13.5.2. Locating DCAs
Drone congregation areas are normally in proximity to the apiaries. In hilly regions, drones start in the direction of depressions in the horizon and stop at a suitable area (Ruttner and Ruttner, 1965). Up to now, the physical characteristics of a DCA have not been determined, so there is no other way of finding a DCA than to lift a queen or a queen dummy into the flight height of drones and wander in direction of the depression in the horizon (lightest point). The flight height may differ from 10 m to 40 m according to weather conditions and races of A. mellifera (Koeniger et al., 1989). Single drones near the apiary are often attracted by a queen, but they stay only for a short while. At the DCA, a swarm of drones will assemble around a queen. In flat areas, the horizon is uniform. Up to now, no DCA has been described for this landscape. Within 10 minutes, drones are attracted everywhere at some distance to the apiary.