Date of this Version
THE PRAIRIE NATURALIST, Volume 37, No. 2, June 2005, pp 61-71.
Nine species of sphecid wasps nesting in sparsely vegetated sandy soils near Ogallala, Keith County, Nebraska were studied during June 2003. The first records of the nest and prey of Cerceris clypeata gnarina Banks and Tachysphex williamsi R. Bohart are presented. Two species of weevils, Baris striata Say and B. subsimilis Casey, were prey of C. clypeata gnarina, with 12 to 22 individuals stocked per cell. Because B. subsimilis is a biological control agent for thistle, this finding is a caution to researchers not to ignore the potential impact of predatory wasps on the community. The single nest of T williamsi was a shallow burrow 5 cm deep; prey included grasshopper nymphs of Melanoplus sp. and M angustipennis (Dodge). The potential of Tachysphex spp. predation for regulating grassland grasshopper populations deserves further study, as a nest of T terminatus F. Smith contained early instar nymphs of six common grassland species, five of which constitute new prey records. A completed nest of Oxybelus subulatus Robertson contained a record seven cells each provisioned with four to seven male stiletto flies (Cyclotelus rufiventris (Loew), Therevidae). Truncated progressive provisioning with a single species of leafhopper (Cicadellidae) was practiced by Bembicinus nanus strenuus (Mickel), which differs from the progressive provisioning recorded for the one population previously studied. Observations of nests and prey of Bembix sayi Cresson, Cerceris jumipennis Ashmead, Philanthus psyche Dunning, and Plenoculus davisi davisi (Fox) were consistent with previous studies at other localities. Putative parasites of these nine wasp species included velvet ants (Pseudomethoca propinqua (Cresson), Dasymutilla vesta (Cresson), and D. nigripes sparsa Fox), cuckoo wasps (Hedychridium fletcheri Bodenstein and Hedychrum violaceum Brulle), and unidentified miltogrammine flies.