1052 Wattrer 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 
ia. 102. LEAVES OF CRAETAEGUS 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 
