HYMENOPTERA 



973 



queen then is to produce the eggs. In the later part of the season 

 males and females are developed. 



The social wasps are predacious, and they feed their larvae upon 

 insects which they have malaxated. The wasps are also fond of the 

 sweets of flowers, the juices of fniits, and of noney-dew. They also 

 feed upon a liquid which the wasp larva emits from its mouth. This 

 exchange of nourishment between the larvee and the adults, termed 

 trophallaxis, is discussed in the Chapter on Isoptera, page 279. 



In the temperate regions the multiplication of colonies is brought 

 about by the production of many males and females in the nest in the 

 later part of the season; these pair, the females hibernate, and each 

 female founds a new colony in the spring. But in the Tropics many 

 of the Epiponinffi form large perennial colonies, which from tmie to 

 time give off swarms, in a way quite similar to the well-known 

 swarming of the honey-bee. 



Representatives of three of the subfamilies of social wasps are 

 found in America north of Mexico. The distinguishing characters 

 of these are indicated in the table of stibfamilies of the Vespidas given 

 above. 



Subfamily EPIPONIN^ 



This is a large group of wasps including a great variety of forms, 

 which exhibit great differences in the architecture of their nests. 



«+2d4 



Fig. 1 189. — Wings of Misclwcyttarus lahiatus: pi, posterior or anal lobe; ax. exc, 

 axillary excision. (From Bradley.) 



The species are mostly confined to tropical America; but three 

 are found in the southern portions of the United States. Figure 1 1 89 

 represents the venation of the wings of Mischocyttams lahiatus. 



Brachygastra lechegitdna.- — This species is found within the limits 

 of our territory only along the Mexican border. Its nest resembles 

 in form externally those of hornets {Vespa) but the combs are attached 



