Cincticornia sobrina

Gall. An inconspicuous, circular, blister enlargement showing mostly on the under surface of the leaf and varying in diameter from 3 to 5 mm.

Adults of this form were first reared by the late Dr M. T. Thompson of Clark University, Worcester, Mass., from a vial containing earth brought into the laboratory for the purpose of. rearing Tineids. It was then thought that they might have come from some seed, possibly elm keys. Subsequent rearings in April 191 1 resulted in obtaining numerous flies, referable with little question to this species, from the leaves of the black oak, Quercus velutina, and probably those of other species, thickly infested with an inconspicuous, circular, blister gall.

Cincticornia sobrina

Irregularly oval, pustulate leaf swelling showing equally on both surfaces but with no nipple, diameter 5 to 6 mm, on Q velutina

Cincticornia sobrina

Flattened, pustulate or blister galls
Reared from a similar gall [to P simpla: An irregularly oval, pustulate swelling, 5 to 6 mm in diameter, showing equally on both surfaces but with no nipple.]

Polystepha sobrina

Circular, flat or convex cell between veins
Smooth, flat or convex, thin-walled cell
Flat and inconspicuous or slightly raised blisters
Gall protruding on both surfaces of leaf

This gall shows mostly on the upper leaf surface.

Host: Quercus velutina

Distr: MA