Sphaeroteras unicum

Quercus lyrata, margaretta, stellata
Leaf galls, detachable
Globular, white, up to 7 mm in dia, saddled on a vein on under side of leaf in fall.

[Photo caption]
On Q stellata. Also on Q margaretta, lyrata. Adults emerged the next spring by May 25.

Diplolepis unica, new species

Host. — Quercus stellata.

Gall (fig. 9).- — Spherical, 5-7 mm. in diameter, white, smooth, single, always on under side of leaf saddled on a vein so that when detached a depression (containing pedicel) and groove is left on the gall. Occurs in fall. Monothalamous. A section through a fresh gall shows a white fleshy interior containing a distinct but not free larval cell, a tinge of red or brown just under the outer layer.

Habitat. — The type material was collected at Ironton, Mo., in October, 1917, and adults emerged (in out-of-door cage near Chicago) on May 15, 1918. The writer saw galls at Poplar Bluff also, and at Hoxie, Little Rock, Hot Springs, and Texarkana, Ark; Palestine. Trinity, Cuero, Poerne, Austin, College Station, and Arlington, Tex.: and at Green Cove Springs, Fla. What seems to be the same gall occurs on Q. margaretta and lyrata also. The Pergande collection contained a gall from Virginia and a fly which emerged April 16, 1883, determined as this species.

Cynips mellea variety unica
agamic form

Diplolepis unica
Cynips mellea var E Kinsey

GALL. — As described for the species, becoming white and naked when mature; usually rounded or flattened basally; occurring singly or clustered, on the leaves of Quercus stellata.

RANGE. — Illinois: America, Olney, and Christopher (Kinsey coll.). Missouri: Ironton (Weld coll., types). Arcadia and 6 miles west of Dexter (Kinsey coll.). St. Louis (gall in U.S. Nat. Mus.). Poplar Bluff (acc. Weld 1926). 10 miles southeast of Springfield (R. Voris in Kinsey coll.). Arkansas: Hoxie (galls, acc. Weld 1926). Kentucky: Dawson Springs (Kinsey coll.). Ohio: Chillicothe (Kinsey coll.). Probably centering in the Ozarks of Missouri and more northern Arkansas, but extending eastward into the hills of southern Illinois, Kentucky, and southeastern Ohio. Figure 51.

I found not fully mature galls of unica, which, however, were already dropping from the leaves of the post oaks, in southern Illinois during the second week of October (1927), and in southeastern Missouri and southern Ohio during the last week in October (1926). Live adults were in galls from western Missouri on November 21 (1928) . I have bred adults on December 12, on March 22, during the last week of March, and an April 10. From the galls which Weld collected in Missouri in October, he bred adults at Chicago on May 15, 1918.

The distribution data for this variety are typical for an Ozark cynipid. The hills of western Kentucky and southern Illinois, which are geologically of the same origin as the body of the Ozarks in Missouri and northern Arkansas, contain an interesting extension of the Ozark fauna. The Mississippi Valley in this region has a Coastal Plain fauna. Two of my forty insects of this species from Dexter, Missouri, represent unica , the other 38 being the typical Coastal Plain Carolina. Dexter stands at the boundary between the lowlands of the Mississippi and the uplands of southern Missouri. The single insect from my Poplar Bluff collection has an interesting combination of unica, rydbergiana, and compta characters. Weld’s records (1926) for unica in southern Arkansas and in Texas, based on galls only, probably apply to anceps, and his Florida record to variety mellea. I cannot interpret his Virginia record (Pergande collection), but I question the occurrence of unica that far east.

Atrusca unica (Weld 1926)

Hosts: Quercus chapmanii

[Asexual generation detachable leaf gall found in the fall]