Like most wasps, the members of this family are predators, feeding their young on other insects (a few species prefer spiders). —Matt PelikanIt’s a ghoulish life history, to be sure, though it is shared by other groups of wasps. But it does mean that square-headed wasps play an important role in the ecosystem, helping to regulate the population sizes of their prey species. Like many other Crabronids, P. gibbosus (like our other members of the genus) is a black insect boldly marked with yellow. Calling to mind the figure of 30 Vineyard species that I cited earlier, you’ll surmise correctly that so far, many genera are represented here by just a single firmly identified species.