Celticecis expulsa Gagne, new species

Hosts: Celtis laevigata, occidentalis

Gall.--On stem, fruit, petiole and base of leaves; irregularly columnar, apically convex or flat, usually with short, central nipple, sometimes 2–3 galls partially coalesced, strongly convex on opposite side of petiole or vein and usually causing leaf distortion; base broad, integral to host tissue, developing apically a circular mark at apex, denoting margin where inner portion of the gall will emerge as a plug from the periphery and dehisce, the remainder of the gall shriveling; green, matte, with sparse white pubescence; 5 mm high, 3 mm broad; the deciduous plug yellow except for green apex, turning brown, larval chamber ovoid, the wall of the plug of uniform thickness.

Biological notes.--The gall of this species is the only one in North America that is not entirely detachable. Initially it appears as a simple columnar elevation of the plant tissue but eventually the interior of the gall surrounding the larval chamber separates as a distinct, hard, cylindrical core (Fig. 21). In due course the outer tissue shrivels, allowing the core to drop to the soil. In Alexandria, Louisiana, and Holland, Texas, galls were evident in early April, already with second instars. Most galls had dehisced by mid-May wherever the gall was found. Adults were reared in March and April, 2011, from galls taken in June, 2009, in Lawrence, Kansas.

Distr.--Galls were found on both northern hackberry and sugarberry. This species may be more widespread than the distribution list indicates, but galls develop and excise earlier in the season than most of our collections were made.

KS, KY, LA, MD, TX, WV

- 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/30/mode/1up