390 



SOME REPRESENTATIVE INSECTS 



in the pithj^ stems of plants present further examples of this 

 interesting habit. 



Among social wasps, the species of the genus Polistes (Fig. 203) 

 represent a simple tj'pe of organization. These build nests of 

 " paper," obtained by the reduction of woody material to a 

 pulp3' mass somewhat after the manner of human paper-making, 

 although the paper mill of the wasp is its mouth parts. The 



female, after hibernating 

 through the winter, begins in 

 spring or early summer to 

 construct the nest, which is 

 suspended by a short stem and 

 arranged as a single layer of 

 "cells " placed side by side in a 

 " comb " with additions at the 

 margin. By the end of the 

 season, this nest may reach a 

 diameter of ten or twelve 

 inches. The single female, or 

 queen, which begins this con- 

 struction, is soon aided in tend- 

 ing the young and adding to 

 the comb b}^ other individuals, 

 the " workers," which hatch 

 from her eggs. When the larvae 

 are full-grown and ready to 

 pupate, the top of the cell is 

 sealed with paper through 

 which the larva breaks upon 

 emerging. The males are drones which do not work and die soon 

 after mating. In the fall, only functional females sur\dve. These 

 may be seen in large numbers in attics and similar places which 

 they seek for the winter hibernation. Polistes thus presents a 

 simple form of social organization. The nests of j-ellow-jackets 

 and the nests of hornets that hang from the limbs of trees are 

 composed of a series of combs resembling those of PoHstes but 

 enclosed in a common covering. 



Among the bees, there are solitary and social species and others 

 that present transitional stages. Hence, it is possible to pic- 

 ture the steps by which the highh^ organized communal life of a 



Fig. 203. — Social wasp, Polistes 

 bellicosus, and nest. 



(After Harman, loc. cit.) 



