Caryomyia albipilosa Gagne, new species

Hosts: Carya tomentosa, glabra, cordiformis

Gall (Figs. 39-40): Common, a spring gall, on both Apocarya and Eucarya hickories; found singly or in groups on lower leaf surface between veins; 3.5-5.0 mm in height, elongate-conical, narrowing gradually from base to pointed apex; surface whitish green, eventually turning brown, obscured except at apex by white hairs longer than gall diameter; gall base shallowly concave; wall uniformly thin, becoming brittle; larval chamber rough with weak longitudinal ridges. This gall differs from that of C. striolata only in having a thick covering of long, white hair.

Affinities. — Except for the presence of white hair covering the gall, I can detect no difference between this species and that of C. striolata. These are the only strictly spring-occurring galls in this genus. That the galls of these two species appear in spring and dehisce soon after further separates them from remaining Caryomyia spp.

Biological notes. — In central Maryland this species is one of two spring galls with larvae developing between late April and early June. A series of adults emerged from caged previous year's galls on 16-18 April when hickory leaves were unfurling. A specimen of Lestodiplosis, a predaceous cecidomyiid, was reared with this series of adults. Very small, unidentifiable galls were evident on May 17, 2005. Circled with a marker, these traces were full-grown galls of C. albipilosa with full-grown larvae on May 24. Galls still on the leaves after mid-June are parasitized or contain dead larvae. See under C. striolata for more details on timing of galls.

Range: CT, MD, NY, VA, DC, WV