WASP GENUS CERCERIS — SCULLEN 493 



Colorado: 9, Boulder Co., Sept. 10, 1926 (C. P. Custer). Nebraska: 9, 

 Halsey, Aug. 12, 1925 (L. C. Worley) ; 9, Sand Hills, Sept. ; 9, Glen, Sioux 

 Co., 4000 ft., Aug. 12, 1906 (P. R. Jones). South Dakota: 9, Hecla, July 26, 

 1928 (H. C. Severin). Wyoming: 9, Torrington, Sept. 20, 1939 (J. Standich). 



Prey record. — None. 



Plant record. — Solidago serotina (Nebraska). 



63a. Cerceris nigrescens nigrescens F. Smith 



Figures 89, 169a,b,c,d 



Cerceris nigrescens F. Smith, 1856, p. 466. — Cresson, 1865, p. 123. — Packard, 1866, 

 p. 62; 1872, p. 230.— Provancher, 1882, p. 75; 1883, pp. 643, 644.— Cresson, 

 1887, p. 282.— Schletterer, 1887, p. 497.— Provancher, 1889, p. 643.— Dalla 

 Torre, 1897, p. 468.— Peckham, 1898, p. 116, pi. 8, fig. 6.— Ashmead, 1899, 

 p. 295.— Viereck and Cockerell, 1904, p. 138.— Banks, 1912a, p. 20.— Stevens, 

 1917, p. 422.— Mickel, 1917b, p. 450.— Carter, 1925, p. 133.— Bischoff, 1927, 

 p. 208.— Krombein, 1936, pp. 94, 95; 1938, pp. 1-3.— Banks, 1947, p. 18.— 

 ScuUen, 1951, p. 1009.— Evans, 1957, p. 85, pi. 41, figs. 27-29.— ScuUen, 

 1960, p. 79. 



Female. — Length 12 mm. Black with cream-colored markings; 

 punctation somewhat less than average; pubescence short. 



Head slightly wider than the thorax; black except large frontal eye 

 patches, dorsal surface of the clypeal process, patch between the 

 antennal scrobes, spots back of the compound eyes, base of mandibles, 

 and small spot on the scape, aU of which are cream colored; clypeal 

 border extended on the medial lobe and forming lateral denticles, 

 between which is a broad projection consisting of lateral carina con- 

 nected by a thiner lamella; clypeal process convex above, slightly 

 broader than long, emarginate with the lateral points rounded; 

 mandibles with three small denticles, the apical one the most acute 

 and larger, the basal one low and broad, all fused at the base; antennae 

 normal in form, dark above, light below with a small yellow spot on 

 the scape. 



Thorax black except for two widely separated patches on the 

 pronotum, the metanotum, and patches on the tegulae, aU of which are 

 cream colored ; tegulae low and smooth ; enclosiu'e deeply ridged longi- 

 tudinally, but the ridges tending to spread apically; mesosternal 

 tubercle absent; legs dark to about the apical end of all femora, tibiae 

 dark above and cream below, tarsi cream with darkened areas; wings 

 subhyaline clouded with amber, darker toward the apex. 



Abdomen black except for two separated patches on tergum 1, 

 narrow bands on terga 2 to 5, all of which are cream colored; venter 

 immaculate; pygidium with the sides strongly converging apically to a 

 narrow rounded point. 



Male. — ^Length 10 mm. Black with cream-colored to creamy- 

 yellow markings; punctation and pubescence average. 



742-463 — 65 11 



