656 



THE STUDY OF INSECTS. 



A very common species in the East is Stigmus fraternus 

 (Stig'mus fra-ter'nus). This insect measures one fifth of an 

 inch or less in length, and makes very tortuous burrows in 

 the pith of sumach (Fig. 782). Other common members of 

 the family are larger. 



Family CRABRONIDS (Cra-bron'i-dse). 

 The Crabronids {Cra! bro-nids). 

 The Crabronids can be distinguished from all other digger- 



FiG. 783. — Win^s of Crabo singularis. 



wasps that occur in this country by the vena- 

 tion of the fore wings, in which there is only 

 one closed submarginal cell (Fig. 783, 

 2d III -f- III 5 ). The head is gener- 

 ally large, and nearly square when 

 viewed from above, and sometimes 

 broader than the thorax (Fig. 784). 

 c'rabro. The different members of this 



family vary greatly in their nesting habits. 

 Some mine in the pith of such plants as sumach 

 and elder; some bore in more solid wood; 

 some dig burrows in the ground ; and others 

 make use of any suitable hole they can find, 

 often the deserted burrow of some other in- 

 sect. These insects usually provision their nests 

 with flies ; but we have found spiders in the 

 nests of some. 



! 



I 



Fig. 785.— Nest of 

 Trypoxylon fri- 

 pidum. 



