Druon ignotum (Bassett, 1881), comb. nov.

Cynips ignota Bassett, 1881: 106, female, gall.
Andricus ignota (Bassett): Ashmead, 1885: 295.
Dryophanta ignota (Bassett): Ashmead, 1887: 127.
Diplolepis ignota (Bassett): Dalla Torre & Kieffer, 1910: 360. [NOT Diplolepis ignota Osten Sacken, 1863]
Rhodites ignota (Bassett): Dalla Torre, 1893: 127. [NOT Andricus ignota Bassett, 1900 (junior homonym).]
Diplolepis ignota (Bassett): Weld, 1926: 26.
Andricus ignotus (Bassett): Weld, 1951: 634.

Gall. Asexual galls (Fig. 99). Small (2–3 mm long) brown, thin-walled and gregarious ovoid galls firmly attached to the underside of the leaf midrib in clusters of up to 30 or more. The entire cluster is covered with a dense coating of long woolly hairs, which is initially cream-coloured or pink but fades to brown over the winter, and sometimes wears away.

Biology. Alternate asexual and sexual generations are known (see comments). See Bassett (1881) and Weld (1926) for the biology of the asexual generation. Asexual galls have been recorded on leaves of Q. bicolor and Q. macrocarpa (Section Quercus, Series Prinoideae), mature in October–November, adult females emerge very early the following spring (late March to late April in Edmonton, Alberta, Canada), often on the first warm days after accumulated snow has melted and fallen leaves bearing galls are exposed. Emerged females fly up to buds and oviposit. The sexual generation adults emerged in Edmonton in early June. Females were observed ovipositing multiply along the midrib on the upper leaf surface in a zipper-like pattern, suggesting that asexual females in a given gall cluster are sisters. Galls of the asexual generation first became apparent on leaves in Edmonton in late July.

Distribution. USA: Massachusetts, Connecticut, Illinois, Minnesota (Burks 1979), Nebraska (Weld 1926); Canada: Alberta, Manitoba.

- Victor Cuesta-Porta, George Melika, James Nicholls, Graham Stone, Juli Pujade-Villar: (2022) Re-establishment of the Nearctic oak cynipid gall wasp genus Druon Kinsey, 1937 (Hymenoptera: Cynipidae: Cynipini), with description of five new species^©