Ceratocranus, Fujinuma & Hayashi, 2025

Fujinuma, Satoshi & Hayashi, Masami, 2025, Taxonomic revision of Japanese Stenocranus (Hemiptera: Fulgoromorpha: Delphacidae), Zootaxa 5706 (3), pp. 301-336 : 330

Ceratocranus gen. nov.

Type species: Stenocranus agamopsyche Kirkaldy, 1906 , here designated.

Description. Vertex distinctly projected beyond eyes, about 1.7× as long as wide; anterior margin angulate; lateral margins subparallel; carinae distinctly ridged except median carina obsolete; submedian carinae meeting on fastigium. Frons about 3.0× as long as wide, widest near midlength, narrowed in apical 1/3; median carina forked in apical 1/3. Rostrum distinctly exceeding mesocoxae. Antennae terete; segment I slightly longer than wide; segment II about 4.3–4.5× as long as wide. Pronotum about 0.8× as long as vertex, about 1.2× as wide as head; carinae distinctly ridged; lateral carinae diverged posteriad, reaching posterior margin. Mesonotum about 2.2× as long as pronotum; carinae distinctly ridged except median carina obsolete near scutellum. Forewings distinctly exceeding abdomen, mostly subparallel, widest at apical 1/3 (near nodal line), rounded apically; ScP+R fork before CuA fork; C1 longer than C5; venation with ScP, RA, and RP unbranched, MP and CuA 3-branched; anal veins fused in basal half of clavus, reaching wing margin before apex of clavus. Metatibiae with two lateral spines. Hind legs with spinulation: tibial apex with 5 (2 + 3) spinules, basitarsus with 7 (2 + 5) spinules, second tarsomere with 5 spinules. Post-tibial spur cultrate, tectiform, shorter than basitarsus, with about 14–20 teeth on posterior margin.

Male genitalia: Pygofer rectangular in lateral view, higher than wide of ventral margin, strongly produced caudad in dorsal half of caudal margin; oval in caudal view, higher than wide, not angulated at lateral sides of opening for gonostyles; diaphragm broad, without armature. Suspensorium rectangular in anterior view, with small protrusion on left dorsal part. Gonostyles sinuate in lateral view, forceps-shaped in ventrocaudal view, very broad; basal angles relatively long. Aedeagus very slender, sinuate. Phallotheca broad in lateral view, terminating into two downcurved processes; opening for aedeagus on right side. Anal tube rectangular in lateral view; ventral margin bearing one pair of processes. Female genitalia: Pygofer nearly as long as gonoplacs in ventral view, distinctly broader than gonoplacs. Gonocoxae VIII narrow in ventral view, mostly subparallel. Gonapophyses VIII slender in ventral view, nearly smooth on lateroapical parts. Gonapophyses IX relatively broad in dorsal view; dorsal margin with trapezoidal teeth in apical 1/3, small concavity before the teeth. Gonoplacs slender in ventral view, mostly subparallel.

Remarks. This new genus is very similar to Stenocranus in coloration and structure but differs in the following features: antennal segment II 4.3–4.5× as long as wide (shorter in Stenocranus ), second tarsomere with 5 spines (usually 4 spines in Stenocranus ), pygofer strongly produced caudad in dorsal half of caudal margin (weaker in Stenocranus ), suspensorium with small dorsal protrusion (absent in Stenocranus ), phallotheca with opening on right side (usually left or caudal side in Stenocranus ), gonoplacs slender (usually very broad in Stenocranus ). The features of pygofer and phallotheca are unique among stenocranine genera and may be regarded as apomorphies. Moreover, the features of the second tarsomere and gonoplacs are shared with two stenocranine genera ( Terauchiana Matsumura and Embolophora Stål distributed in Africa). The slender gonoplacs are likely plesiomorphic as they are common in other subfamilies of Delphacidae ( Fujinuma 2022) . Stenocranus linnapallidus Asche ( comb. nov.) may be also transferred to this genus based on the male genital features.

Etymology. This genus name is masculine in gender and formed by combining Greek words, “ceratos” (horn, referring to long antennae) and “cranus” (head or helmet).