HYMENOPTERA: CYNIPSERA. 377 



nearer to the back than usual ; the ovipositor straight 

 and often exserted ; hind legs longest ; antennae filiform 

 or setaceous, and thirteen or fourteen jointed. 



CYNIPSERA, Latr., OR GALL-FLY FAMILY. --This Fam- 

 ily comprises small hymenoptera which have the head 

 short and broad, thorax thick and oval, abdomen much 

 compressed and attached to the thorax by a very short 

 peduncle, and the wings few veined. The females have 

 a long, slender ovipositor, with which they insert their 

 eggs into leaves and other parts of plants. These punc- 

 tures cause excrescences called galls, the form and solidity 

 of which vary according to the nature of the plant or 

 parts of the plant that receive the wounds, and according 

 to the species of gall-fly that make them. The eggs in- 

 troduced into the punctures increase in size, and at length 

 hatch, and the larvae feed upon the vegetable matter in 

 which they find themselves imbedded. With some ex- 

 ceptions, they undergo their transformations within the 

 galls, and, gnawing through the shell, fly away. Some 

 species gnaw through at the end of their larval life, and 

 enter the ground to go into the pupa state. There are 

 members of this family which produce no galls themselves, 

 but are parasitic in galls produced by others ; and they 

 are called Guest Gall-Flies. 



The Genus Cynips comprises those species which attack 

 Oaks, and Rhoditcs those which are confined to the Rose. 

 The nut-galls of commerce, used in making ink, in color- 

 ing, and in medicine, are caused by the punctures of gall- 

 flies on a species of oak growing in Fig 

 Western Asia. The Rose-bush Gall- "N T 

 Fly, R. dichloccnis, Harr., about one 

 eighth of an inch long, is bred in 

 great numbers in the woody galls or 



long excrescences of the stems of rose- 

 bushes. Rose-bush Gall-Fly. 



