Pronotum convex; inner margin of all tibiae almost straight; no space between tibiae and femora when closed; apical margin of pygidium with a short spinous process in middle part (Fisher 1921).

This new species is most similar to N. kerzhneri (Alexeev, 1975) among its congeners. It can be distinguished from N. kerzhneri based on the following combination of morphological characters: body slender; lateral margin of pronotum slightly curved and narrowed with somewhat distinct sinuation, basal angle rounded; scutellum wider than long; elytra widest at humerus, longer than wide: W/L = 2.60 (width at humerus), W/L = 2.40 (width including laterosternites); median lobe of male genitalia with two pointed apical denticles on each side and lateral margin slightly narrowed. In contrast, N. kerzhneri has the following aspects: stout body; lateral margin of pronotum more roundly curved and rectilinearly narrowed, without sinuation, basal angle angulated; scutellum longer than wide; elytra widest at posterior 5/9, longer than wide: W/L = 2.35–2.40 (width at humerus), W/L = 2.04–2.16 (width including laterosternites); median lobe of male genitalia without apical denticles on each side and lateral margin drastically narrowed (Alexeev 1975; Emeljanov and Medvedev 2008).

Male (Fig. 2): body length: 5.3 mm, width: 1.7 mm.

Figure 2. 

Habitus of Neotoxoscelus petilus sp. nov., holotype, male A dorsal view B ventral view C lateral view. Scale bar: 1.0 mm.

Body slender and elongate, widest at pronotum, dorsal side black without gloss, ventral side black and somewhat glossy. Head (Fig. 3A–D) small and convex, covered with short, recumbent, whitish and dark brownish hairs arranged moderately on vertex and sparsely on frons; longitudinal sulcus rather distinctly dented at vertex and shallowed towards frons; eye large and longitudinally elongate; clypeus somewhat oval and narrow; antenna short; 1^st antennomere stout, cylindrical; 2^nd antennomere stout, fusiform, and slightly shorter than 1^st; 3^rd and 4^th antennomeres almost cylindrical, remarkably narrower than 2^nd and nearly equal in length; 5^th–10^th antennomeres serrated and dilated, each nearly as long as wide; 11^th antennomere narrowed to apex. Pronotum (Fig. 3A, B, D) rugose and punctate, covered with recumbent, dark brownish and whitish hairs, widest at midpoint, wider than long: L/W = 1.45 (width at midpoint), L/W = 1.30 (width at basal fourth); anterior margin arcuately bisinuate and convex at mid part; lateral margin slightly curved from apex to anterior 3/4 and narrowed, with somewhat distinct sinuation; posterior margin arcuately bisinuate and weakly sinuated at mid part; basal angle rounded; lateral carina strongly elevated, arcuately extending from near anterior margin to just posterior to midpoint and exteriorly converging to lateral margin; carinal interspace dented; disc uneven, with laterobasal depressions and projected from base to apex. Scutellum (Fig. 3G) rugose, wider than long (L/W = 1.20), nearly an equilateral triangle; anterior margin slightly convex; lateral margin weakly concave. Elytra (Fig. 2A, C) irregularly rugose and punctate, covered with recumbent, dark brownish, inconspicuous hairs, longer than wide (W/L = 2.60, including laterosternites 2.40), slightly narrower than maximum pronotal width and widest at humerus; anterior margin strongly and narrowly bisinuate; humeral angle rounded; lateral margin slightly concave from humerus to posterior 2/5 and narrowed almost rectilinearly, tapered and slightly arcuate to apex, with feeble marginal teeth; disk slightly flattened; ornamentation remarkable, with whitish hairs arranged as follows: 1^st band somewhat narrow, strongly curved interiorly; 2^nd band eye-shaped, longitudinally subrectangular, extended laterally, linked with 1^st band apically; 3^rd band in posterior 3/5 transversely short and zigzagged; 4^th band in posterior 2/5 transversely long and zigzagged, forming a triangular ring with 3^rd band; 5^th band feebly zigzagged, somewhat far from 4^th. Laterosternites (Fig. 2A, C) ornamented with recumbent, whitish hairs in posterior 3/5 of elytra, seemingly linked with zigzagged band of elytra. Hindwing (Fig. 3H) sclerotized with markedly reduced venation. Prosternum (Fig. 3C) slightly convex, rugose and punctate, covered with recumbent, short, whitish hairs, longer and thicker toward middle. Prosternal process (Fig. 3I) feebly convex, composed of subrectangular microsculpture, rather concentrically rugose, covered with long and thick hairs; lateral margin slightly concave, arcuately narrowed behind anterior coxal cavities, angulated subapically, rounded at apex. Abdominal sternites (Figs 2B, 3E) black and somewhat glossy, covered with overall sparsely recumbent, short, yellowish and whitish hairs; sternite I longest, following sternites each gradually shorter than preceding sternite, except sternite V; lateral part of sternite I and anterolateral part of sternite II remarkably congregated, with rather long, white hairs; anteromedian and anterolateral parts of sternites III–V with remarkable whitish hairs and slightly attenuated toward the apex; sternite V with long and brownish hairs posteriorly, densely congregated in middle. Legs somewhat short; protibia (Fig. 3F) alveolate, widest at posterior 1/3, outer margin slightly convex and crenulated, inner margin slightly curved, with dense yellowish hairs at anterior part and somewhat sparse hairs at posterior part, oblique grooves elongated rather distinctly dented at apex and shallowed posteriorly; all tarsi with brownish tarsal lamella, each tarsomere gradually widened anteriorly. Genitalia (Fig. 4) longer than wide (W/L = 4.75), widest at anterior 1/5, sparsely punctuated dorsally, apical part with oblique grooves ventrally; paramere obliquely narrowed from widest part to apex, with long, yellowish hairs; median lobe with two pointed apical denticles on each side and lateral margin slightly narrowed to apex.

Figure 3. 

Neotoxoscelus petilus sp. nov., holotype, male A pronotum, dorsal view B ditto, lateral view C prosternum D head, frontal view E sternite V and spinous process, ventral view F protibia, dorsal view G scutellum H hind wing I prosternal process. Scale bars: 0.5 mm (A, H); 0.4 mm (B–E); 0.2 mm (F–G, I).

Figure 4. 

Male genitalia structures of Neotoxoscelus petilus sp. nov. A genitalia, dorsal view B ditto, ventral view C apical part of median lobe, dorsal view D ditto, ventral view. Scale bars: 0.4 mm (A–B); 0.1 mm (C–D).

Female. Unknown.

Holotype. ♂, South Korea, Gyeongsangbuk-do province, Cheongsong-gun, Budong-myeon, Sangui-ri, Mt. Juwangsan, ca 550 m alt., 36°23'21.7"N, 129°10'06.9"E, sweeping, 26. VII. 1984, S.J. Suh Coll. (KNU).

Unknown.

South Korea, Gyeongsangbuk-do province.

The specific epithet refers to the slender body shape of the new species.