, 03 Nov 2014 18:13:49 +0000