Fagineura crenativora group

Diagnostic characters. Major axis of eye in lateral view 2–4 × distance from eye to dorsalmost point of head (Figs 1C, 6M). Frontal pit dorsally with median groove (Figs 6P, Q). Clypeus with width 3.2–3.8 × maximum height (Fig. 7B); maximum height 0.8–1.0 × torulus height; ventral emargination distinct and wide; depth of emargination 0.3–0.6 × median height of clypeus. Mandibles symmetric (Figs 7A, B); in outer view, each rather sharply tapered basally, gradually tapered from middle to apex (Figs 7A, D, E, J, K), with low and dull apical carina on each of anterior and posterior surfaces (Figs 7P, Q).

Ventral edge of epicnemium narrowly and distinctly grooved. Katepimeron extensively or posteriorly covered with setae, sometimes with only a few or several setae. In fore wing, vein C apically slightly or distinctly dilated, and cell Sc 0.3–1.0 × as wide as vein C at middle point of origin of vein Rs+M (Figs 8W, X); crossvein 2r-rs absent (Figs 1B, F, J, M, 2B, E).

In female abdomen, cercus about 4–6 × as long as wide (Figs 9A, B, I, J). Valvula 3 apically emarginate or pointed in dorsal view (Figs 9A, B; fig. 2f in Liu et al. 2019). In lance, radix without subdorsal carina (Figs 10A–C). In lancet, tangium with or without pores (Figs 11A–C); sclerotized part before lamnium being narrow transverse band; annulus 1 anteriorly with transverse colorless area with ctenidium. In male abdomen, penis valve with valvispina directed posteroventrally (Figs 14K–N).

Remarks. The F. crenativora group is distinguished from the F. quercivora group as stated in the key above. In all members of the group, the lancet has the annulus 1 with a ctenidium in a distinct transverse colorless area and the sclerotized part before the annulus 1 being a narrow transverse band (Figs 11A–C; figs 2A–H in Liu et al. 2021). In the related genera such as Euura, Nematus and Pristiphora and the F. quercivora group, the annulus 1 usually does not have a ctenidium (see Benson 1958, Liston et al. 2017, Prous et al. 2017, 2019, 2021), and if it has a ctenidium, the area around the ctenidium is not widely colorless or the sclerotized part before the lamnium is absent or does not become a narrow transverse band (e.g. figs 22, 24 in Smith 2012; Fig. 13E). Therefore, this character of the F. crenativora group appears to be unique in the Nematinae and may support the monophyly of the group.