Rhopalomyia clarkei

Rhopalomyia clarkei is a species of gall midges, insects in the family Cecidomyiidae. The larvae induce galls on two hosts: Solidago altissima and Solidago rugosa and are found in north-eastern and north central North America.

Galls and Biology
The galls are small, conical, and single-chambered, and typically occur on the lower side of leaves but sometimes on the upper side of leaves and on stems. Each gall contains a single white larva and is attached to either a major or minor vein when on leaves. On Solidago rugosa, the galls are 2.5-6 mm long and .7-1.2 mm wide at the widest part, tapering toward the apex, green to yellowish green, and covered by short, whitish hairs. Young galls may sometimes have a tuft of hair at their base, almost as long as the gall itself.

The adult female is 2 mm long with a dull red abdomen and 17 antennal segments.