Fagineura quercivora (Togashi, 1997) Hara & Ibuki, 2022

Hara, Hideho & Ibuki, Shinichi, 2022, A study of the genus Fagineura (Hymenoptera, Tenthredinidae, Nematinae), Zootaxa 5116 (2), pp. 223-252 : 233-234

Fagineura quercivora group

Diagnostic characters. Major axis of eye in lateral view 4–5 × distance from eye to dorsalmost point of head ( Fig. 6N ). Frontal pit dorsally without median groove ( Figs 6R, S ). Clypeus with width 2.7–3.6 × maximum height; maximum height 1.0–1.3 × torulus height ( Fig. 7C ); ventral emargination deep and wide; depth of emargination 0.6–1.1 × median height of clypeus. Mandibles slightly asymmetric; in outer view, left mandible sharply tapered basally, very gradually tapered or being same thickness from middle to near apex ( Figs 7F–I ), with sharp apical carina on anterior surface and low and dull apical carina on posterior surface ( Figs 7R, S ); right mandible sharply tapered basally, being same thickness or slightly thickened toward apex in middle part ( Figs 7L–O ), with low and dull apical carina on anterior surface and sharp apical carina on posterior surface ( Figs 7R, S ).

Ventral edge of epicnemium narrowly grooved, sometimes not grooved. Katepimeron widely covered with setae. In fore wing, vein C apically distinctly or moderately dilated, and cell Sc 0.1–0.5 × as wide as vein C at middle point of origin of vein Rs+M ( Fig. 8Y ); crossvein 2r-rs absent ( Figs 2H, L , 4B, G , 5A, F ) or present ( Fig. 4J ).

In female, cercus about 8–9 × as long as wide ( Figs 9C–H, K–P ). Valvula 3 apically very slightly emarginate or not in dorsal view ( Figs 9C–H ). In lance, radix with subdorsal carina ( Figs 10D–J ). In lancet, tangium without pores ( Figs 12A–E , 13A–E ); sclerotized part before lamnium large, extending anteriorly along olistheter; annulus 1 anteriorly with vestigial ctenidium or without ctenidium and without distinct colorless area. In male abdomen, penis valve with valvispina directed posterodorsally, thorn like ( Figs 14O, P ).

Remarks. The F. quercivora group is distinguished from the F. crenativora group and the related genera by the right mandible markedly constricted in the middle and with a sharp apical carina on the posterior surface ( Figs 7L–O, S ). This character appears to be apomorphic to the Nematinae and may support the monophyly of the F. quercivora group. For more discussion, see the remarks of the genus.

Fagineura flavomaculata , F. glabella and F. quercivora are characterized by the dorsally distinctly expanded and glabrous mesepisternum ( Figs 8K–N ). Fagineura fulvistriata has a similar mesepisternum, though the expansion is slight and the glabrous area is very narrow ( Fig. 8J ). The dorsally expanded and glabrous mesepisternum is considered apomorphic to the Nematinae and suggests a close relationship between these four species.

Figures

FIGURE 2. Fagineura parva (A–C, female, holotype; D–F, male) and F. togashii (G–J, female; K–N, male). A, D, G, K, Head, frontal view; B, E, H, L, dorsal view; C, F, I, M, ventrolateral or lateral view; J, N, ventral view. G–N, Photographed just after killing.

FIGURE 4. Fagineura fulvistriata (A–E, female; L, M, late instar and mature final instar larva; holotype), F. flavomaculata (F–H, N, female; O–Q, late instar, final instar and mature final instar larva; holotype) and F. quercivora (I–K, female, holotype). A, F, I, Head, frontal view; B, E, G, J, dorsal view; C, H, K, lateral or ventrolateral view; D, ventral view. L–Q, Nakagawa; L, 13 May 2019; M, 20 May 2019; N, 19 April 2019; O, 2 May 2018; P, 8 May 2018; Q, 9 May 2018; photographed by S. Ibuki. A–D, Photographed just after killing.

FIGURE 5. Fagineura quercivora (A–C, female; I, early instar larvae; J, final instar larvae) and F. glabella (D–H, female, holotype). A, D, H, Dorsal view; B, E, lateral view; C, F, ventral view; G, head, frontal view. I, Nakagawa, 5 May 2016; J, Nakagwa, 14 May 2012. A–F, Photographed by F. Ito, just after killing; I, J, photographed by S. Ibuki.

FIGURE 6. Head: Fagineura crenativora (A, B, M, O, P, female; A, M, holotype; C, male), F. parva (D, Q, female, holotype; E, male), F. togashii (F, N, R, female; G, male), F. fulvistriata (H, female, holotype), F. flavomaculata (I, female, holotype), F. quercivora (J, K, S, female; J, S, holotype) and F. glabella (L, female, holotype). A–L, Dorsal view; M, N, lateral view; O, anteromedial part, anterolateral view; P–S, anterodorsal view.

FIGURE 7. Mandible: Fagineura crenativora (A, B, D, J, P, Q, female; A, holotype), F. parva (E, K, female, holotype), F. togashii (C, F, L, R, S, female), F. flavomaculata (G, M, female, holotype), F. quercivora (H, N, female, holotype) and F. glabella (I, O, female, holotype). A, Ventral view; B, C, anterior view (C, max. h. = maximum height); D–I, left mandible, outer view, left anterior; J–O, right mandible, outer view, left posterior; P, R, anterior view; Q, S, posterior view.

FIGURE 8. Thorax, claw and anteromiddle part of fore wing: Fagineura crenativora (A, G, O, W, X, female; O, W, holotype), F. parva (H, male; P, female, holotype), F. togashii (F, I, Q, female), F. fulvistriata (J, R, Y, female; J, R, holotype), F. flavomaculata (B, K, S, female, holotype), F. quercivora (C, D, L, M, T, U, female; C, L, T, holotype) and F. glabella (E, N, V, female, holotype).A–E, Mesoscutum, dorsolateral view; F, anterodorsal part of mesepisternum, anteroventral view; G–N, dorsal part of mesepisternum, anterolateral view; O–V, claw, anterior or posterior view; W–Y, anteromiddle part of fore wing.

FIGURE 9. Apex of female abdomen: Fagineura crenativora (A, I), F. parva (B, J, holotype), F. togashii (C, K), F. fulvistriata (D, L; D, holotype), F. flavomaculata (E, M; E, holotype), F. quercivora (F, G, N, O; F, N, holotype) and F. glabella (H, P, holotype). A–H, Dorsal view; I–P, lateral view.

FIGURE 10. Ovipositor or lance, lateral view: Fagineura crenativora (A, B), F. parva (C, holotype), F. togashii (D, E), F. fulvistriata (F), F. flavomaculata (G, holotype), F. quercivora (H, I; H, holotype) and F. glabella (J, holotype).

FIGURE 12. Lancet: Fagineura togashii (A, B), F. fulvistriata (C, holotype) and F. flavomaculata (D, E; D, holotype). A, B, C, Reversed.

FIGURE 13. Lancet: Fagineura quercivora (A–C; A, holotype) and F. glabella (D, E; D, holotype). A, Reversed.

FIGURE 14. Apex of male abdomen and genitalia: Fagineura crenativora (A, D–F, K, L), F. parva (B, G, H, M, N) and F. togashii (C, I, J, O, P). A–C, Apex of abdomen, dorsal view; D, G, I, genitalia, dorsal view; E, F, H, J, genitalia, ventral view (E, H, J, penis valve removed); K–P, penis valve, left dorsal.