60 REPORT OF No. 19 



Eriophyes pyri. Produces blister-like swellings on the leaves of the 

 Pear and Apple. The blisters are reddish brown in May, green in June, and 

 dark brown or black in the latter part of June. The blisters usually run 

 together, forming irregular blotches over the upper surface of the leaf. Oc- 

 curs on Pear (Pyrus coTmnunis) and Apple (Pyriis mains). Very common. 



Eriophyes sp. This gall is green and red and about 2 cm. in length. 

 It consists of a fold of the leaf making a long, irregular, wavy projection 

 on the upper surface of the leaf. From beneath this appears as a serpentine 

 incision in the leaf. It is about 2 m.m. high. It is hard and roughened on 

 top. From the midrib to the edge of the leaf is the general direction of the 

 gall. Occurs on Hawthorn (Crataegus sp.). Common. 



Eriophyes sp. Produces galls about 2.5 m.m. in length by 1.5 m.m. 

 broad. It is joined to the leaf by a constriction. Externally it is red and 

 pubescent. Inside gall is full of granular material and contains numerous 

 mites. Occurs on Speckled Alder (Alnus incana). Common, especially upon 

 the leaves of the bushes at the water's edge. 



Eriophyes sp. This mite produces galls of the typical Eriophyid shape 

 upon the leaves of the Paper Birch. The galls are yellowish or reddish, 

 joined to the leaf by a constricted neck and rather smaller than usual, being 

 about 2 m.m. long by 1 m.m. broad. They appear on both upper and under 

 sides of the leaf, and when found upon the under side, hairy. The opening 

 on the opposite side through the leaf lined with white hairs. 



Parasitic mites attack this species and often they are found to have 

 devoured or driven out all of the gall makers. Occurs on the Paper Birch 

 (Betula papyrifera). Common. 



Eriophyes salicola Garman. The gall is irregular, roundish and ser- 

 rated, with a roughened top, projects about 1.5 m.m. from the surface of the 

 leaf, slightly constricted where it joins the leaf. From 1-4 m.m. in dia- 

 meter. On the under side there is sometimes a small projection and some- 

 times a cup-like cavity in which are seen the roughened portions of the 

 under side of the gall. When the gall is mature, it is filled with granular 

 excrescences and hairs growing from the interior walls. The gall is green 

 or red and distributed over the upper or lower surface of the leaf. Occurs 

 on Salix Alba, Salix halsaviifera, Salix discolor, Salix rostrata. 



The description was taken from Galls on Salix balsamifera. 



Eriophyes sp. This mite produces dimples on the leaves of the Aspen 

 on the upper side lined with spherical granules, reddish or greenish in color. 

 These consist of soft parenchymatous tissue upon which the mites feed. The 

 galls are fairly uniform in size, being about 2 to 3 m.m. in diameter. The 

 galls are green in color and occur three or four to a leaf. Occurs on Aspen 

 (Populus tremuloides) . Common. 



Eriophyes sp. The galls consist of irregular projections on the upper or 

 under side of the leaf and are quite generally distributed in patches, 4-5 

 m.m. in length or even 1.5 cm. They project about 1-1.5 m.m. above the 

 leaf. On the under side they appear as irregular cavities lined with white 

 vegetable hairs. The galls are green in spring, turning red later in the sea- 

 son. Occurs on Poison Ivy (Bhvs toxicodendron). Common. 



Eriophyes sp. This gall consists of a small circular depression averag- 

 ing about 2 m.m. in diameter and always depressed on the lower side of the 

 leaf. On the upper side it appears as a green or red circular elevation. The 

 gall is lined with minute spherical granules composed of soft parenchy- 

 matous tissue. Occurs on large-toothed Aspen (Populus grandidentata). 

 Common. 



