Caryomyia marginata Gagne, new species

Hosts: Carya texana, ovata, tomentosa

Gall (Figs. 139-140): Infrequent, on Eucarya hickories; on lower leaf surface, between or on veins; length 3.2-5.0 mm, conical, the base flat against leaf surface, circular, with flattened lip surrounding cone that gradually and evenly narrows to pointed apex; green to tan, smooth, covered evenly with long, sparse hairs not obscuring surface; base with narrow, shallow, circular, central excavation, the leaf without exfoliation surrounding connection; larval chamber ovoid, located at base of gall, surrounded by woody tissue. This conical, sparsely haired gall is most similar to that of C. conoidea but the sides of the cone of the C. marginata gall are concave and the basal angle is acute and marginate. This gall is entirely woody unlike that of C. conoidea, which is partially filled with soft tissue that eventually collapses.

Affinities. — See under C. sanguinolenta, from which this species differs in the shape of the gall. [C sanguinolenta: Galls of this species resemble closely enough those of several other species, C. biretta, C. conoidea, C. lunata, C. marginata, and C. stellata, to indicate some relationship among them, given other similarities of adult and larval characters. These species differ only in the shape of their galls, which are conical with their extensive soft, large-celled tissue eventually collapsing. Between that tissue and the larval cell is a pellicle that is at first soft but eventually hardens into a brittle covering. The soft tissue mostly deteriorates during the winter. The base of the galls, through which pupae eventually escape, is shield- like and smooth, even on otherwise hairy galls. The conical galls only superficially resemble those of C. persicoides and C. turbanella. Galls of these last two deteriorate differently and pupae break out of the side of the gall rather than the base. Also, the male antennae and genitalia of these two species place them in another group.]

Range: AL, AR, CT, KY, ME, MA, MS, MO, NH, NY, OH, Ontario, WV

- Raymond J. Gagne: (2008) The Gall Midges (Diptera: Cecidomyiidae) of Hickories (Juglandaceae: Carya)^©

Reference: https://www.biodiversitylibrary.org/page/38636615#page/61/mode/1up