Caryadiplosis biconvexa Gagne, new species

Hosts: Carya ovata, glabra, cordiformis, tomentosa, aquatica

Gall (Figs. 33, 167-169): Common, on both Eucarya and Apocarya sections; circular swelling, ca. 3.5 mm in diameter, on lamina, showing on both sides of leaflet; similar in color and texture to leaf, but some mature galls may turn black before larva escapes; wall of uniform thickness, larval chamber circular, flattened, reflecting gall shape; full-grown larva exits gall from small hole in center of gall on abaxial leaflet surface.

Affinities. — The larval terminal segment has dorsal verrucae in contrast with the smooth preceding segments. This is an effective character for separating this species from C. venicola. The two species are further separated by the terminal papillae all being situated on lobes in C. biconvexa and the lack of such lobes on C. venicola.

Biological notes. — Small circular galls with first instars were found as early as May 26 in central Maryland. On both June 5 and 9 yellow galls were found with full grown larvae or from which larvae had already escaped, indicating that development is swift. Possibly this species has more than one generation per year because galls with first instars were found as late as Sept. 11 and second and third instars on Sept 26, but the galls seemed not as common in late summer as in spring. Larvae exit from the lower surface of the leaflet.

Range: AL, AR, GA, IN, MD, MA, NY, NC, OH, OK, PA, TN, DC, WV

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

Reference: https://www.biodiversitylibrary.org/page/38636615#page/95/mode/1up