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Indiana University Studies
KEY TO DESCRIBED CYNIPS
DIAGNOSTIC CHARACTERS OF AGAMIC FORMS. Usually rather large and robust insects with the mesonotum punctate and more or less hairy, usually with complete parapsidal grooves, an undivided or finely divided foveal groove, a hypopygial spine which is large and distinctly broadened nearer the tip (except in short-winged Acraspis) and which terminates in a prominent tuft of long hairs; tarsal claws which are strongly or at least weakly toothed (except in mellea) ; wings long or much reduced, the long wings 1.17 to 1.60 times the body length, the short wings of various lengths down to 0.14 times the body length; the long wings usually with a smoky patch at the base of the cubital cell, sometimes with additional spots or smoky patches in this and other cells. Living (with a few exceptions) in monothalamous, highly separable leaf galls which are usually spherical, with the centrally placed larval cell closely embedded in dense, radiating fibers or more solid, spongy or crystalline material, the galls in some cases of more diverse form, especially in the subgenus Antron. Strictly confined to white oaks. Galls appearing in early summer, the adults maturing early in the fall, but delaying emergence until cold weather, from early winter to early spring of the first year (and successive years in C. fulvicollis).
DIAGNOSTIC CHARACTERS OF BISEXUAL FORMS. More slender insects, with the mesonotum largely smooth and naked, the hypopygial spine as in the agamic form but more slender; tarsal claws toothed; wings always long, 1.17 to 1.60 times the body length, less heavily spotted than in agamic forms; the males with one more antennal segment than in the female, with the third segment slightly curved, and with the abdomen long-petiolate. Galls always small, seed-like or bladdery, thin-walled cells in the undeveloped buds of the white oaks. Galls appearing with the opening buds in the spring, the adults maturing within a very few weeks.
| 1. | Wings always 1.50 times the body length, cells always clear (except fora trace of a blotch at base of cubitus); hypopygial spine rather broad, rather drawn out ventrally. Entirely Old World species.Subgenus Cynips, 4 |
| Wings from 0.14 to 1.60 times the body length, wing cells clear or spotted, spines various. Entirely American species.2 | |
| 2. | Hypopygial spine rather broad, but drawn out ventrally (see figs. 175-190); wings normally 1.60 times the body length, or much reduced in length; with a heavy patch and sometimes spots in cubital cell. Pacific Coast species not known east of the Sierras except in southern Arizona.Subgenus Antron, 7 |
