Abstract:
Montezumia cortesioides is of special interest for studies of insect social evolution because it belongs to the primarily solitary-nesting subfamily (Eumeninae) of wasps that is most closely related to the subfamilies (Stenogastrinae, Polistinae, Vespinae) that contain eusocial species. It is one of a few eumenines that are primitively, social, with more than one reproductive female on the same nest without a division of labor between sterile workers and egg-laying queens. Most of the 17 known progressively provisioning eumenines nest as solitary females, but there is an association between progressive provisioning and nest sharing: all of the three nest-sharing eumenines whose behavior has been observed progressively provision their larvae. Of those species, the behavior of M. cortesioides most closely resembles that of the eusocial (worker-containing) wasps, in nest-sharing, reuse of brood cells, progressive provisioning, and strong aggressive competition among resident females for empty cells. Observations suggest that groups are formed when offspring females remain on the maternal nest. A male repeatedly visited a nest and paired with a newly emerged female. Prey theft from the open cells of nestmates (intranidal prey theft) was associated with episodes of self-grooming and brief repetitive superficial inspections of prey-containing cells.
