Caryomyia hirtiglobus Gagne, new species

Hosts: Carya tomentosa, pallida, glabra, texana, ovata

Gall (Figs. 53-54): Occasional, found on Eucarya hickories; single or clustered, on lower leaf surface between veins; 2.5-3.0 mm in height, depressed-spherical, occasionally weakly conical apically; covered with short, thick, brown hair obscuring gall surface; base of gall at center with short, conical pedicel at center of circular indentation, the corresponding leaf connection surrounded by inconspicuous exfoliation of the leaf; wall firm, brittle, uniformly thin except slightly thicker at apex; larval chamber of same shape as gall, without conspicuous extension into basal pedicel, glabrous, green to purple, with longitudinal ridges. In outward appearance the gall of this species is generally similar to those of other spherical, hairy galls, especially those made by C. purpurea and C. holotricha, but when cut longitudinally, the gall's uniformly thin wall and its conical connection to the leaf will serve to distinguish it from otherwise superficially similar galls.

Affinities. — This species forms a natural group with C. caryae and C. shmoo because of the general shape of the gall. See under C. caryae for further discussion. [C caryae: As mentioned in the gall description, two intergrading kinds of galls are formed by C. caryae as defined here (compare Figs. 55-56 with 57-58). This species is apparently related to C. hirtiglobus and C. shmoo because of the general conformation of the gall with its acute-conical connection to the leaf.]

Biological notes. — Galls of various sizes were first noticed on June 16 in central Maryland, with first instars in the smaller galls, second instars in the larger. The hair covering the gall is at first white, turning to brown by the time the gall is full size. Galls cut open on July 27 contained either second or third instars, both instars very active when touched. Their ventrally situated heads are closely appressed to the gall tissue so that the leading edge of the larva as viewed dorsally is the prono- tum. Small specimens of third instars seen on August 19 were closely appressed to the curved gall interior. By mid-September fully-developed third instars are opaque white and stout with expanded segments, and are no longer so closely appressed to the larval chamber surface.

Range: AL, AR, CT, FL, GA, KY, MD, MA, MS, MO, NY, NC, OK, TN, VA, DC, WV

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

Reference: https://www.biodiversitylibrary.org/page/38636615#page/50/mode/1up