On leaf, blister-like, irregularly circular in outline, 2½-3½ mm.
diameter, ½ mm. thick. Extends above and below about equally. Sometimes
a slight central nipple is formed below. Greenish to brownish with
discolored margin.
Collected in Vinton County, Ohio, on _H. cordiformis_.
Probably same as Felt’s “Leaf blister gall, irregular, dull greenish or
black margined with small nipple. Diameter 3mm.”
This type of gall is so different from all the other cecidomyid forms
that it is doubtful if it is a member of that group. It may possibly
be an immature or small Phylloxera gall. The writer found white larvæ
within his specimens, but was unable to determine them as cecidomyid
larvæ. This gall is thus introduced here, provisionally.
Felt, Jour. Econ. Ent. 4:456. 1911.