Caryomyia conoidea Gagne, new species

Hosts: Carya glabra, ovata, tomentosa, laciniosa

Gall (Figs. 137-138): Occasional, on Eucarya hickories; single or in groups, on lower leaf surface between veins; height 3.8-5.0 mm, generally conical, edge at base rounded, base adjacent to leaf uniformly hard, conical and often with cylindrical extension at apex, sides developing longitudinal ridges and furrows upon maturity; green to red or brown surface smooth, with sparse, short, erect, white to tan hairs not obscuring surface; base with central, circular, shallow depression, leaf with short, irregular exfoliation surrounding basal connection to gall; larval chamber basal, depressed-ovoid, lined with yellowish membrane, contrasting with brown to purple, large-celled, spongy, viscous tissue surrounding larval chamber that shrivels with age and traversed by bundle of fibers between larval chamber and gall apex. This gall is most similar to that of C. sanguinolenta, q.v. for remarks.

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.]

Biological note. — In spring the pupa emerges from the base of the gall (as in Fig. 136).

Range: CT, KY, ME, MD, MA, NH, NY, NC, OH, Ontario, PA, DC, WV

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

Reference: https://www.biodiversitylibrary.org/page/38636615#page/40/mode/1up