Reproductive Dominance Within Colonies of Bombus Terrestris (L.)

The primitive character of eusociality in bumblebees is expressed in the fact that laying workers appear beside the laying queen and in the severe outbursts of aggression that coincide with this phenomenon. Egg cells of both the queen and the workers are destroyed and in many cases the queen is killed. In the eight colonies that were investigated it was found that the queen switched from laying fertilized eggs to laying unfertilized eggs within a short period. The time when haploid (unfertilized) eggs were produced was derived from the demographic data of the colonies and from our present knowledge of the developmental time of the workers, the queens and the males. Egg laying by workers and overt aggression never occurred until the queen had stopped laying fertilized eggs. As a result, the interests of diploid brood were not affected by the worker-queen conflict in the colonies. The possible meaning of a specific worker display towards the queen, the so-called 'buzzing behaviour', is discussed in terms of the worker-queen relation.