Caryomyia arcuata Gagne, new species

Hosts: Carya tomentosa, texana

Gall (Figs. 141-142): Rare, on Eucarya hickories; found singly on lower leaf surface between veins; 2.5-2.7 mm high, base lunulate, its sides flared toward apex and surrounding base of central, apically pointed cone; hairless, not sticky, brown to purple; base with shallow, central excavation; larval chamber located at base of gall, ovoid, lined with yellowish membrane, contrasting with brown to purple, large-celled, spongy, viscous tissue surrounding larval chamber, a bundle of longitudinal fibers present between larval chamber and gall apex. This gall shows some resemblance to that of C. sanguinolenta from which it differs in the sides of the gall being conspicuously flared upwards around the apical cone.

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, FL, IL, LA, MO, SC

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

Reference: https://www.biodiversitylibrary.org/page/38636615#page/31/mode/1up