WASP GENTJS CERCERIS — SCULLEN 503 



Head without yellow spot back of the eye; surface of medial clypeal 

 lobe more convex on posticata. 



Thorax very close to that of sexta Say except that patch on the pro- 

 podeum is smaller than on the latter species. 



Abdomen with band on tergum 2 very slightly wider and bands on 

 terga 3 to 6 narrower than on sexta Say; bands on sternites more limited 

 than on sexta Say. 



C posticata Banks is known only from the unique type male. It is 

 very close to the male of C. sexta Say and may prove to be that species. 

 For the present, the writer will retain it as a valid species. 



Type. — The holotype male, from Jemez Mountains, N. Mex., 

 July 11 (Woodgate), is at the Museum of Comparative Zoology, 

 Harvard, no. 13771. 



Prey record. — None. 



Plant record. — None. 



67. Cerceris rhois Rohwer 



Cerceris rhois Rohwer, 1908, p. 325.— Scullen, 1951, p. 1010. 



Female. — Unknown. 



Male. — Length 12 mm. Black with yellow and light fulvous 

 markings; close to male of C. sexta Say in structural details and color 

 pattern except as indicated below. 



Head with the medial clypeal denticle somewhat smaller than the 

 two lateral denticles. 



Thorax lacks the yellow patches on the propodeum of C. sexta Say. 



Abdomen with band on tergum 1 not emarginate and other ab- 

 dominal bands narrower than on sexta. 



C. rhois Rohwer is known only from the unique type male. It, like 

 C. posticata Banks, is very close to the male of C. sexta Say and may 

 prove to be the same species. This also the writer prefers to retain 

 as a valid species until better characters are found for separating 

 closely related males. 



Type. — The holotype male, from Rio Ruidoso, White Mts., New 

 Mexico, about 6500 ft., July 21, on flowers of Rhus glabra (C. T. 

 H. Townsend), is at the U.S. National Museum, no. 28482. 



Prey record. — None. 



Plant record. — None. 



68. Cerceris serripes (Fabricius) 



Vespa serripes Fabricius, 1781, p. 464. 



Cerceris serripes, Bequaert (not Fabricius) 1928, p. 62 (misassociation for C. 



bicornuta Guerin) .—Scullen, 1942, pp. 188, 189.— Strandtmann, 1945, 



p. 311.— Van der Vecht, 1961, p. 67. 



