Fagineura quercivora Hara & Ibuki 2022, comb. nov.
Creators: name: Hara, Hideho
name: Ibuki, Shinichi
Publisher: name: Zenodo
Year: 2022
Subjects: Biodiversity
Taxonomy
Animalia
Arthropoda
Insecta
Hymenoptera
Tenthredinidae
Fagineura
Fagineura quercivora

description: Fagineura quercivora (Togashi, 1997), comb. nov.
(Figs 4I–K, 5A–C, I, J, 6J, K, S, 7H, N, 8C, D, L, M, T, U, 9F, G, N, O, 10H, I, 13A–C)
Dineura quercivora Togashi, 1997: 196; Wei 2002: 86; Taeger et al. 2010: 400; Hara 2019: 71; Hara 2020: 80, 326.
Additional description: female (holotype). Length 7.0–9.0 mm (holotype 8.0 mm). Reddish brown with black markings (Figs 4I–K, 5A–C). Postocellar area partly or entirely black (Figs 6J, K). Postspiracular sclerite red yellow or black (Figs 8L, M). Mesepimeron black on anepimeron, yellow red on katepimeron. Abdomen black on medial parts of four to six basal terga (Figs 4J, 5A).
Head in dorsal view with length behind eye 0.4–0.8 × eye length (Fig. 6J, K); length behind lateral ocellus 2.5–3.4 × length of lateral ocellus. OOL:POL:OOCL 0.8–1.0:1.0:1.0–1.4. Frontal area with weak lateral ridge and well developed anterior ridge (Fig. 6S); frontal field with long lateral convexity. Distance between eyes at anterior tentorial pit 1.2–1.4 × major axis of eye (Fig. 4I). Inner edges of eyes nearly parallel. Malar space 0.3–0.7 × as long as median ocellus width. Antenna 2.0–2.5 × as long as head width (Figs 4J, 5A); flagellum slightly tapered; flagellomere 1 0.7–0.8 × as long as major axis of eye; flagellomere 2 1.0–1.2 × as long as flagellomere 1. Mesepisternum distinctly expanded beside postspiracular sclerite (Figs 8L, M). Hind tibia with posterior spur 0.8–1.1 × as long as apical breadth of tibia. Forewing usually without crossvein 2r-rs (Fig. 5A) (the holotype has a normal crossvein 2r-rs in both fore wings, Fig. 4J; one female has an abnormal crossvein 2r-rs in both fore wings, that is vague and located very close to the base of cell R1).
Valvula 3 in dorsal view about twice as wide as cercus, not concave apically (Figs 9F, G), in lateral view with narrowly rounded or pointed apically, with dorsal edge slightly rounded or straight and ventral edge rounded, sometimes straight near apex (Figs 9N, O). Lance with dorsal edge slightly rounded (Figs 10H, I). Lancet with radix about 0.4–0.5 × as long as lamnium (Figs 13A–C); lamnium with 20–22 annuli; basal annuli slightly sinuous; middle and apical annuli straight and oblique; ctenidia widely separated from each other; basal two annuli with ctenidia very small and consisting of one row of setae; other ctenidia except for some apical ctenidia each slightly expanded dorsally and consisting of some irregular transverse rows of setae; basal serrulae with anterior slope shorter than posterior slope.
Head and thorax with punctures minute; interspaces between punctures generally smooth. Lateral lobe of mesoscutum anteriorly sparsely punctured and with wide smooth area (Fig. 8C) or uniformly moderately punctured all over (Fig. 8D); posterolateral hollow with rugose and granular microsculpture. Mesopostnotum with rugose and granular microsculpture, medially smooth. Metapostnotum mostly smooth. Postspiracular sclerite with many setae. Mesepisternum widely glabrous beside postspiracular sclerite (Fig. 8L). Katepimeron with setae on narrow dorsal area and along posterior margin. Abdomen microsculptured imbricately, with punctures inconspicuous.
Male. Unknown.
Immature stages. Early instar larva: entirely black (Fig. 5I). Late and final instar larva: 18 mm long in final instar; head black (Fig. 5J); trunk mostly black; thoracic legs apically pale yellow; abdomen dorsally yellow or red yellow on anterior and middle segments. Cocoon: 10–11 mm long, blackish brown, single walled.
