Stenocranus tateyamanus Matsumura, 1935

Fujinuma, Satoshi & Hayashi, Masami, 2025, Taxonomic revision of Japanese Stenocranus (Hemiptera: Fulgoromorpha: Delphacidae), Zootaxa 5706 (3), pp. 301-336 : 320-322

Stenocranus tateyamanus Matsumura, 1935

[Japanese name: Tateyama-naga-unka (Sukumo-naga-unka)]

( Figs 1 , 2 , 5 , 8–10 , 12 , 15 )

Stenocranus tateyamanus Matsumura, 1935: 131 [ Type locality: Japan ( Honshu : Tateyama)].

Stenocranus sukumonus Matsumura, 1935: 71 [ Type locality: Japan (Shikoku: Sukumo, Pref. Kochi (Tosa))]. syn. nov. Stenocranus akashiensis : Ishihara, 1949: 27 (nec Matsumura , 1935).

Lectotype designation. In the syntypes of Stenocranus tateyamanus Matsumura , three males and one female (despite two pairs stated in the original description) are preserved with a red label on the same pin; thus, one of the males is designated as the lectotype. In the syntypes of Stenocranus sukumonus Matsumura , two males are preserved with a red label on the same pin; one of the males is designated as the lectotype. The collection date of S. sukumonus is noted as August 8, 1916 in the original description, but the syntype labels record July 28, 1916, suggesting a possible error in the date of the original description.

Type material examined. Lectotype ♂ of S. tateyamanus (here designated; SEHU), “ 11/VIII 1905 // Tateyama Japan Matsum (u)ra // Stenocranus tateyamanus sp. nov. // (red label) ( T)ype” . Paralectotypes: 2♂ 1♀ ( SEHU), same data as lectotype . Lectotype ♂ of S. sukumonus (here designated; SEHU), “ Japan Matsumura , (under side) [ Sukumo (in Japanese)] 1916 28/VII // (red label) Stenocranus sukumonus n. Type ” . Paralectotypes: 1♂ ( SEHU), same data as lectotype ; 1♂ ( SEHU), “ Japan Matsumura , (under side) [ Sukumo (in Japanese)] 1916 28/VII // Stenocranus sukumonis (!) Matsum.” .

Other material examined. [Honshu] 2♂ 2♀ ( SF), Nobiru Beach, Higashi-matsushima , Miyagi Pref., 9. IV. 2022 , S. Fujinuma; 2♂ 1♀ ( MH), Arai Beach, Arai, Kashima , Ibaraki Pref., 2. VIII. 1997 , R. Kisimoto; 5♂ 5♀ ( SF), Kujukuri Beach, Sorigane, Shirako , Chiba Pref., 14. IX. 2014 , S. Fujinuma; 2♂ 3♀ ( MH), Kaino, Kihoku , Mie Pref., 3. XI. 1993 . R. Kisimoto; [ Shikoku ] 1♂ 3♀ ( MH), Komatsu Beach, Tokushima, Tokushima Pref., 22. X. 2006 . M. Hayashi et al.; 3♂ 3♀ ( MH), Kitaokinosu, Tokushima, Tokushima Pref., 27. X. 2004 . M. Hayashi et al.; [ Tsushima Is. ] 19♂ 18♀ ( MH), Miuda, Kami-tsushima , 27. X. 2001 , M. Hayashi et al.; 3♂ 3♀ ( MH), same data except 28. X. 2002 ; 1♀ ( MH), Tanohama, Kami-agata , 27. X. 2001 , M. Hayashi et al.

Redescription. General coloration stramineous, strongly paler in summer form. Frons with broad dark stripes, with distinct pale spots on the stripes. Genae with dark stripes. Mid-dorsal parts of vertex, pronotum, and mesonotum widely whitish, fringed with orange and dark stripes (stripes usually feeble in summer form). Forewings as in S. harimensis except veins paler in summer form. Male pygofer pale to dark brown.

