Caryomyia spinulosa Gagne, new species

Hosts: Carya cordiformis

Gall (Figs. 92-93): Occasional, known from bitternut of the Apocarya section; found singly or in small groups, attached to leaf vein, usually on lower leaf surface, occasionally on upper leaf surface; 6.2-8.0 mm in length, recumbent, base bulbous, tapered beyond into elongate, usually abaxially bowed extension with pointed apex; green, yellow, to tan, covered with short, white, downy, crinkled hairs not obscuring surface; base of gall with central conical pedicel in shallow circular indentation; wall firm, brittle, uniformly thin, larval chamber glabrous with longitudinal ridges following gall axis from leaf vein connection to apex. This gall is superficially similar to those of C. procumbens and C. supina. It is known only from bitternut, while those of the other two occur on the Eucarya group, except for one known exception in C. supina. The gall of C. spinulosa has hair, as does that of C. procumbens, but the hair on the gall of C. spinulosa is downy and crinkly rather than stiff and straight and the gall base is much more bulbous. The gall of C. supina is hairless and not bulbous basally.

Affinities. — Caryomyia spinulosa is one of the three Caryomyia spp. restricted to bitternut. This species and the other two, C. cilidolium and C. ansericollum, each appear most closely related to species found on the Eucarya group and not to one another. For further discussion of C. spinulosa, see under C. eumaris. [C eumaris: Galls of several other species, C. procumbens, C. recurvata, C. spinulosa, and C. supina, have similar attachments to leaf veins, grow horizontally, are thin-walled but brittle, and have longitudinally ridged larval chambers. Larvae of all are generally similar with narrow but two- toothed spatulas and only four dorsal papillae on each abdominal segment. The adult stage has been reared for only two species of this group, the female for C. eumaris and the male for C. recurvata.]

Range: AR, IN, MD, MA, MO, PA, NY, VA, WV