Morphologically, there is little difference between the foundress and subordinate reproductive members of the colony of polistes-dominulus. However, several studies have shown that behavioural differentiation occurs, the role the individual female taking determined by social interaction within the colony. Typically, the alpha female dominates all other individuals of a colony, and this female lays the majority of eggs, and partakes in differential oophagy. The alpha female devotes much of her time to social interaction, in comparison to subordinates that are much more involved in foraging and brood care.
These behavioural divisions are not permanent; if an alpha female is removed from a nest then another female (usually the second-most dominant, beta female) assumes the role and behavioural profile of the removed dominant. Indeed, individuals alternate between different profiles of behaviour within their own dominance rank position.
Some studies seem to indicate that the dominant female, through its behaviour, suppresses the ovarian development of subordinates. Abdominal wagging is thought to serve as a dominance signal between dominant foundresses and subordinates, but studies by Roseler and Roseler (1989) showed that ovariectomised dominants failed to restrict subordinate reproduction whilst still retaining dominance.
There are also evidently some factors present in the interactions of females on the nest that can influence which daughters become workers and which become gynes; despite some minor physiological differences (primarily in the fat body), "gyne-destined" females produced late in the colony cycle can be induced to become workers if placed on nests that are at an earlier stage of colony development, and the converse is also true. This indicates a significant degree of flexibility in the caste system of this species.
