Caryomyia inanis Felt

Caryomyia inanis Felt 1909: 292.

Hosts: Carya tomentosa, ovata, laciniosa

Gall (Figs. 8, 98-99): Occasional, on Eucarya hickories, not found east of the Appalachian Mts (Map 2); found singly or in groups on lower leaf surface, between veins; length 2.5-4.0 mm, spheroidal at base with short to long, foliate, papery, lateral extension forming partial false chamber, the distal opening broadly agape to nearly closed; apex of closed part of gall slightly convex with central nipple often bearing thin, horizontal, flat disk (the leaf surface beneath which gall issued) equal to more than 1/3 gall diameter; green to brown with sparse, long, white or brown hairs not obscuring gall surface; base with prominent conical projection in center of circular indentation, leaf with thin exfoliation surrounding gall base; larval chamber ovoid, wall firm, brittle, uniformly thin, smooth with longitudinal ridges. This gall has a similar structure to that of C. asteris, although that is not at first apparent. The foliate extension of the gall of C. inanis is vertical and tubular, while that of C. asteris is horizontally disposed.

Affinities. — This species and C. asteris are similar for their fusiform larvae with raised, but asetose papillae. An important difference between the two is the presence in only C. asteris of setae on the dorsal and pleural papillae of the second instar. Galls of the two also are generally similar, the main difference being that the exfoliate part of the gall beyond the larval chamber is vertical and continuous in C. inanis but horizontal and starlike in C. asteris.

Biological notes. — In mid-June in eastern West Virginia, galls were almost full grown and light green with the exfoliate part still easily pliable and contained second ins tars. In early July, galls were still green but with third instars that were very active when the galls were opened. In August the galls had turned brown.

Range: CT, KY, ME, MA, NH, NJ, NY, OH, PA, TN, WV

Caryomyia inanis n. sp.

was reared April 29, 1909, from an irregular, subglobular, thin-walled hickory leaf gall, 2 to 3 mm. in diameter, and easily recognized by the more or less complete false chamber at the tip of the gall.

Caryomyia inanis

Carya sp.
Globose leaf galls, smooth or nearly so
Thin-walled, with a false chamber at the apex, diameter 2 to 3 mm.

Gall globular, if apex pointed, gall greatly constricted at base, with or without hairs...
Gall smooth...
Gall stalked, spherical, monothalamous...
Gall irregularly spherical, green or brownish, with empty cavity above larval chamber...
Caryomyia inanis Felt