Caryomyia tumida Gagne, new species
Hosts: Carya ovata, tomentosa
Gall (Figs. 104-105): Rare, known from only 2 collections, on Eucarya hickories; on lower leaf surface, between veins; 3 mm in height, depressed-obconic, with small umbo at apex, made up of basal ovoid larval chamber and apical, much broader, false chamber; tan, rubbery, covered with short, decumbent hairs obscuring gall surface, not sticky; base of gall tapered to conical pedicel, leaf with slight exfoliation around gall connection forming short, tubular socket and on reverse side showing discolored convexity; wall thin, basal larval chamber separated from larger, apical false chamber by thin wall with umbo at center, both chambers longitudinally striate. The gall is shaped as for that of C. inflata but is covered with decumbent hairs in contrast to the completely hairless, glabrous gall of C. inflata.
Affinities. — See under C. inflata. [C inflata: This species and C. tumida come from similarly shaped, two-chambered galls, but that of C. inflata is smooth, the other thickly covered with short, decumbent hairs. Beyond that, the galls have certain similarities to that of C. asteris. Although the latter gall is not two-chambered, second instars of all three species have setose dorsal and pleural papillae. The rays of the C. asteris gall may indicate some midpoint development of a strictly two-chambered gall.]
Range: IL, PA
”- Raymond J. Gagne: (2008) The Gall Midges (Diptera: Cecidomyiidae) of Hickories (Juglandaceae: Carya)©
Reference: https://www.biodiversitylibrary.org/page/38636615#page/88/mode/1up