Celticecis cornuata Gagne, new species

Hosts: Celtis laevigata, occidentalis, tenuifolia

Gall.--On major vein, usually on lower surface of leaf; upright, elongate-cylindrical, unevenly tapered beyond 2/3 length to rounded, weakly recurved apex; basal margin irregularly angled; surface glabrous, hairless, slightly furrowed, visible longitudinal veins slightly spiraling; green, usually turning red; 6–7 mm in length and up to 2 mm wide; connection to vein a prominent, circular, flat, persistent brown callus at least as wide as gall base; gall apparent on opposite side of leaf as slight thickening of vein; wall thin throughout, larval chamber of same shape as gall.

Affinities.--The prominent callus that remains on the leaf after the gall dehisces is reminiscent of that seen in some stem galling species, e.g. C. ramicola.

Biological notes.--Galls were first noticed in Louisiana on March 26 on partially expanded leaves. Galls are usually green when young and turn red with age. Full grown larvae were present in late April in Temple, Texas and in mid to late May in Alexandria and Pineville, Louisiana. Any galls still found attached to the leaves later than May 30 contained either a dead larva or a parasitoid, so the larva had presumably stopped feeding before an abscission layer was formed that would have allowed the galls to dehisce.

Distr.-- This species has a southerly U.S. distribution on sugarberry, northern hackberry and dwarf hackberry.

AR, FL, GA, KY, LA, MO, TX

- Raymond J. Gagne, John C. Moser: (2013) The North American Gall Midges (Diptera: Cecidomyiidae) of Hackberries (Cannabaceae: Celtis spp.)^©

Reference: https://www.biodiversitylibrary.org/page/51467028#page/28/mode/1up