Material examined. Holotype: ♀, “ Tokuho, Suzu-shi, Ishikawa Pref., 3. IV. 1989, I. Togashi ”, “ Holotype ”. “ Dineura quercivora sp. nov. ” “NEM-11”, “ NSMT-HYM 62139 ” (Figs 4I–K, 6J, S, 7H, N, 8C, L, T, 9F, N, 10H, 13A).
Other material examined: JAPAN: HONSHU: 1♀, Tochigi Pref., Nakagawa, Wami, coll. larva on Quercus serrata 19. V. 2011, mat. 21. V., em. 12. IV. 2012, S. Ibuki (Figs 5A–C, 13B); 2♀, same data but 36°46’N 140°10’E, coll. larvae 14. V. 2012, mat. 16–17. V., em. 29. III. 2013 (Fig. 5L); 4♀, same data but coll. larvae 4. V. 2018, mat. 11. V., em. 20. IV. 2019 (Fig. 9O); 3♀, same data but coll. larva 5. V. 2018, mat. 12. V., em. 18. IV. 2019 (Figs 5D, E, 6K, 8D, M, U, 9G, 10I); 1♀, Hyogo Pref., Kami, Muraoka, Kojo, 21. IV. 1991, T. Yagi; 1♀, Hyogo Pref., Tamba-Sasayama, Quercus serrata, reared, 20. IV. 1955, T. Okutani; 1♀, same data, larva black. ― LOCALITY UNKNOWN (probably Japan): 1♀, “ Akadani (in Japanese)”, 3. V. 1952, Y. O.; 1♀, “narakurohabachi (in Japanese)” ― KOREA: 1♀, Jeollanam-do, Mt. Nogodan, 1200 m, 26–28. V. 1997, A. Shinohara (Fig. 13C).
Distribution. Japan (Honshu) (Togashi, 1997), Korea (new record).
Life history. Host plants: Fagaceae: Quercus dentata Thunb. (Togashi, 1997), Q. serrata Murray (new record).
This species has one generation per year. In Honshu, Japan, adults appear on late April and early May and larvae on early and middle May. Eggs are laid in a young shoot (Fig. 5I). Larvae are gregarious. Mature larvae enter the soil and make cocoons.
Remarks. Fagineura quercivora was described under Dineura Dahlbom, 1835. According to Prous et al. (2014), Dineura has the mandibles both regularly tapered, the malar space 1.0–2.0 times as long as the median ocellus diameter and the anterior fore tibial spur without a velum, but F. quercivora as well as other members of the F. quercivora group have the mandibles both markedly constricted in the middle, the malar space shorter than a median ocellus width and the anterior fore tibial spur with a velum. The lancet of F. quercivora is very similar to those of other species of the F. quercivora group, but it is quite different from those of Dineura species (compare with Fig. 13A with figs 23–27 in Liston et al. 2019).
The holotype of F. quercivora has a normal crossvein 2r-rs in both fore wings (Fig. 4J), whereas other specimens have not crossvein 2r-rs except for one female with an abnormal crossvein 2r-rs in both fore wings. Furthermore, the holotype somewhat differs from other specimens in having the postspiracular sclerite entirely pale (widely or entirely black in other specimens), the slightly smaller eye so that the head length behind the eye, the distance between the eyes and the length of the malar space are slightly longer than those of other specimens, and the lateral mesoscutal lobe anteriorly very sparsely punctured (Fig. 8C) (more densely punctured in other specimens; Fig. 8D). However, we conclude that the holotype and the other specimens are conspecific, because large intraspecific variability of venation is often seen in the Nematinae (see Liston et al. 2017, 2019) and the other differences are slight.
This species is similar to F. glabella in color, but differs from it as stated in the key. For more differences, see the remarks of the latter species.
description: Published as part of Hara, Hideho & Ibuki, Shinichi, 2022, A study of the genus Fagineura (Hymenoptera, Tenthredinidae, Nematinae), pp. 223-252 in Zootaxa 5116 (2) on pages 240-245, DOI: 10.11646/zootaxa.5116.2.3, http://zenodo.org/record/6367255