Wasps, Bees, and Ants 



507 



places in our houses. Wasps of this genus are not infrequently parasitized 

 by the remarkable Stylopid beetles (Fig. 403) Xenos, of which an account is 

 given on p. 295. 



Fig. 713. — Queen-nest of yellow-jacket, Vcspa sp.; specimen at right in normal con- 

 dition; at left cut open to show brood-cells. (Natural size.) 



Only one species of Polybia occurs in the United States, and that one, 

 P. fiavitarsis (PI. XII, Fig. 12), is found only on the Pacific coast. It is 

 common in California. It is readily distinguishable from the other social 

 wasps by its slender pedunculate basal abdominal segment and the small 

 button-like shape of the rest of the abdomen. It builds a single-comb, 

 unenveloped nest, like that of Polistes, but not reaching the diameter of 

 the broad disk-hke Polistes comb. 



It has been mentioned that the social wasps feed their young (larva?) 

 chewed insects. Differing from most of the sohtary wasps, the .social kinds 

 do not store up food for the young, but collect and bring it constantly through 

 the life of the larva;, a period of from eight to lifteen days. This food con- 

 sists of the partially masticated remains of various insects pursued and killed 

 by the queen or workers. The queen brings food only for the lar\x' of the 

 first small spring brood. 



The adult wasps arc more catholic as regards the palate; they feed on 

 insects or decomposing animal substances — fish especially attract them — 

 and on exposed sweet substances, as sirups, preserved fruits, etc. 



The paper-making and nest-building are industries whose details can 

 only be touched on in our limited space. The paper is not only made of 



