Nitorus sathulaz, Telnov, 2024

Telnov, Dmitry, 2024, New species and records of Anthicidae Latreille, 1819 (Coleoptera) from Taiwan with a key to Asian Nitorus Telnov, 2007 species with gibbose pronotum, Zootaxa 5507 (2), pp. 285-312 : 306-308

Nitorus sathulaz sp. nov. ( Figures 17–18 )

urn:lsid:zoobank.org:act:DF37A008-F628-46AC-B811-B25072B2ADF7

Type material designated. Holotype ♂, NME: Vietnam- N, 160 km NNW Hanoi, Tuyen Quang prov., 3 km NE from Na Hang, Pac Ban vill. env., 900 m, primary rain forest, 30.V–14.VI.1996, leg. A. Napolov [printed].

Paratypes 2♂ DTC: same label as holotype.

Derivatio nominis. Named from Proto-Germanic ‘sathulaz’ (saddle) to point on the saddle-like impressed, bigibbose pronotum. Noun in apposition.

Measurements, holotype male, total body length excluding partially exposed terminalia 2.2 mm; head length 0.6 mm, head width across compound eyes 0.5 mm, pronotal length 0.5 mm, maximum pronotal width 0.4 mm, minimum pronotal width in basal half 0.2 mm, elytral length 1.1 mm, combined maximum elytral width across midlength 0.8 mm. Male paratypes 2.4 mm long.

Description. Holotype male. Dorsal forebody dark rufous, ventral—pale rufous. Elytra narrowly dark rufous at base including scutellar shield, rest of surface black-brown. Antennomeres 1–6 pale rufous to yellowish, remaining antennomeres dark rufous to brown. Maxillary palpus dark rufous, mesal margin of terminal palpomere pale. Legs dark rufous, tarsi pale rufous to yellowish. Abdomen brown. Head elliptical, slightly longer than wide, slightly convex in dorsal aspect, moderately glossy. Labrum subtruncate at anterior margin. Frontoclypeal suture present, slightly arched (shallowly concave anteriorly). Compound eye small, moderately protruding from lateral outline of head, shorter than rather strongly converging tempus. Head base narrowly rounded. Head dorsal punctures large, irregularly shaped, dense and deep. Intervening spaces on anterior head microreticulate and much narrower than punctures, on posterior head smooth and glossy, generally slightly narrower than punctures. Dorsal cranial setae whitish, sparse, inconspicuous. Antenna extending towards base of elytra when directed posteriad, thickened in apical half. Antennomere three about 1.4× as long as antennomere two. Antennomeres 4 and 5 about same long, each slightly shorter than antennomere three. Antennomeres 8–11 thickened, of them 9–10 distinctly widened distally. Penultimate antennomere, somewhat shortened, about as long as wide. Terminal antennomere slightly asymmetrical, shortly conical, bluntly pointed, about 1.6–1.7× as long as penultimate antennomere, distinctly shorter the combined length of antennomeres 9–10. Penultimate maxillary palpomere slightly lobate at mesal margin distally. Terminal maxillary palpomere strongly securiform. Cranial ‘neck’ less than a third head width across compound eyes, smooth and glossy. Pronotum longer than wide, distinctly narrower than head across eyes, truncate medially at anterior margin. Pronotal disc glossy, bigibbose in dorsal aspect with a deep, saddle-like discal impression separating anterior and basal lobes of pronotum. Lateral margins of anterior lobe strongly protruding laterad (subangular), of basal lobe—widened towards base.Anterior pronotal rim distinct, wide dorsally, laterally and ventrally. Antebasal sulcus moderately wide dorsally, wide laterally. Pronotal punctures present mainly on anterior and basal pronotal humps only, smaller than those on head. Intervening spaces glossy and glabrous, generally as wide as punctures. Basal lobe with large and dense but shallow punctures, intervening spaces glossy and glabrous, narrower than to as wide as punctures. Lateral sides of anterior lobe glossy and glabrous, impunctured, of basal lobe and constriction area—glossy and glabrous, with dense subparallel longitudinal wrinkles. Pronotal setae as those on head, inconspicuous. Scutellar shield lanceolate, apically rounded, glossy and glabrous. Elytra elliptical, about 1.3–1.4× as long as wide, widest at midlength, dorsally strongly convex. Postbasal transverse impression not indicated. Humerus broadly rounded, humeral callosity slightly projecting in dorso-lateral aspect. Apical sutural angle rounded. Elytral surface glossy and smooth, punctures minute, shallow, sparse. Intervening spaces smooth and glossy, much wider than punctures. Elytral setae whitish, rather short, sparse, not fully appressed, inconspicuous. Scattered longer erect tactile setae on elytral disc. Metathoracic wing fully developed (functional). Legs moderately long, sparsely minutely setose. All tibiae somewhat thickened. Protibia somewhat sinuous on both anterior and posterior margin. Metatibia slightly sinuous in distal half, dorsal surface in posterior two-thirds slightly flattened, here densely punctured and with numerous whitish suberect setae. Tibial terminal spurs paired, very short. Basal metatarsomere longer than combined length of remaining metatarsomeres. Penultimate tarsomeres slightly bilobate. Tergite VII truncate at posterior margin. Morphological sternite VII broad, rounded at posterior margin. Aedeagus ( Fig. 18 ) elongate, apex trident-shaped.

Sexual dimorphism. Female unknown.

Differential diagnosis. Nitorus sathulaz sp. nov. appears most similar to N. monstrosicollis (Pic, 1901) from the Greater Sunda islands of Borneo and Sumatra but is specifically different in the shape of the apical portion of aedeagus, the comparatively coarser punctured head dorsum and the anterior pronotal lobe comparatively wider than that in the insular species.

Ecology. Sampled at light at the edge of primary lowland rainforest at 900 m.

Distribution. So far known from northern Vietnam.

Figures

FIGURE 17. Nitorus sathulaz sp. nov., holotype ♂. A—Habitus, dorsal view; B—ditto, lateral view.

FIGURE 18. Nitorus sathulaz sp. nov., paratype ♂. A—Aedeagus; B—ditto, apex, magnified; C—ditto, median portion, magnified [not to scale].