BEES OF BOULDER COUNTY, COLORADO 24I 



SPHECODES LatreiUe 



All ours have the head and thorax black, the abdomen bright chestnut red. The 

 table is based on females. 



Small, anterior wing much less than 5 mm.; wings clear; mandibles red (Colo- 

 rado Springs, etc.) eustictus Ckll.* 



Larger, anterior wing slightly or greatly over 5 mm. long . . . .1, 

 When the abdomen is viewed from the side, a strong and deep constriction seen 

 between the first and second segments; size comparatively large: wings strongly 



smoky (Boulder) pecosensis Ckll. 



Abdomen without any, or any strong, constriction between first and second segments 



2. 

 Larger, anterior wing about 7 mm. long; vrings strongly dusky; mandibles biden- 



tate (Boulder, fls. Pulsatilla, April) hesperellus Pulsatillas Ckll. 



Smaller, anterior wing not over 6 mm 3. 



Wings practically clear; abdomen entirely red (Boulder) . . . sophiae Ckll. 

 Wings dusky; apex of abdomen black (Florissant) .... sulcatulus Ckll.* 



PROTERANER Robertson 



Similar to Sphecodes, but the abdomen is narrow, and the males appear in the 

 spring with the females, which is not the case with other Halictinae. In Europe 

 there is also a group of Sphecodes in which the males appear in the spring; thus 

 the male of 5. rubicundus v. Hag. has been taken in England in May, the male of 

 5. majalis Perez in France in April. I do not possess specimens of these species, 

 and cannot say whether they should be referred to Proteraner. 

 The Colorado species of Proteraner are as follows: 



Male about 9 mm. long, abdomen dark red, first segment black at base, and with 

 a large black spot on disk, apex broadly rounded (Boulder, Manitou, fls. Ribes) 



leptanthi CkU. 

 Male about 8 mm.; abdomen narrower and lighter, the basal half of first seg- 

 ment black (Manitou) rhois Ckll.* 



HALICTUS Latreille 

 The table is based on females. 



Head and thorax black i. 



Head and thorax green or blue 8. 



Abdomen red (Northern New Mexico, fls. Castilleia) .... ovalicepS Ckll.* 



Abdomen black, banded 2. 



Hind tibiae and tarsi clear red; size large; area of metathorax granular (Boulder, 



fls. Odostemon and Opuntia) lerouxii ruborum Ckll. 



Hind tibiae and tarsi dark, at most a little reddish, but with light hair . 3. 

 Cheeks broad, with a tooth beneath (Boulder, fls. Odostemon and Senecio) 



annaticeps Cresson. 



Cheeks not toothed beneath 4. 



Area of metathorax vrith strong ridges; abdominal segments with strong white 



basal bands; wings very clear (Boulder) sisjonbrii Ckll. 



Area of metathorax granular, or at most with minute feeble ridges or striae. 5. 



