Xanthoteras teres, new species

Host.--Quercus garryana

Gall (fig. 40). —A globular knob on a cylindrical stalk hanging from a vein on underside of leaf in autumn, dropping with the leaf, single or but few on a leaf, covered with a dense short woolly white pubescence which weathers away in old galls. They measure up to 5.5 mm. long by 2.5 mm. in diameter. Monothalamous. The pubescence consists of a dense layer of short brownish hairs like an inner fur at the base of the long white hairs. Underneath is a thick brownish stony-hard layer and within a thin layer of light-colored tissue in which is the larval cavity.

Habitat. — The type material was collected in Sequoia National Park on September 8, 1922, on the scrubby Kaweah oak above the Cedar Creek checking station on the Giant Forest road. Living flies were cut out of the galls on November 13. The galls were also collected at Fort Jones and Scott Bar, Calif., and at Siskiyou, McLeod, Wolf Creek, Oakland, Cottage Grove, and Salem, Ore. Fresh galls reach their full growth in late July.

Xanthoteras teres Weld.

Quercus garryana
Leaf galls, detachable
Fig 159. Stalked pubescent ball, under side. Sept.

Fig 159. Q-garryana. A globular knob on a cylindrical stalk hanging from a vein on under side of leaf in autumn, dropping with the leaf. Up to 5.5 mm. long. Full-grown in late July. Adults were cut out in mid-November (Sequoia National Park), on Dec. 21 (Willite).

Xanthoteras teres
*Trigonapsis teres

This cynipid wasp induces monothalamous, stalked galls on the underside, near the margins of the leaves of Oregon and leather oak.

Hosts:
Quercus garryana
Quercus durata

Cynips teres
agamic forms

GALL. — Small, slender, stalked, swollen at the apex, resembling an inverted Indian club in shape. Up to 8.0 mm. in length and 2.7 mm. in width (near the apex). The stalk slender, strictly cylindrical except for a slight flare at the base, straight or bent, averaging 0.7 mm. in diameter, expanding gradually or abruptly into the swollen, spindle- shaped, or more spheroid body of the gall; the surface of the entire gall minutely granular, covered with a short, crystalline pubescence which more or less disappears with age; the young galls light, creamy brown, becoming light reddish brown and finally dark brown. Internally rather hard, crystalline, the outer wall solid, rather thin, the stalk filled with a less solid crystalline mass, the body of the gall occupied mostly by the larval cell which has a distinct cell wall but is imbedded closely against the outer wall of the gall. Attached more or less at right angles; occurring singly, or a few scattered over the leaf, on the under surfaces of the leaves of Quercus lobata, Q. garryana, Q. dumosa, and Q. durata.

RANGE. — Probably from British Columbia to California, now known from western Oregon and more northern California southward in the mountains and the foothills to the southern end of the San Joaquin Valley. Figures 28, 29.

Cynips teres var hidebrandae, new variety
agamic form

Gall. Rather short, up to 6.5 mm. in length, the stalk rather slender but not long, the swollen portion spherical, rounded at the apex; on leaves of Quercus dumosa and Q. durata. Figure 196.

Cynips teres var teres
agamic form

Gall. Shorter, more robust, up to 6. mm. in length, the stalk hardly longer than the swollen portion of the gall, the swollen portion quite spherical, well rounded at the apex; on leaves of Quercus garryana and its varieties.

RANGE. — Oregon: Salem, Cottage Grove, Oakland, Wolf Creek, McLeod, and Siskiyou (galls, acc. Weld 1926). California: Scott Bar and Fort Jones (galls, acc. Weld 1926). Yreka (galls, Kinsey coll.). Pit River, and Cow Creek near Millville (galls, Leach in Kinsey coll.). At about 4000 ft. in Sequoia National Forest (above Cedar Creek Checking Station; types, Weld coll.). Probably confined to higher elevations in Central California, and to more northern California and adjacent Oregon, wherever Q. garryana and its varieties occur. The Oregon records north of the Rogue River may represent a distinct variety. Figure 28.