HYMENOPTERA 969 



Subfamily BEMBICIN^ 



Tribe PHILANTHINI 



In this tribe the upper margin of the clypeus is suddenly expanded 

 into a broad median lobe, usually rhomboidal, extending upward 

 toward the antennas 

 (Fig. 1205). 



These wasps bur- 

 row in the ground; 

 some species provision 

 their nests with ants 

 others with bees. 



Tribe CERCERINI 



In the Cercerini 



the hind femora are „. ^ ^^. . . . 



u J J 4-j-u Fig. 1206. — Hind lee; of 



broadened at the apex, ^Cerceris dypeata. 



there forming a trans- 

 verse reniform plate (Fig. 1206); in both male and female there is a 

 distinct pygidial area; the transverse part of vein M is distant from 

 the stigma by less than twice the distance between the apex of the 

 cell 2dRi+R3 and the apex of the wing (Fig. 1207); and the anal 

 lobe of the hind wings is large. 



Fig. 1205. — Face of a 

 philanthid; c, clypeus. 



Fig. 1207. — Wings of Cerceris. 



The species of Cerceris usually burrow in the ground and provision 

 their nests with beetles; but some provision their nests with bees 

 {HalictMs) 



Tribe NYSSONINI 



In the Nyssonini the ocelli are never distorted and the upper 

 margin of the clypeus extends directly across in a straight line or an 



