358 



APPLIED ENTOMOLOGY 



ground; others tunnel in wood and divide the tunnel into cells by cross 

 partitions of mud; while others build cells of mud. some kinds of which, 

 attached to twigs are like jugs or urns (Fig. 377) in form, with an upper 

 flaring lip which, after the nest has been stocked with food for their young, 

 is sealed with mud. The mud workers of this 

 family are often called the Mason-wasps. All 

 the wasps of this group are predaceous. 



In the family Vespidse we come to the social 

 wasps, living in colonies, and with three types of 

 members, the males, females and workers, these 



Fig. 376. 

 Fig. 377. 



Fig. 376. Fig. 377. 



-Eumenid Wasp {Eumenes fralernus Say), natural size. {Original.) 

 -Two nests oi Eumenes fraternus, natural size. (Original.) 



last being females in which the reproductive organs have undergone 

 little or no development and the insects themselves are smaller than the 

 true females. 



The colonial life of these insects continues only during the summer, 

 all but the females dying as winter approaches. In the spring the 



Fig. 378. Fig. 379. 



Fig. 378. — Social Wasp (Polistcs pallipes Lep.), about natural size. {Original.) 

 Fig. 379. — Nest of Polistes pallipes, as found before the colony has increased much 

 in numbers. Reduced slightly. {Original.) 



female (Fig. 378) starts a colony, first building a cluster of six-sided cells 

 which are in some cases attached to the under side of some projecting 

 rock, eaves, or in a similar position (Polistes) . These cells (Fig. 379) are 

 made from weathered wood, chewed up by the insect into a sort of gray 



