Cubocephalus nanus, Watanabe, 2025

Cubocephalus nanus sp. nov.

[New SJN: Mame-onaga-togari-himebachi]

( Figs. 20A–H, 76K, 78P)

Type series. Holotype: JAPAN, KPM-NK 91381 , F, Honshu, Fukui Pref., Oono City, Koike , 31. VII. 1982, H. Kurokawa leg.

Description. Female (n = 1). Body polished; covered with setae; body length 5.1 mm.

Head cubic ( Fig. 20A–D); 0.75 × as long as wide in dorsal view. Clypeus 3.0 × as wide as long; slightly convex in lateral view; sparsely punctate dorsally; smooth ventrally; lower margin subtruncate in frontal view, obtuse in lateral view. Face 0.35 × as long as minimum width; slightly convex medially; matt and sparsely punctate. Frons slightly concave above antennal sockets; punctate dorsally; ISP smooth medially, matt laterally; area above antennal sockets transversely rugose; with pair of small smooth areas between areas with punctures and transverse rugae. POL 1.6 × as OD. OOL 1.6 × as OD. Gena and occiput densely punctate. Dorsal profile of gena rounded in dorsal view; width gradually narrowing anteriorly and somewhat abruptly narrowing posteriorly ( Fig. 20D). Occipital carina complete. Malar space 0.5 × as long as basal width of mandible. Mandible flat at base; lower tooth equal in length of upper tooth. Antenna with 20 flagellomeres; not flattened and tapped. FL I 1.25 × as long as maximum depth in lateral view, 0.75 × as long as FL II.

Mesosoma. Pronotum rugose ventrally; punctate dorsally ( Fig. 20F). Epomia absent ( Fig. 20F). Mesoscutum punctate. Notaulus short and weak. Scutellum punctate; flat in lateral view. Mesopleuron sparsely to moderately punctate; with conspicuous smooth area around speculum ( Fig. 20F). Epicnemial carina present laterally and ventrally. Sternaulus deep in anterior 0.3 of mesopleuron. Posterior transverse carina of mesosternum without deep notch and teeth. Metapleuron sparsely punctate ( Fig. 20F); with complete juxtacoxal carina. Propodeum punctate; anterior transverse carina absent; posterior transverse carina complete, inverted U-shaped ( Fig. 20H); lateromedian longitudinal carina absent; lateral longitudinal carina absent; pleural carina complete; area superomedia indistinct; apophysis absent; spiracle round. Fore wing length 4.25 mm. Areolet as long as maximum width; longer than half length of vein 2m-cu; width steeply narrowing anteriorly; received vein 2m-cu at near middle; anterior width as long as half-length of vein 2m-cu ( Fig. 20G). Fore wing vein 1cu-a interstitial to vein M&RS ( Fig. 20G). Nervellus subvertical; intercepted near posterior end of vein. Hind femur reticulate coriaceous; 3.6 × as long as maximum depth in lateral view. Tarsal claws simple.

Metasoma finely coriaceous. T I 1.9 × as long as maximum width; latero-median carina absent; dorso-lateral carina complete. Spiracle of T I behind the mid-length of T I. T II 0.73 × as long as maximum width; finely and sparsely punctate. Thyridium present; close to anterior margin of T II; slightly depressed; ca. 2.0 × as wide as length. Ovipositor sheath 1.3 × as long as hind tibia, 1.8 × as long as T I. Ovipositor strongly upcurved; apex sharp and without minute teeth dorsally; apex of lower valve with teeth ( Fig. 78P).

Colouration ( Figs. 20A–H). Body (excluding wings) black to blackish-brown. Setae silver. Mandible except for teeth, tegula, and membranous part of metasomal sternites yellowish-brown. Clypeus, face, ventral surface of antenna, metasomal tergites more or less tinged with brown. Face with pair of yellowish-brown spots between antennal sockets and eye. Flagellum without white marking. Fore and mid legs yellowish-brown (coxae slightly darkened). Hind trochanter, trochantellus, tibia except for apical part, tibial spurs, and tarsus brown. Ovipositor reddish-brown. Wings hyaline. Veins and pterostigma blackish-brown to brown except for yellowish wing base.

Male. Unknown.

Distribution. Japan (Honshu).

Bionomics. Unknown.

Etymology. The specific name is from Latin “ nanus ”, which means the dwarf.

Remarks. This species resembles Cu. nigriventris in the small body with cubic head, robust antenna, and strongly upcurved ovipositor but can be distinguished by the colouration of legs and the length of the ovipositor (see above key).