182 



BRANCH AETHROPODA 



are fed by the queen with insects captured, killed, and somewhat masticated 

 by herself. In a few days the larva? pupate in the cells and socjn issue as 

 workers. These enlarge the nest, adding new brood cells, which the queen 

 fills with eggs; which, upon hatching, are fed by the work>'rs. 'Hius, several 

 broods of workers arc reared, and the nest is continually enlarged to make 

 room for the increasing family. Early in autumn a brood is hatched con- 

 taining males and females, which mate probably with individuals of other 

 communities, and at the approach of winter most of the colony dies, leaving 

 only a few hibernating queens. 



The nest of the social wasp may be under ground, in which case it is made 

 of partially decayed wood, or it may be attached to bushes or trees or under 



Fig. 148. — A hornet's nest, showing two horizontal sections of comb, one 

 above the other, and the many layers of paper surrounding the nest. (Photo- 

 graphed from object.) 



th(> eaves of buildings. This wood is formed into a pulp by being mast icated 

 with saliva and chewed. In the genus PoUa'lcs the nests consist of a single 

 cone and are not inclosed in an envelop, but in the genus I'r.s'/w;, including 

 the yellow-jackets and hornets, the nest (Fig. 14s i consists of several hori- 

 zontal cones suspended one above the other, yet m pa rated by a considerable 

 space from each other, and the whole enveloped in a waterproof covering of 

 many thicknesses of wasp-made paper, the whole nest forming a globular 

 or cone-shaped ball. When the nest is to be enlarged the wasps nibble away 

 the inner layers of the enveloping paste and add new layers on the outside. 

 Yellow-jackets and Hornets (Vespa). — In this genus the body of the 

 wasp is rather stout and short and the peduncle is very short. The color 



