Druon quercusflocci (Walsh, 1864), comb. nov.

? Cynips Quercus-lana Fitch, 1859: 814, adult, galls (see comments)
Cynips quercus flocci Walsh, 1864: 482, female, gall.
Cynips (Andricus?) flocci Osten Sacken, 1865: 352.
Andricus flocci (Walsh): Mayr, 1881: 28.
Andricus quercusflocci (Walsh): Burks, 1979: 1087

Gall. (Fig. 150). Woolly, dirty white to pinkish pubescent galls, 10–12 mm long, 8.0–8.5 mm broad and 4–5
mm high, containing 2–10 seed-like larval chambers attached at one end to the midrib on the upper or lower side of the leaf; the cluster of galls is usually elongated along the direction of the leaf midrib. The larval cells are distinct individually, rather than fused into a single mass, 0.2–1.0 mm in diameter, and covered with short crystalline hairs.

Biology. Only an asexual generation is only known, which induces leaf galls on Q. alba (Section Quercus,
Series Albae) in autumn.

Distribution. USA: Massachusetts to North Carolina, Michigan, Illinois, Missouri, Arkansas (Burks 1979).

Comments. Fitch (1859) described a similar gall named Cynips Quercus-lana but the adults he reared are
cynipid inquilines belonging to Synergus according to keys in Cresson (1887) and Lobato-Vila & Pujade-Villar (2021). The galls are indistinguishable from other similar galls, and we cannot determine whether this gall corresponds to Andricus (now Druon) quercusflocci. Dalla Torre & Kieffer (1910: 544) nevertheless considered Andricus quercusflocci to be a possible junior synonym of Andricus quercuslana. The specific name ‘quercuslana’ corresponds to a Synergus species, leaving the gall described by Fitch (1859) as unidentifiable (?Cynips quercuslana Fitch, 1859).

Andricus flocci

Quercus alba, prinus [montana]
Leaf galls, detachable
Woolly, dirty white, of 2-10 seed-like bodies attached by one end on midrib on upper or lower side, dropping with the leaf, in fall.

[Photo caption]
On Q alba. Also on Q prinus [montana]. Galls fall with the leaves and remain on them over winter. Adults emerge the next spring Apr 22, 24, 30 and May 2, 5 (CT); April 14-16 (PA). Have been observed ovipositing in subapical buds Apr 15 (PA).

ANDRICUS FLOCCI (Walsh)

Galls were collected on Quercus alba at Evanston, Glencoe, Glen Ellyn, New Lenox, and Moline. IL.; Porter. Ind. ; Ironton and Poplar Bluff. Mo.; Texarkana, Ark.; Marianna, Fla. ; and Bluemont. Va. Crosby collected them at Riverhead and Zabriskie at Nyack. N. Y. Brodie had galls sent to him from Manitoba from which flies emerged at Toronto May 20.

From galls collected at Ironton in October. 1917, adults emerged May 16-28, 1918. The forest-insect collection has flies that emerged April 22, 24, 30. and May 2 and 5, 1915 from galls collected at Lyme. Conn., by A. B. Champlain and flies that emerged April 14— 16, 1915, from galls from Harrisburg, Pa. On April 15 William Mliddleton liberated some of the latter in a cage on a white oak tree and observed oviposition in one of the subapical buds. From the resulting gall he reared adults of both sexes on June 19 — a suggestion for further experimentation.