WASP GENUS CERCERIS — SCULLEN 405 



dark amber in the ocellar area; the gena and occiput are mottled with 

 yellow and amber. 



Thorax largely yellow and amber, which becomes mottled mth 

 darker shades or becomes very dark amber on the dorsum of some 

 specimens; scutellum, metanotum, and propodeum, including the 

 enclosure, vary from all yellow to mottled with yellow and light amber; 

 legs have variable amounts of yellow and light amber. 



Abdomen almost entirely yellow with some light amber margins. 



Male. — Males follow very much the color pattern and shades of 

 the females. 



Head largely yellow with light amber areas about the ocelli and 

 back of the eyes. 



Thorax mostly yellow with hght amber areas on the scutum, 

 becoming very dark on some specimens; legs yellow and light amber. 



Abdomen largely yellow with light amber borders. 



Cerceris califomica Cresson is easily confused with related species 

 found in the same areas, such as C. completa Banks and C. grandis 

 Banks. These are best separated by the characters given in the key. 

 The males of C. califomica arno Banks and C. grandis Banks especially 

 are difficult to separate. The surface sculpturing of the enclosure 

 has been found most useful by the author. The enclosure of the male 

 grandis shows evidence of ridges which become prominent in the 

 females of that species, while the enclosure of the male of califomica 

 arno is relatively smooth except for a few pits in the lateral angles. 



Types. — The type female of C. arno Banks is at the Museum of 

 Comparative Zoology, Harvard, no. 23541, and the type female of C. 

 argyrotricha Rohwer is at the U.S. National Museum, no. 28485. 



Distribution. — Southwestern desert area of California and 

 Arizona. 



Prey record. — None. 



Plant record. — Baccharis glutinosa (Arizona), cotton (Arizona), 

 Croton (California), Eriogonum albertianum neomexicanum (Arizona), 

 Prosopis juliflora (Arizona). 



26. Cerceris completa Banks 



Figures 33, 129a,b,c 

 Cerceris completa Banks, 1919, p. 83; 1947, p. 17.— ScuUen, 1951, p. 1006. 



Female. — Length 15 mm. Black with yellow markings; normally 

 pitted; clothed with short silvery hairs, which are somewhat longer 

 in the region of the propodeum and the first abdominal segment. 



Head shghtly wider than the thorax; black except the entire face 

 below the antennae other than the clypeal margin, base of the mandi- 

 bles, the scape, two elongate patches on the vertex, and patch on the 



