NATURAL HISTOKY, TOEONTO KEGION 



Hormaphis hamamelidis, Fitch, and Hamamelistes 

 spinosus,Shimer, are common on the witch hazel near 

 the city. The former is a conoidal leaf gall, while 

 the latter is a somewhat elliptical spiny structure 

 originated from a flower bud. 



Pemphigus vagabundus, Walsh, is a very con- 

 spicuous gall at all seasons of the year on cottonwood, 

 Populus deltoides, Marsh. The leaf petioles of the 

 same host are often twisted and enlarged by Pem- 

 phigus populicaulis, Fitch. 



Colopha ulmicola, Cockscomb-elm gall, Fitch, is 

 not uncommon. It deforms the leaves of the Ameri- 

 can elm, Ulmus americana, L. 



Four species of Chermes affect the spruces of this 

 region, namely, Chermes able t is, Choi., on Norway 

 spruce (Picea abies, Karst) and Black spruce (Picea 

 mamma, B.S.P.), and Chermes floccus, Patch, Chermes 

 similis, Gill., Chermes pinifoliae, Fitch, on Black 

 spruce. 



Order LEPIDOPTEEA. 



These galls are produced almost invariably as a 

 spindle-shaped swelling of the stem of the host. They 

 are so conspicuous on account of their size that they 

 often attract attention. 



Eucosma scudderiana, Clemens, on the golden- 

 rods, Solidago canadensis, L., and Solidago serotina 

 var. gigantea, Gray (seldom). This gall occurs high 

 up on the stem of the host among the branches. The 

 196 





