Caryomyia asteris Gagne, new species

Hosts: Carya tomentosa, ovata

Gall (Figs. 32, 100-101): Rare, on Eucarya hickories, not found east of the Appalachian Mountains or Ohio, except for one specimen from near the South Carolina Coast; on lower leaf surface, between veins; 2.0-2.5 mm in height, short-obconic, the apex almost flat, expanded laterally into flat, circular, horizontal disk with raggedly serrate edge, with small, central umbo at apex usually still bearing thin, circular, disk (the ephemeral cut-out leaf lamina beneath which gall issued; easily detachable and often no longer present) equal to more than 1/3 expanded gall diameter; surface covered with fine, short, brown hairs not obscuring gall surface; base tapering to small, conical pedicel, leaf with some irregular exfoliation surrounding connection with gall and showing discolored, slight convexity on reverse side of leaf; wall thin, becoming brittle, larval chamber glabrous, longitudinally striate. The architecture of this gall is generally similar to that of C. inanis except that the extraneous tissue surmounting the larval chamber is disposed horizontally rather than vertically and is more papery in C. inanis.

Affinities. — See under C. inanis. [C inanis: This species and C. asteris are similar for their fusiform larvae with raised, but asetose papillae. An important difference between the two is the presence in only C. asteris of setae on the dorsal and pleural papillae of the second instar. Galls of the two also are generally similar, the main difference being that the exfoliate part of the gall beyond the larval chamber is vertical and continuous in C. inanis but horizontal and starlike in C. asteris.]

Range: IL, IN, MS, OH

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

Reference: https://www.biodiversitylibrary.org/page/38636615#page/28/mode/1up