The polyembryonic parasitoid wasp, Copidosoma floridanum, has evolved a caste system, consisting of soldiers and reproductives. Prior studies suggest soldiers have evolved in response to two selective pressures: 1) defense against competitors, and 2) resolution of sex ratio conflict. Prior studies indicate that soldier development time critically influences the outcome of intraspecific competition, and may also be strongly influenced by allelic variants of the metabolic enzyme, glucose phosphate isomerase (Gpi). Other studies suggest sibling conflict exists in mixed sex broods due to the potential mating opportunities for males with both sisters and females from other hosts. My results indicate that Gpi is a gene of major effect in the timing of soldier emergence and outcome of competition. Other experiments indicate that brother-sister matings commonly occur in mixed broods but that mating opportunities for males after dispersing from the natal patch are low.
