Stenocranus kisimotoi, Fujinuma & Hayashi, 2025

Fujinuma, Satoshi & Hayashi, Masami, 2025, Taxonomic revision of Japanese Stenocranus (Hemiptera: Fulgoromorpha: Delphacidae), Zootaxa 5706 (3), pp. 301-336 : 322-324

Stenocranus kisimotoi sp. nov.

[Japanese name: Kisimoto-naga-unka]

( Figs 2 , 3 , 7–10 , 12 )

Stenocranus ozenumensis : Kisimoto, 1995: 52 (nec Ishihara, 1952).

Holotype: ♂ ( ELKU), Okawara, Minamiyamashiro , Kyoto Pref., 6. XI. 1993. R. Kisimoto . Paratypes: [Honshu] 8♂ 7♀ ( ELKU), Sakura Pass, Marubashira, Ayama , Mie Pref., 9. XI. 1993, R. Kisimoto ; 2♂ 3♀ ( ELKU), same data as Holotype ; 8♂ 10♀ ( ELKU), Hiyoshi, Mizunami , Gifu Pref., 20. VI. 2015, S. Fujinuma ; 10♂ 10♀ ( ELKU), same data except 26. VII. 2015, S. Fujinuma.

Description. General coloration stramineous, darker in summer form. Vertex with anterolateral compartments darker. Frons with dark stripes except along basal half of median carina feeble. Genae slightly darker. Mid-dorsal parts of vertex, pronotum, and mesonotum narrowly whitish (wider in summer form), fringed with orange stripes. Forewings translucent, brownish (smoky in summer form); veins darker, particularly in membrane; dark markings on apices of apical veins; dark stripes on membrane (darker in summer form). Legs with dark stripes. Male pygofer darker.

Vertex about 1.7× as long as wide. Frons about 2.9× as long as wide; median carina not forked to slightly forked in apical 1/3. Antennal segment II about 2.7× as long as wide. Pronotum about 0.7× as long as vertex. Mesonotum about 2.0× as long as pronotum. Forewing venation: ScP, RA, and RP unbranched, MP 3-branched, CuA 3-branched. Hind leg spinulation: tibia 5 (2 + 3), basitarsus 7 (2 + 5), second tarsomere 4. Post-tibial spur with 21–24 fine teeth.

Body length (mean): ♂ 4.3–4.8 mm ( 4.6 mm); ♀ 4.5–5.2 mm ( 4.9 mm).

Male genitalia: Pygofer triangular in lateral view, slightly produced caudad in dorsal half of caudal margin; oval in caudal view, relatively narrow, acutely angulated at lateral sides of opening for gonostyles; diaphragm broad, without armature. Suspensorium rectangular in anterior view, short, widened dorsally, with deep concavity. Gonostyles narrow in widest view, distinctly curved dorsad apically; basal angles short. Phallotheca without ventral slit in ventral view; broad in lateral view; opening on left side; apical process long, produced caudad at base, then downcurved at right angle. Anal tube rectangular in lateral view; ventral margin nearly flat, with one pair of minute protrusions near midlength. Female genitalia: Gonapophyses VIII slender in ventral view, weakly serrated on lateroapical parts. Gonapophyses IX broad in dorsal view, with 15–18 acute teeth in apical 1/3; teeth slightly diverged into asymmetrical two rows. Gonoplacs semicircular in ventral view, broad, wider in apical half.

Distribution. Japan (Honshu).

Remarks. This species can be distinguished by the frontal dark stripes lacking along basal half of median carina, and by the apical process of phallotheca downcurved at right angle. This species may be closely related to Stenocranus planus Yang from Taiwan in coloration and structure but differs in the following features: forewings with CuA 3-branched (4-branched in S. planus ); pygofer narrow in caudal view (wider in S. planus ), apical process of phallotheca downcurved at right angle (curved caudad in S. planus ); gonapophyses IX with about 14–18 teeth (about 10 teeth in S. planus ). The record of Stenocranus ozenumensis Ishihara from the Kansai district is identified as this species based on reconfirmation of the specimens recorded by Kisimoto (1995).

Biological notes. This species is found in low mountainous wetlands. The host plant was reported as Carex olivacea subsp. confertiflora (Boott) ( Cyperaceae ) by Kisimoto (1995).

Etymology. The specific name is dedicated to the late Dr Ryoiti Kisimoto in recognition of his contributions to ecology and taxonomy of Delphacidae in Japan.

Figures

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 3. Habitus, faces, forewings, and hind legs of Stenocranus and Ceratocranus gen. nov. (all males). A, winter form; B, summer form.—A, B, E, S. tonghuaensis; C, F, L, C. agamopsyche; D, G, M, O, C. aurantius sp. nov.; H, S. niisimai; I, N, S. tamagawanus; J, S. kisimotoi sp. nov.; K, S. takasagonis. Scales: 1.0 mm (A–D, H–M), 0.5 mm (N, O).

FIGURE 7. Female genitalia of Stenocranus and Ceratocranus gen. nov. A, B, gonapophysis IX covered with gonapophysis VIII in dorsal view; C–H, apical part of gonapophysis VIII in ventral view.—A, S. takasagonis; B, C. agamopsyche; C, S. niisimai; D, S. tamagawanus; E, S. sapporensis; F, S. kisimotoi sp. nov.; G, S. fallax; H, C. aurantius sp. nov.

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.