Megaplectes bicornis, Watanabe, 2025

Megaplectes bicornis sp. nov.

[New SJN: Futakobu-oo-togari-himebachi]

( Figs. 38A–I, 39A–D, 76C, H, 79I)

Type series. Holotype: JAPAN, KPM-NK 103052 , F, Honshu, Tochigi Pref., Nasushiobara City, Amayu , 2. XI. 2011, E. Katayama leg. Paratype: JAPAN: KPM-NK 103053 , F, Nagano Pref., Ueda City, Sugadaira-kogen , 3–26. IX. 2014, S. Shimizu leg. (MsT) ; KPM-NK 103054 , M, ditto, 1–23. VIII. 2015 .

Description. Female (n = 2). Body punctate and polished; covered with setae; body length 13.7 mm.

Head 0.6–0.65 (HT: 0.6) × as long as wide in dorsal view. Clypeus 2.5–2.55 (HT: 2.5) × as wide as long; slightly convex in lateral view; densely punctate; punctures partly united into groove-like foveola; lower margin subtruncate or sometimes slightly concave medially in frontal view, blunt in lateral view. Face 0.25 × as long as minimum width; weakly convex medially; densely punctate; punctures large, ISP shorter than PD. Frons largely concave above antennal sockets; with pair of horns; largely irregularly rugose except for smooth area just above antennal sockets and median longitudinal groove; horns projected upwards ( Figs. 38D, 76C, H). POL 0.8–1.0 (HT: 1.0) × as OD. OOL 1.3–1.5 (HT: 1.5) × as OD. Gena and occiput densely punctate. Dorsal profile of gena slightly convex; width gradually narrowing posteriorly ( Fig. 38E). Occipital carina complete. Malar space 1.0–1.1 (HT: 1.1) × as long as basal width of mandible. Mandible flat at base; lower tooth equal in length of upper tooth. Antenna with 34–35 (HT: 35) flagellomeres; apical part flattened below and tapped to slender apex. FL I 1.6–1.7 (HT: 1.7) × as long as maximum depth in lateral view, 0.8–0.85 (HT: 0.85) × as long as FL II.

Mesosoma densely punctate ( Fig. 38F). Epomia short; dorsal end situated on collar. Mesoscutum with short and weak notaulus. Mesopleuron with smooth area around speculum; punctures partly united into groove-like foveola. Epicnemial carina present laterally and ventrally. Sternaulus deep in anterior 0.5 of mesopleuron. Metapleuron reticulate rugose; with complete juxtacoxal carina. Propodeum largely irregularly rugose; anterior transverse carina absent; posterior transverse carina complete; lateromedian longitudinal carina largely indistinct; lateral longitudinal carina partly present; pleural carina complete; area superomedia indistinct; apophysis weak and obtusely projected ( Fig. 38H); spiracle oval. Fore wing length 11.2–11.3 (HT: 11.2) mm. Areolet as long as maximum width; width gradually narrowing anteriorly; received vein 2m-cu at slightly beyond to middle ( Fig. 38G). Fore wing vein 1cu-a antefurcal to vein M&RS ( Fig. 38G). Nervellus subvertical; intercepted posterior to middle. Hind femur densely punctate; 5.3–5.4 (HT: 5.3) × as long as maximum depth in lateral view. Tarsal claws simple.

Metasoma finely punctate. T I 1.55–1.6 (HT: 1.6) × as long as maximum width; smooth and finely rugose basally and laterally; apical area densely punctate except for smooth area of postero-median part; punctures of this area partly united into longitudinal or oblique groove-like foveola ( Fig. 38I); latero-median carina largely absent except for basal part; dorso-lateral carina largely indistinct. T II 0.65 × as long as maximum width. Thyridium present; close to anterior margin of T II; depressed; ca. 2.0 × as wide as length. Ovipositor sheath 0.8 × as long as hind tibia, 1.35–1.45 (HT: 1.35) × as long as T I. Ovipositor straight; apex sharp and without minute teeth dorsally; apex of lower valve with teeth ( Fig. 79I).

Colouration ( Figs. 38A–I). Body (excluding wings) black to blackish-brown. Setae brown to blackish-brown. Subapical part of mandible tinged with reddish-brown. FL VI to FL X (or XI) with white markings. Ventral surface of flagellum, fore and mid legs, membranous parts of metasomal sternites partly tinged with reddish-brown. Apex of ovipositor sheath yellowish-brown. Ovipositor reddish-brown. Wings brownish-hyaline. Veins and pterostigma blackish-brown except for yellowish-brown wing base.

Male (n = 1). Similar to female ( Figs. 39A–D). Body length 12.4 mm. Clypeus 2.9 × as wide as long. Malar space 0.55 × as long as basal width of mandible. Antenna not flattened below and tapped; with tyloids on FL X to FL XIV ( Fig. 39D). Lateromedian longitudinal carina of propodeum distinct between base of propodeum and posterior transverse carina; area superomedia with parallel sides. OOL 1.25× as OD. T I 2.35 × as long as maximum width. T II 0.8 × as long as maximum width. FL IX to FL XII with white markings.

Distribution. Japan (Honshu).

Bionomics. Unknown.

Etymology. The specific name is Latin “ bi ” (two) plus “ cornis ” (horn), referring to a pair of frontal horn.

Remarks. This species can be easily distinguished from other species by the frons with a pair of horns.