Atrusca strians (Kinsey, 1930)

Figs 558–571

Synonymy
Cynips centricola variety strians Kinsey, 1930: 304, female, gall.
Cynips (Atrusca) (centricola) strians Kinsey, 1936: 181.
Atrusca strians (Kinsey): Weld 1951: 638.

Types examined

HOLOTYPE female Cynips strians var. centricola “Bonnie, Ill. Gall 10.15.27”, “Q. alba, Kinsey coll.”, red “Cynips strians, Holo- Paratype”, deposited in AMNH, NYC, examined by GM.
Seven PARATYPE females “Morelia, 14E, Mich 7000’, Mex., galls 12.27.31, 234 females 3.22.32.”, “Q. conglomerata Kinsey coll.”, red label “Cynips spinifera Paratype”, deposited in the general collection in AMNH, NYC, examined by GM.

Gall (Fig. 571)

The gall is similar to all galls of Kinsey’s bella and dugesi complexes. Mature galls globular, always well spotted, brownish purple.

Biology

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

Distribution

USA: Illinois.

Cynips (centricola) strians Kinsey
agamic form

Cynips centricola strians Kinsey, 1930, Ind. Univ. Studies 84-86:304, figs. 48, 256-257, 286 (omitting Eddyville record).
Cynips quercus-centricola strians Houard, 1934, Marcellia 28:47.
Cynips quercus-centricola Houard, 1935, Marcellia 28:122.

To the data given in Kinsey 1930, add:

RANGE.-Missouri: Springfield, 7 SE (R. Voris in Kinsey coll.). Norwood, 5 E. Sullivan, 1NE. Winona. Arkansas: Imboden, 5 SW (gall, B. C. Marshall in Kinsey coll.). Busch, 4 E. Sheridan, 4N. Prairie Grove, 4 E. Conway, 4 E. Hazen, 5 E. Jasper, 4 S. Oklahoma: Muldrow, 2W. Eldon, 4 E (gall only). Louisiana: Wyatt (gall only).

LIFE HISTORY..—Pupae: October 10. Adults: November 26. December 6, 10, 12, 13, 20, 22, 24. January 5, 30. February 2. Most of the emergence in mid-December.

The new records show the extensive range of this species through the Ozarks of Missouri, Arkansas, and Easternmost Oklahoma. The occurrence as far south as Sheridan, Arkansas (and possibly in Northern Louisiana) suggests that strians may be the same as Karsch's rubrae which came, presumably, from Texas; but it will be well to avoid mistaken synonymy by maintaining the two as distinct for the time being. If material from Eastern Texas, and a study of the type of rubrae (at the Berlin Museum) shows it to be the same as strians, it will be easy enough then to combine the nomenclature and data.

The spotted galls of strians are practically the same as those of centricola, differing perhaps in averaging smaller in diameter. Previously we considered that the well-developed median groove (found in most of the types) would always separate strians from centricola, but the more extended material which we now have from the Ozarks shows so much individual variation in this character that we must depend on the nearly uniform black color and the less triangulate tip of the second abscissa of the radius of strians as the best characters for distinguishing the insects.

Cynips centricola variety strians, new variety

Agamic form
Figures: 48, 256–257, 286

Synonymy
Diplolepis centricola err. det. Weld (in large part), 1926, Proc. U.S. Nat. Mus. 68(10): 23.

FEMALE

Largely black but often with a rufous tinge on the thorax and even more rufous on the head. Median groove almost always well evident for half the length of the mesonotum, deeply cut posteriorly. The tip of the second abscissa of the radius is slightly triangulate but not broadly so as in variety centricola. The marks in the cubital cell are not abundant nor large (Fig. 286).

GALL

Almost always well spotted with brownish purple; occurs on leaves of Quercus stellata (Figs. 256–257).

RANGE

• Illinois: Bonnie (types, Kinsey coll.), Christopher, Norris City, Bloomfield (Johnson County), Eddyville (hybrid with centricola; O. Buchanan in Kinsey coll.)
• Missouri: Annapolis (E. S. Anderson in Kinsey coll.), Arcadia (gall, Kinsey coll.), Ironton and Poplar Bluff (acc. Weld 1926)
• Arkansas: Hoxie (gall, acc. Weld 1926)

Probably restricted to the Ozark areas in Arkansas and Missouri, and to the eastward extensions of that area in Illinois and possibly western Kentucky and southern Indiana (Fig. 48).

TYPES

11 females and many galls. Holotype and paratype females and galls in the Kinsey collection. Paratype females and galls also in the American Museum and the U.S. National Museum. Labelled Bonnie, Illinois; gall collected October 15, 1927; Q. stellata; Kinsey collector.

NOTES

This is the Ozark variety of the species, known from the true Ozarks of Arkansas and Missouri, but, like many other Ozark Cynipidae, it is also common in the hill country of Illinois and expected in western Kentucky and southwestern Indiana, which are geologically related to the Ozarks. The region is bisected by the Mississippi and lower Ohio Valleys, where the Coastal Plain variety centricola also occurs. Since both centricola and strians have similarly spotted galls, material from this region must be determined based on insect characters.

Strians is the only variety of the species which shows a well-developed median groove. Weld found pupae in galls likely of this variety on October 10. Kinsey bred adults on December 10 and 20 (1927).