Nesting Biology of the Sand Wasp Síictia heros (Hymenoptera: Sphecidae: Nyssoninae) in Costa Rica

Abstract

Female Stictia heros in Costa Rica nested in a large (1500 wasps) aggregation as well as in scattered, small (<20) clusters. They individually provisioned unicellular nests progressively with a variety of flies. Burrows were deep (X = 68 cm) and inner and outer closures were maintained at all times. Cell cleaning and the digging of accessory burrows were observed for the first time in the genus Stictia. These behaviors probably contributed to the low incidence of predation on and parasitism of larvae (2 of 23 excavated cells contained dipteran maggots or puparia). Cleptoparasitism of prey by conspecific females was commonplace.