HYMENOPTERA 951 



The members of this family are slender in form, with long spin}^ 

 legs, (Fig. 1 1 72). The pronotimi extends back on each side to the 

 tegula; and the abdomen is sessile. Many of the 

 species are of medium size, but some are ver\^ large; 

 in fact, the largest of our H^Tiienoptera belong to 

 this family. 



Most of the Pompilidffi make their nests in the 

 ground. The wasp first finds a spider and stings it 

 until it is paralyzed, and then digs a burrow, which 

 spider-wasp^ is enlarged at the lower end, forming a cell for the 

 reception of the spider; the spider is then dragged 

 down into the cell and an egg attached to it; then 

 the passage leading to the cell is filled with earth. Detailed accounts 

 of the actions of these spider-wasps when making and provisioning 

 their nests are given bv Peckham and Peckham ('98) and bv Rau 

 andRau ('18). " 



Among the giants of this family are the well-known tarantula- 

 hawks of the genus Pepsis of the Southwest, which store their bur- 

 rows with tarantulas. Many a hard-fought battle do these spider- 

 wasps have with these enormous spiders, and sometimes they are 

 conquered and ignominiously eaten. 



Not all members of this family are digger-wasps, for some are 

 mason-wasps. The species of the genus Pseudagenia make thimble- 

 shaped cells, of mud, attached to the lower surface of stones, in 

 chinks of walls, under bark and in various other situations; and at 

 least one species oiCeropales is said to be parasitic in the nests of 

 Pseudagenia. 



More than one hundred species belonging to this family have been 

 described from our fauna. A classification of the family was pub- 

 lished by Banks ('11). 



The family EMBOLEMID.^ includes only a few rare species the 

 habits of which are unknown. 



Family CLEPTID^ 



Cleptes 



This family includes only the genus Cleptes, which was formerly 

 included in the following family. But the genus Cleptes differs from 

 the Chr}^sididae in that there are six exposed segments in the abdomen 

 and the venter is convex. It is believed that these wasps are parasitic 

 in the cocoons of saw-flies ; as one of them infests the currant -worm 

 in Europe. Several native species are found in the Far West. 



Family CHRYSIDID^ 



The Cuckoo-Wasps 



The cuckoo-wasps are wonderfully beautiful creatures, being usu- 

 ally a brilliant metallic green in color. The species are of moderate 



