1052 



WALTER H. WELLHOUSE 



injury is severest in warm, dry periods. The leaves at first become 

 grayish, due to the presence of a fine white web and the cast skins of the 

 mites attached to them. Later they turn brown and their margins curl 

 toward the surface on which the mites have fed. The adults hibernate 

 among the fallen leaves and a few were found in bark crevices on the trunk 

 in April. The tiny, round, white eggs are laid on the leaves. The mites 

 breed continually on the leaves from June to October. 



Eriophyidae 



Eriophyes sp. No. 1 (Hawthorn serpentine gall of Jarvis) 



The species of Eriophyes here described produces long, green or red, 

 serpentine galls confined to the space between two of the larger veins and 

 extending from the midrib toward the margin of the leaf (fig. 102). The 



Fio. 102. 



LEAVES OF CRAETAEGU3 PUNCTATA SHOWING SERPENTINE GALLS 

 PRODUCED BY ERIOPHYES SP. NO. 1 



gall consists of a wavy projection on the upper side of the leaf and a wavy 

 incision on the lower side. In cross section the leaf appears convoluted, 

 with the galls projecting upward as loops or pockets in which the mites 



