Reproduction in foundress associations of the social wasp, Polistes carolina: conventions, competition, and skew

Who reproduces in colonies of social insects is determined by some combination of direct competition and more peaceful convention. We studied these two alternatives in foundresses of the paper wasp, Polistes carolina, by examining two different contexts: what determines who becomes the dominant reproductive and what determines the amount of reproduction obtained by subordinates. The dominant queen on most nests was the foundress to arrive first, rather than the largest foundress, expected to be best at fighting. This suggests that dominance is initially determined by convention, although the persistence of some aggressive conflict throughout the foundress period suggests that this convention is not absolute. Attempts to explain the division of reproduction using several skew theories were generally unsuccessful. Skew was not correlated with relatedness, size differences, colony productivity, and challenges by the subordinate. P. carolina showed high constraints against solitary nesting, with a minority of females attempting to nest alone, and none succeeding. In this situation, most skew theories predict that group stability will be independent of relatedness, yet nearly all collected subordinates were full sisters to the queen. Reproductive partitioning in early P. carolina colonies may have more to do with enhancing worker production than with conflict over direct fitness.