INSECT-GALLS OF THE VICINITY OF NEW YORK CITY 



19 



oval, covered with numerous, rather long spines. Length about f in. Yellow 

 or greenish yellow with the spines bright red, especially when young. On one 

 of the principal veins of leaf of white oak {Qiiercus alba). Common. 



36. Oak Fig Gall {Biorhiza forticornis Walsh). — Consists of many small, 

 soft, bladder-like bodies, each containing a single cell, which is held in position 

 by radiating fibers. They are closely pressed together and somewhat resemble 

 figs packed in boxes, — hence the name " Fig Gall." Pale yellow, often beauti- 

 fully tinged with bright red. Brown in winter. On twigs of white oak {Qiier- 

 cus alba). Common. 



37. Oak Bullet Gall {Holcaspis globulus Fitch). — Bullet-like, corky, with a 

 small cavity in the center containing a single larva living in an oval, whitish 



