Stenocranus harimensis Matsumura, 1935

Fujinuma, Satoshi & Hayashi, Masami, 2025, Taxonomic revision of Japanese Stenocranus (Hemiptera: Fulgoromorpha: Delphacidae), Zootaxa 5706 (3), pp. 301-336 : 318-320

Stenocranus harimensis Matsumura, 1935

[Japanese name: Harima-naga-unka (Hoso-naga-unka)]

( Figs 1 , 4 , 9 , 10 , 12 , 15 )

Stenocranus harimensis Matsumura, 1935: 129 [ Type locality: Japan ( Honshu : Tansanji ( Taisanji ), near Akashi in the Prov. Harima; Chichibu, Abiko)].

Stenocranus elongatus Matsumura, 1935: 127 [ Type locality: Japan ( Honshu !: Buzen ( Jono)]. syn. nov.

Lectotype designation. Four male syntypes (abdomen lost in two) are preserved in the Matsumura collection, with a red label on the same pin; thus, one male is designated as the lectotype. Some other specimens labeled as S. harimensis from the same locality are identified as S. takasagonis Matsumura.

Type material examined. Lectotype ♂ (here designated; SEHU), “28/VI Japan [ Taisanji (in Japanese)] Dr Matsumura // (red label) harimensis n.” . Paralectotypes: 3♂ ( SEHU), same data as lectotype . Holotype ♀ of S. elongatus (SEHU) , “ Japan Yano [Buzen (in Japanese)] Matsumura // elongatus M. det. Dr. Matsumura // (red label) elongatus Type” .

Other material examined. [Honshu] 5♂ 5♀ ( SF), Kamitakamori, Tsukidate, Kurihara , Miyagi Pref., 29. X. 2022, S. Fujinuma ; 5♂ 5♀ ( SF), Watarase Marsh, Fujioka , Tochigi, Tochigi Pref., 4. V. 2011, S. Fujinuma ; 2♂ 3♀ ( MH), Hozoji swamp, Mitakaya, Hanyu , Saitama Pref., 15. X. 2012, M. Hayashi et al .; 3♂ ( SF), same data except 25. IX. 2016, S. Fujinuma ; 11♂ 4♀ ( MH), Kurohama, Hasuda , Saitama Pref., 6. VIII. 1999 ( light trap), S. Ishida ; 8♂ ( MH), Heirinji, Iwatsuki , Saitama Pref., 8. VIII. 1999, S. Ishida ; 1♂ ( MH), Murakuni, Iwatsuki , Saitama Pref., 15. VII. 1999 ( light trap), S. Ishida ; 1♂ 2♀ ( MH), Akigase, Urawa , Saitama Pref., 31. I. 1987, M. Hayashi et al .; 3♂ ( MH), same data except 20. VI. 1990 ( light trap) ; 8♂ 15♀ ( SF), Kitaokawara, Minamiyamashiro , Kyoto Pref., 19. VI. 2015, S. Fujinuma; [ Tsushima Is.] 1♂ 1♀ ( MH), Meboro, Kami-agata , 27. X. 2002, M. Hayashi et al .; 1♂ ( MH), Mt. Ôboshi, Mine , 26. X. 2002, M. Hayashi et al .; 3♀ ( MH), Sumo, Mitsushima , 26. V. 1999, M. Hayashi et al.; [ Minami-Daito Is.] 2♀ ( MH), Ikenosawa , 18. IV. 1998, M. Hayashi .

Redescription. General coloration brown, strongly darker in summer form. Frons and genae mostly darker, carinae paler. Mid-dorsal parts of vertex, pronotum, and mesonotum widely whitish, fringed with orange and dark stripes (orange stripes usually lacking in summer form). Forewings translucent, brownish; veins darker particularly in membrane; dark markings on apices of apical veins; dark stripes along MP 3+4, the stripes broadly expanded in summer form. Male pygofer pale to dark brown.

Vertex about 1.5× as long as wide. Frons about 2.6× as long as wide, with median carina forked in apical 1/3 (rarely with two median carinae). Antennal segment II about 2.4× as long as wide. Forewing venation and hind leg spinulation as in S. niisimai . Post-tibial spur with 13–16 fine teeth.

Body length (mean): ♂ 4.7–5.8 mm ( 5.4 mm); ♀ 5.6–6.5 mm (6.0 mm).

