"…galls are 3-10 mm long; rounded, elliptical, or elongate-elliptical, depending on the width of the affected leaf; and black, usually with a narrow yellow, white, or purple margin…"

"[on S. microcephala [E. caroliniana] and S. tenuifolia [E. caroliniana]] ...the galls are found on the upper green stems in addition to the leaves… usually completely surround[ing] the stem, as in A. gutierreziae… Unlike for A. carbonifera, the epidermis does not peel off the galls in a layer 1 cell thick. Rather, the epidermis is incorporated with the fungi."

- Raymond J. Gagné: (1968) A Taxonomic Revision of the Genus Asteromyia (Diptera: Cecidomyiidae)^©