The importance of the egg-mass to the activity of normal queens and microgynes ofMyrmica rubra L. (Hym. Formicidae)

Summary

• 1. The results are described for three experiments investigating the grouping, in small observation nests, of queens of the antMyrmica rubra L.

• 2. The first describes how a group of normal queens, without workers, establishes an egg-mass which acts as a core. Then when workers are introduced, how they gradually take over the general duties of the colony while the queens' activities are concentrated in the core.

• 3. The second describes the behaviour of a large natural group of microgynes and workers in the observation nest. It shows that microgynes, like normal queens, establish a core. Reduction in the worker population does not seriously affect the colony's structure.

• 4. The third experiment describes what happens when normal queens and microgynes are grafted (a process of gradual introduction) into small colonies of the other type. Contrary to expectation the newly grafted queens, of whichever type, monopolized the core at the expense of the familiar queens.

• 5. The importance of the core for the activity and breeding success of queens is reviewed and the results of the three observation experiments are discussed in the light of this review. Especial emphasis is given to the social status of microgynes within colonies in relation to the alternative views: that they are either true social parasites or some form of balanced polymorphism.