Male genitalia: Similar to S. sapporensis except pygofer blunter at lateral sides of opening for gonostyles; apical process of phallotheca with short process on its base and minute process on subapex. Female genitalia is also similar to S. sapporensis except gonapophyses IX with 18–21 teeth; gonoplacs much rounded and wider in apical half.

Distribution. Japan ( Hokkaido, Honshu, Shikoku, Kyushu, Tsushima Is., Minami-Daito Is.).

Remarks. This species is similar to S. sapporensis in having the dark body and frons rarely with two median carinae, but it can be distinguished by the absence of curved stripes on the forewings and by the presence of a minute subapical process on the phallotheca. Examination of the holotype of Stenocranus elongatus Matsumura from Japan revealed that its habitus and female genital structures are identical to those of S. harimensis . Although S. elongatus has page precedence over S. harimensis , it was described based on a single female specimen, whereas S. harimensis was described based on male and female specimens. Therefore, it is preferable that S. elongatus becomes a junior synonym of S. harimensis for stability and universality of nomenclature (ICZN 4th edition: Recommendation 24A). In the original description of S. elongatus , the distribution is erroneously noted as Honshu; the type locality is actually “Jono in the Prov. Buzen,” northern Kyushu, western Japan.

Biological notes. This species inhabits mountainous to lowland marshes and feeds on Cyperus serotinus Rottb. ( Kisimoto 1995), Schoenoplectus triqueter (L.), and Carex dispalata Boott ( Cyperaceae ). Females lay eggs exclusively in the middle to upper parts of scapes of C. dispalata in spring but shift oviposition sites to the lower parts of leaves in summer, as observed in some congeners feeding on the same host.

Figures

FIGURE 1. Habitus and faces of Stenocranus (all males except G). A, D, H, J, winter form; B, C, E, I, summer form.—A–C, K, S. niisimai; D, E, L, S. tamagawanus; F, G, M, S. sapporensis; H, I, N, S. harimensis; J, O, S. tateyamanus. Scales: 1.0 mm.

FIGURE 4. Habitus and labels of type material of Stenocranus (all males except A, C, I, Q). N, under side of locality label is surrounded by dotted line.—A, B, S. niisimai (holotype); C, D, S. breviceps Matsumura (lectotype); E, F, S. tamagawanus (lectotype); G, H, S. vittatus Matsumura (lectotype); I, J, S. koreanus (holotype); K, L, S. sapporensis (lectotype); M, N, S. ozenumensis (paratype); O, P, S. harimensis (lectotype); Q, R, S. elongatus (holotype).

FIGURE 9. Male genitalia of Stenocranus and Ceratocranus gen. nov. in lateral view.—A, S. niisimai; B, S. tamagawanus; C, S. sapporensis; D, S. harimensis; E, S. tateyamanus; F, S. kisimotoi sp. nov.; G, S. takasagonis; H, S. fallax; I, S. chenzhouensis; J, S. tonghuaensis; K, C. agamopsyche; L, C. aurantius sp. nov. Scales: 0.2 mm.

FIGURE 10. Male genitalia of Stenocranus and Ceratocranus gen. nov. in ventrocaudal view.—A, S. niisimai; B, S. tamagawanus; C, S. sapporensis; D, S. harimensis; E, S. tateyamanus; F, S. kisimotoi sp. nov.; G, S. takasagonis; H, S. fallax; I, S. chenzhouensis; J, S. tonghuaensis; K, C. agamopsyche; L, C. aurantius sp. nov. Scales: 0.2 mm.

FIGURE 12. Male genitalia (A–J) and female genitalia (K–M) of Stenocranus. A–C, phallotheca in lateral view; D–F, same in ventral view; G, suspensorium in anterior view; H–J, gonostyle in widest view; K–M, gonoplac in ventral view.—A, D, H, K, S. harimensis; B, E, I, L, S. tateyamanus; C, F, G, J, M, S. kisimotoi sp. nov.

FIGURE 15. Oviposition holes and eggs of Stenocranus on plants.A, D, G, L, N, oviposition holes covered with wax; B, E, H, O, the holes removed wax; C, F, I, K, M, P, eggs in the holes.—A–C, S. niisimai on Phalaris arundinacea; D–F, S. tamagawanus on P. arundinacea; G–I, S. sapporensis on Scirpus wichurae; J, K, S. harimensis on Carex dispalata; L, M, S. tateyamanus on Carex scabrifolia; N–P, S. takasagonis on Schoenoplectiella juncoides.