Vertex about 1.4× as long as wide. Frons about 2.6× as long as wide, with median carina forked in apical 1/3. Antennal segment II about 2.4× as long as wide. Forewing venation and hind leg spinulation as in S. niisimai . Post-tibial spur with 13–15 fine teeth.

Body length (mean): ♂ 4.5–5.0 mm ( 4.7 mm); ♀ 5.2–5.8 mm ( 5.5 mm).

Male genitalia: Pygofer, suspensorium and anal tube as in S. sapporensis except caudal margin of pygofer strongly rounded. Gonostyles relatively broad in basal half in widest view, apically narrowed, then slightly curved dorsad; basal angles short. Phallotheca broad in lateral view, strongly produced ventrad in subapical part; opening on left side, with small process originating from membranous part of the opening; apical process long and falcate, produced dorsad, then downcurved. Female genitalia: Gonapophyses VIII slender in ventral view, weakly serrated on lateroapical parts. Gonapophyses IX with 13–18 teeth, symmetrically diverged basally. Gonoplacs semicircular in ventral view, broad, wider in apical half.

Distribution. Japan (Honshu, Shikoku, Kyushu, Tsushima Is.).

Remarks. This species can be distinguished by the following features: frontal dark stripes wide with contrasting pale spots; phallotheca widened apically with a large process; phallothecal opening with a small process. The small process probably exhibits geographic variations, as it tends to be longer in eastern Honshu than in more western regions of Japan. Examination of the syntypes of Stenocranus sukumonus Matsumura from Japan shows that these features of S. sukumonus are identical to those of the summer form of this species; therefore, S. sukumonus should be regarded as a junior synonym of this species.

Additionally, investigation of the Matsumura collection revealed that some specimens labeled as Stenocranus akashiensis Matsumura include both S. tateyamanus and Sogata hakonensis (Matsumura) . Moreover, the features in the original description of S. akashiensis (absence of dark leg stripes, gonostyles diverging to apices) are not identical to Stenocranus species but to Sogata hakonensis (Matsumura) , and thus S. akashiensis was treated as a junior synonym of S. hakonensis ( Fujinuma 2016) . Owing to this confusion, S. akashiensis may have been erroneously treated and illustrated as S. tateyamanus in some publications (e.g., Matsumura & Ishihara 1945, Ishihara 1949).

Biological notes. This species strictly inhabits seaside wetlands and feeds on Carex scabrifolia Steud. ( Cyperaceae ) ( Kisimoto 1995). Females lay eggs in basal parts of leaves or sheathes of the host plant. Moreover, numerous adults are sometimes collected from Carex pumila Thunb. growing on sand dune environment.

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 2. Habitus and faces of Stenocranus (all males except H). B, D, F, H, I, winter form; A, C, E, G, J, summer form.—A, S. tateyamanus; B, C, K, S. kisimotoi sp. nov.; D, E, L, S. takasagonis; F–H, M, S. fallax; I, J, N, S. chenzhouensis. Scales: 1.0 mm.

FIGURE 5. Habitus and labels of type material of Stenocranus (all males except G, K, M, Q). D, J, under side of locality label is surrounded by dotted line.—A, B, S. tateyamanus (lectotype); C, D, S. sukumonus (lectotype); E, F, S. takasagonis (lectotype); G, H, S. fallax (lectotype); I, J, S. formosanus (lectotype); K, L, S. akashiensis (lectotype); M, N, S. ogasawarensis (lectotype); O, S. hopponis (syntype); P, S. silvicola (holotype); Q, S. agamopsyche (holotype); R, S. pacificus (holotype).

FIGURE 8. Female genitalia of Stenocranus, Ceratocranus gen. nov. and Terauchiana. A–H, gonapophysis IX in dorsal view; I–P, same in lateral view.—A, I, S. niisimai; B, J, S. tamagawanus; C, K, S. sapporensis; D, L, S. tateyamanus; E, M, S. kisimotoi sp. nov.; F, N, S. chenzhouensis; G, O, C. aurantius sp. nov.; H, P, T. singularis.

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.