Experimental hosts.—"Field cockroaches," Philippine Islands (Williams, 1944).
Nesting site.—Readymade crevices or holes in ground; porosity in lava. Behavior.—The wasp seizes the cockroach by a cercus or leg and stings it in the thorax. She (fig. 7, A) then drags the cockroach to the nest by the base of an antenna. Wasp bites off distal part of host's antennae. She deposits her egg on one of the host's midcoxae. Nest is plugged with lumps of soil. The larva eats the entire host. Development.—Eggs hatched in about a day and a half. Adults emerged about 3 weeks later. About five generations per year. (Williams, 1918, 1919; Williams et al., 1931.)
Dolichurus sp.
Natural hosts.—Cockroaches, nymphs, South Africa (Bridwell, 1917). Adult female cockroach carrying an oötheca, France (Deleurance, 1943).
Nesting site.—Plant stem, or in ground possibly an old abandoned nest of Ammophile. Behavior.—Bridwell noted that one wasp larva ate two cockroach nymphs before pupating; the adult emerged about 4 months after cocoon formation. Deleurance observed the wasp close its nest with small pebbles, balls of earth, and small dead branches. The wasp egg was placed on the femur of the midleg. The prey in the nest is alert when disturbed. Deleurance believed the wasp was a variety of D. corniculus.
Trirhogma caerulea Westwood
Natural hosts.—Periplaneta americana and Periplaneta australasiae, Formosa (Sonan, 1924): The wasp stings a nymph about one inch long and carries it to a suitable place (bamboo pipe) for oviposition.