63O NEW YORK STATE MUSEUM X 



the latter part of September and spins a rude cocoon a short distance 

 below the surface, where it undergoes its transformations. 



Fusiform maple gall 



Eriophycs acericola Garm. 



Slender, fusiform galls are sometimes very abundant on the upper surface of the 

 leaves of sugar maple. 



This gall is very slender, about r / 5 inch in length and tapers at both 

 extremities. It is occasionally rather abundant on sugar maple leaves in 

 the vicinity of Albany. This species has been studied by Professor Gar- 

 man, who states that in five examples of this mite the striae were counted 

 and in three of them numbered 30 and in the other two 28 and 29 

 respectively. The prongs of the featherlike appendage seemed to be three 

 The mite is about .0075 inch. He h? j recorded this species as being 

 abundant in galls collected in Illinois in June. 



Bladder maple gall 



Eriophycs quadripes Shimer 



The small, bladderlike galls of this species, about y IO inch in diameter, are sometimes 

 very abundant on the upper surface of soft maple leaves. 



This trouble is sometimes exceedingly prevalent in the vicinity of 

 Albany, the galls being so numerous on certain trees as to disfigure a very 

 considerable proportion of the foliage. The galls, according to Professc 

 Garman, appear with the unfolding of the leaves in spring, as slight swell- 

 ings of the parenchyma, and as the foliage expands they develop into 

 top-shaped galls on its upper surface. The form varies from discoid to 

 more or less spherical, while occasionally two are fused and have a com- 

 mon opening. The gall is at first of the same color as the leaf, chang- 

 ing later to dull purple or green and afterward becoming the light green of 

 the veins and veinlets, and later changes to purplish, drying up and becom- 

 ing black at the end of the summer. The outer surface is smooth, though 

 the walls are broadly and irregularly impressed. The position of the gall 



