356 economic entomology 



Group Vespoidea (Wasps) 



The true wasps are divided into the SoUtary Wasps {EtimenidcB) 

 and the Social Wasps {Vespidce). The former have similar habits to the 

 Digger Wasps (see below), forming burrows in the earth, in wood or on 

 twigs of shrubs. In the latter class two genera are common, Polistes 

 with a spindle-shaped abdomen, and black ringed with yellow, and 

 Vespa, the common hornet or yellow-jacket. The paper nests attached 

 to buildings, trees or in the earth are constructed from bits of wood made 

 into a pulp, and are provisioned with spiders or insects. The nest of 

 Polistes consists of a single comb, attached by a short stem, but that 

 of Vespa consists of several layers of combs with a papery covering. 



The White-faced Hornet is well known as the maker and owner of 

 the large paper nest. It provides its young with noxious larvae, and un- 

 doubtedly does much to control insect life. Occasionally, however, it 

 may injure grapes or peaches by eating holes in them. The life-history 

 is quite similar to that of the Bumble Bee — males, females and workers 

 (undeveloped females) making up the colony. Only the females sur- 

 vive the autumn and hibernate. 



Group Sphecoidea (Digger Wasps) 



The Digger Wasps contain a large number of families. (See Com- 

 stock's Manual of Insects and Hymenoptera of Connecticut.) They are 

 solitary and store their nests with paralyzed insects or spiders. The 

 nests vary in structure; some are made of mud attached to ceilings of 

 buildings, some made in the pith of elder, sumach, etc., and others in 

 sandy banks. The more common genera are Tiphia, Peloposus, 

 Sphecius, Stigmus and Trypoxylon. 



Group Apoidea (Bees) 



The bees are grouped into two families, the Andrenidce (Short- 

 tongued bees) and the ApidcB (Long-tongued bees). In provisioning 

 their nests with honey or pollen, or both, which they collect from flowers, 

 bees are of great economic importance in the cross-fertilization of many 

 flowers. (See Part I.) 



Most of the AndrenidcB are miners and make their nests in the 

 ground. They are solitary, each female making her own nest, but 



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