34 



SIXTH ANNUAL REPORT 



Type Gall.i:cola or Gall-inhabiting. — The gall or excrescence 

 produced by this insect is simply a fleshy swelling of the under side 

 of the leaf, more or less wrinkled and hairy, with a corresponding de- 

 pression of the upper side, the margin of the cup being fuzzy, and 

 drawn together so as to form a fimbriated mouth. It is usually cup- 

 shaped, but sometimes greatly elongated or purse-shaped (Fig. 3, «, h). 

 Soon after the first vine-leaves that put out in the spring have 

 fully expanded, a few scattering galls may be found, mostly on the 



lower leaves, nearest the ground. 



These vernal galls are usually 



large, (of the size of an ordinary 



pea,) and the normal green is 



"' often blushed with rose where 



exposed to the light of the 



sun. On carefully opening one 



of them (Fig. 4, d) we shall 



find the mother-louse diligently 



>r) at work surrounding herself 



•^/^ with pale-yellow eggs of an 



elongate oval form, scarcely .01 



inch long, and not quite half 



uivDKK SIDE OF lraf coykkkd wiTu galls. rs thlck (Fig. 4, c')- She is about 



.04 inch long, generally spherical in shape, of a dull orange color, and 



looks not unlike an immature seed of the common purslane. At 



times, by the elongation of the abdomen, the shape assumes, more or 



less perfectl}', the pyriform. Her members are all dusky, and so short 



[Fig. 3.] compared to her swollen body, that she appears very 



clumsy, and undoubtedly would be outside of her 



gall, which she never has occasion to quit, and which 



^^^fe]-^!'; I ^ serves her alike as dwelling house and coffin. More 



carefully examined, her skin is seen to be shagreened 



c and rf, upiK 1- and or mmutoly granulated and lurnished with rows ot 



under side ol' iilior- '. ... .n. «. -ii c :t 



five galls. minute hairs, which will be more particularly reierrea 



to in the appendix. The eggs begin to hatch, when six or eight days 

 old, into aclive little oval, hexapod beings, which differ from their 

 mother in their brighter yellow color and more perfect legs and an- 

 tenna3, the tarsi being furnished with long, pliant hairs, terminating in 

 a more or less distinct globule. These hairs were called digiiuli by 

 Dr. Shimer, and tliey lose their globular tips and become more or less 

 worn with age. In hatching, the eg,g splits longitudinally from the 

 anterior end, and the young louse, whose pale yellow is in strong con- 

 trast with the more dusky color of the egg-shell, escapes in the course 



