[Illustration: FIG. 7.--Cockroach-hunting wasps. A, _Dolichurus stantoni_ leading a nymph of _Blattella lituricollis_ to her nest, c. × 4. (Reproduced from F. N. Williams [1919].) B, _Podium haematogastrum_ attaching her egg to an _Epilampra_ sp. while on the side of a termite mound that contains the wasp's nest, c. × 1.6. C, _Epilampra_ sp. parasitized by _P. haematogastrum_ showing the wasp's egg attached to the right fore coxa, c. × 3.2. (B and C reproduced from Williams [1928], through the courtesy of Dr. F. X. Williams and F. A. Bianchi.)] =Trirhogma= sp. _Natural hosts._--Cockroaches, Oriental region (Williams, 1918, 1928): As far as is known species of this genus of wasps hunt cockroaches. Family SPHECIDAE =Tachysphex blatticidus= Williams _Natural hosts._--_Chorisoneura_ sp., adults, Trinidad, St. Augustine (Callan, 1942): The wasps nest gregariously in sandy places. The wasp itself is parasitized by the mutillid _Timulla_ (_Timulla_) _eriphyla_ Mickel. Cockroaches, Trinidad (Williams, 1941a; Callan, 1950). =Tachysphex coriaceus= Costa _Natural hosts._--Cockroaches, Italy (Beaumont, 1954). =Tachysphex fanuiensis= Cheesman _Natural hosts._--_Graptoblatta notulata_, Society Islands (Cheesman, 1927, 1928). Cockroach ("except for its smaller size [it] much resembles _Graptoblatta notulata_."), New Caledonia (Williams, 1945). _Nesting sites._--Patches of dry soil (Cheesman, 1928); coarse sand at base of a bank (Williams, 1945). _Behavior._--The female wasp pounces on the cockroach and stings it into immobility; she carries her prey in flight to the nest. Two to 13 cockroaches may be found in one nest; and one or more wasp eggs may be deposited in one nest. The egg is attached at one end to the host's thorax behind a forecoxa. Nest is sealed with dry pellets of soil. The cockroaches apparently do not recover from the wasp's sting. =Tachysphex lativalvis= (Thomson) _Natural hosts._--_Ectobius lapponicus_, adults, Sweden (Adlerz, 1906); France (Maneval, 1932). _Ectobius pallidus_, nymphs, France (Ferton, 1894, 1901; Maneval, 1932; Deleurance, 1946); Italy (Grandi, 1928). _Ectobius panzeri_, Netherlands (Bouwman, 1914). _Ectobius_ sp., Denmark (Nielsen, 1933).