950 



AN INTRODUCTION TO ENTOMOLOGY 



Fig. 1 17 1. — 

 Evania ap- 

 pendigaster 



the abdomen is attached to the dorsal surface of the propodeum (Fig. 



1 1 7 i) in- 

 stead of at 

 the hind 

 end of it, as 

 it is in the 

 following 

 families. 

 Theab- 

 domen is 



short and carried aloft — 

 like a flag; this fact sug- 

 gested the common name 

 ensign-flies for these in- 

 sects. 

 The venation of the wings is greatly reduced, and in the hind 



wings there are no closed cells; the trochanters are two-segmented; 



and the ovipositor is not at all or but little exserted. 



All of the species are parasitic in the eggs of cockroaches. 



This family was monographed by Bradley ('08) and Kieffer ('12) 



It is represented in our fauna by two genera, Evania and Hyptia. 



SUPERFAMILY VESPOIDEA 



Fig. 1 1 70. — Wings of Evania appendigaster;!, anal 

 lobe. 



The Vespoid-Wasps 



This superfamily is one of three superfamilies, the Evanioidea, 

 the Vespoidea, and the Sphecoidea, in which the hind wings are 

 typically furnished with an anal lobe; but in some of the more 

 specialized members of the Vespoidea and of the Sphecoidea the anal 

 lobe has been lost. This is the case in certain genera of the Formi- 

 cidcc, Mutillidas, and Vespidas; these exceptional forms can be placed 

 by the table of families on pages 906 to 915. 



The members of Vespoidea differ from the Evanioidea in that the 

 petiole of the abdomen is attached to the hind end of the propodeum; 

 and they differ from the Sphecoidea in that the lateral extensions of 

 the pronotum, which reach the tegulas (except in the Cleptidae and 

 Chrysididas) , are not in the form of well-differentiated rounded lohes, 

 as is the case in the Sphecoidea. See Figure 1195 on a later page. 



The Vespoidea is represented in our fauna by fourteen fnmilics ; 

 these can be separated by the table of families referred to above 



Family POMPILID^ 



The Spider-Wasps 



The members of this family are commonly called spider-wasps, 

 because they provision their nests with spiders ; this habit, however, is 

 not distinctive as certain other wasps use spiders for this purpose. 



