Caryomyia spiniglobus Gagne, new species

Hosts: Carya tomentosa, glabra, laciniosa, ovata

Gall (Fig. 64-65): Common, on Eucarya hickories; single or in groups on lower leaf surface between veins; 2.8-3.5 mm in height, spherical with a conspicuous apical terminus made up of a nipple atop an abruptly raised areola; green to yellow, becoming tan to brown with widely spaced, short, stiff light brown hairs not obscuring surface; base with small conical pedicel, leaf without exfoliation; wall firm, brittle, uniformly thin, larval chamber glabrous with longitudinal ridges. This gall differs from that of C. leviglobns in that it has hair. Both galls are distinctive for the raised apical knob.

Affinities. — See under C. leviglobus, from which the present species differs only in the hairy galls. [C leviglobus: This species does not differ from C. spiniglobus except in the exterior of the gall that is smooth in C. leviglobus and stiff-haired in C. spiniglobus. I found galls of both species at the same site, but not in proximity on the same leaflet, so consider them separate species. While C. leviglobus is more common than C. spiniglobus, both are generally widespread. As with other species (viz. the C. caryae and C. cilidoliurn groups) that live unconstrained in a rather large, spherical larval chamber, the integument is completely covered with spiny verrucae that evidently allow these species purchase in crawling across the curved surface of the larval chamber.]

Biological notes. — Tiny, soft, whitish galls with first instars were first noted in central Maryland on June 9. In mid-June to mid-July soft galls could be found mixed with hard, brittle galls, the former with first, the latter with second instars. By beginning of August galls were regularly found with third instars. Feeding larvae lie prone against the concave surface of the larval chamber.

Range: AL, AR, CT, FL, GA, KY, LA, MD, MA, MS, NJ, PA, SC, 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/74/mode/1up