Caryomyia aggregata Gagne, new species

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

Gall (Figs. 21a-b, 156-157): Common, on most Eucarya hickories; on lower leaf surface on vein, usually clustered in a row along major vein and often in such close aggregation as to partially coalesce; 3.0-5.0 mm in height, spheroid to bilaterally compressed, sometimes pointed at apex, when coalesced bearing two or more larval chambers in an apparently single gall; covered with thick, mostly brown hair obscuring gall surface; base with small, irregular, shallow, central to off-center excavation; wall woody, thick, especially above, larval chamber irregularly ovoid, glabrous, green to brown. The gall of this species can be confused with several other spheroid- conical, densely hairy galls, but its position along the major veins and usual crowding sets it apart from galls of the other species, e.g., C. holotricha and C. purpurea. Galls were described in Osten Sacken (1862) as a variant of typical galls of C. holotricha, but galls of the latter always have an apical intrusion of hairs in the larval chamber and occur between instead of on the veins.

Affinities. — The closest relative of this species among the C. caryae species group is not apparent. Galls of this species and those of C. guttata are the only ones known to grow so closely together, coalescing at times.

Biological notes. — Small, tan, white haired galls in tight or loose rows along midrib were found with first instars in central Maryland on May 26. In mid-June galls were full-sized with second instars. In mid-July, third instars could be found but until mid- August most galls contained second instars. By late August all galls contained third instars.

Range: AL, AR, CT, FL, GA, KY, IN, IL, MD, MA, MO, NH, NY, NC, OH, PA, 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/26/mode/1up