Atrusca clivorum (Kinsey, 1930)

Figs 173–185

Synonymy
Cynips centricola variety clivorum Kinsey 1930: 300, female, gall.
Cynips (Atrusca) (centricola) clivorum Kinsey 1936: 181.
Atrusca clivorum (Kinsey): Weld 1951: 638.

Types examined

HOLOTYPE female Cynips clivorum var. centricola “Coolville, Ohio. Gall 10.24.28, 8 fms. 12.9.28”, red “Cynips clivorum, Holo- Paratype”, deposited in AMNH, NYC, examined by GM. Three PARATYPE females “Coolville, Ohio, galls 10.14.28, 5 females 11.13.28”, “Q. stellata Kinsey coll.”, red label “Cynips clivorum. Paratype”, deposited in the general collection in AMNH, NYC, examined by GM.

Gall (Fig. 185)

The gall indistinguishable from other galls of the complex. The gall is always unspotted.

Biology

The asexual generation is only known to induce leaf galls on Q. stellata. Galls mature in late autumn; adults emerge in November–December.

Distribution

USA: Ohio

Cynips (centricola) clivorum Kinsey
agamic form

Cynips centricola clivorum Kinsey, 1930, Ind. Univ. Studies 84-86:300, figs. 48, 258-259, 269, 285.

To the data given in the above monograph, add:

RANGE.-Ohio: West Union, 6 N. Chillicothe (gall). Gallipolis, 6 N. Indiana: Boonville, 10 E (gall only). Illinois: Eddyville (O. Buchanan in Kinsey coll.). Kentucky: Sullivan, 1W (galls). Tennessee: Dickson, 7W. Jackson 3 S (gall only). Memphis, 12 E (gall only, Breland in Kinsey coll.). Virginia: Golansville

LIFE HISTORY..—Adults: November 2, 13, 20, 26. December 2, 3, 9, 15, 16, 18, 20, 24. January 2. Most of the emergence late in November and early in December.

The new locality records put this Southern Appalachian species, clivorum, at additional points in the Ohio River Valley and in the western third of Tennessee. In the latter state, the distribution extends west to the Mississippi River, which is further west than anticipated. The black insect and unspotted galls make determinations of clivorum practically certain, for all of the other species of the complex have spotted galls (except for rare, unspotted, immature galls in centricola).

Cynips centricola variety clivorum, new variety

Agamic form
Figures: 48, 258–259, 269, 285

FEMALE

Head, entire antenna, and thorax usually entirely black; median groove poorly indicated or absent. The tip of the second abscissa of the radius is enlarged but not triangulate. The marks in the cubital cell are usually much fused (Figs. 269, 285).

GALL

Always unspotted; occurs on leaves of Quercus stellata (Figs. 258–259).

RANGE

• Ohio: Coolville (types, Kinsey coll.), Chillicothe (Kinsey coll.)
• West Virginia: Parkersburg (Kinsey coll.)
• Tennessee: Tazewell, Clinch River near Maynardsville, and Charleston (galls, Kinsey coll.); Tellicoe River near Madisonville, and 9 miles northeast of Chattanooga (includes some hybrids with centricola, Kinsey coll.)
• North Carolina: Hendersonville (includes some hybrids with centricola, Kinsey coll.)
• South Carolina: Travellers Rest (Kinsey coll.)
• Georgia: 6 miles north of Trion, and Rome (Kinsey coll.); Acworth (gall, Kinsey coll.)
• Alabama: Athens (gall, Kinsey coll.)

Probably confined to a limited area on the western side of the Southern Appalachians (Fig. 48).

TYPES

20 females and many galls in the Kinsey collection from Coolville, Ohio; galls collected October 24, 1928; insects emerged November 13 and December 1, 9, 16, and 20, 1928; Quercus stellata; Kinsey collector.

NOTES

Throughout the more southern portion of the Appalachians, from the foothills in southern Ohio southward into Georgia and Alabama, this is the variety of centricola to be expected wherever Quercus stellata occurs. This region is poorly known biologically, and much of its cynipid fauna remains undescribed.

At lower elevations both east and west of the Great Smokies, clivorum appears to hybridize with variety centricola, and such hybridization may be expected wherever the two overlap. Clivorum is distinguished by the insect characters described above and by its consistently unspotted gall. While the gall of variety centricola may also be unspotted when immature, it is typically well covered with bright purplish spots.

Insects of this variety were bred on November 2 and 13, December 1, 9, 15, 16, 18, and 20, and January 2 (all in 1928). Despite the early onset of winter in much of its range, emergence timing is nearly identical to that of centricola and strians, both of which occur in warmer regions.