[In Druon quercusflocci: comments]

A sample of galls on leaves collected from Aguascalientes State (Mexico) on Quercus potosina produced two adults morphologically resembling D. quercusflocci. The galls have a completely whitish woolly covering over clusters of 2–6 seed-like distinct larval chambers attached to the midrib of leaves (Fig. 150, right). The galls of D. quercusflocci from USA are densely pubescent, mainly orange-brown with some scattered white wool (Fig. 150, left). The internal structure of distinctly separated larval chambers is shared by both of these gall morphologies. The adults from Mexico differ slightly from typical D. quercusflocci by the following mesopleural and mesoscutellar characters. [...] We consider these differences insufficient to define two separate species, but the phenotypic differences in gall traits may indicate that the Mexican specimens belong to a different species. Alternatively, the differences may result from host plant effects on gall structure, as seen in some other oak cynipid galls with a wide host range (e.g. asexual generation leaf galls of Cynips quercusfolii Linnaeus, 1758 in the Western Palaearctic, which are smooth when developing on Quercus robur L. but covered with raised tubercles when developing on Q. petraea (Matt.) Liebl.). Thus, we have not officially assigned the Mexican specimens to D. quercusflocci and await more material and further evidence, such as molecular data

- 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^©