Plateros magnicauda Kazantsev, sp.n.

Figs 40, 143–144.

MATERIAL: Holotype, ♂, [N] Vietnam, Hoa Binh Prov., Yen Thai Distr., Lac Thinh, Cuc Phuong N.P., 300 m, 20°23´N 105°34´E, 5–6.V.2002, S. Belokobylsky leg. (ICM); paratypes: ♂ and ♀, N Vietnam, Ninh Binh pr., Cuc Phuong N.P., 20°17´57´´N, 105°40´05´´E, 270 m, KL, 4–9.V.2017, A. Weigel leg.; ♂, N Vietnam, Ninh Binh pr., Cuc Phuong N.P., Xom Bong, 390 m, 20°20´56´´N, 105°35´44´´E, primary forest, KL, 12–13.V.2019, A. Weigel leg. (ICM and NME).

DESCRIPTION. Male. Dark brown to black; pronotum, scutellum and elytra orange testaceous (Fig. 40).

Vertex with conspicuous round impression behind antennal prominence. Eyes relatively large, interocular distance subequal to eye diameter. Labrum small, transverse, truncate anteriorly. Palps slender; ultimate palpomeres somewhat longer than wide, slightly widening distally, obliquely truncate and flattened at apex. Antennal sockets separated by minute lamina. Antennae relatively short, not quite reaching elytral half, distinctly narrowing distally, antennomeres 3–10 flattened, feebly dentate; antennomere 3 ca. 2 times longer than antennomere 2 and ca. 1.7 times shorter than antennomere 4; antennomeres 3–11 with dense short suberect pubescence (Fig. 40).

Pronotum transverse, ca. 1.2 times as wide as long, with almost parallel sides, moderately bisinuate basally and noticeably semi-circularly produced anteriorly, with straight sides, short acute, not protruding laterally posterior and widely rounded anterior angles. Scutellum subquadrate, parallel-sided, truncate at apex (Fig. 40).

Elytra relatively broad, ca. 3.2 times longer than wide at humeri, slightly widening from humeri; with four prominent, almost equally developed primary costae, not significantly different from secondary ones; interstices with even rows of subquadrate cells; pubescence dense, short and semi-erect (Fig. 40).

Legs relatively short; femoris relatively broad, femoris and tibiae subequal in length (Fig. 40).

Aedeagus slightly asymmetrical, large; phallobase relatively broad, with a pair of widely separated short sutures; median lobe more or less straight and narrow, slightly widened and noticeably bent distally, with upturned apical cup (Figs 143–144).

Female. Similar to male, but body somewhat broader and eyes distinctly smaller.

Length: 7.9–10.8 mm. Width (humerally): 1.9–2.8 mm.

ETYMOLOGY. The name of the new species is a noun, derived from the Latin for ‘great tail’, alluding to the size of its aedeagus.

DIAGNOSIS. Plateros magnicauda sp.n. may be distinguished from the similarly coloured, i.e., with orange testaceous upperside, congeners by the very large aedeagus, with relatively broad phallobase, bearing a pair of widely separated short sutures and the upturned apical cup of the median lobe (Figs 143–144).

DISTRIBUTION. Northern Vietnam: Cuc Phuong National Park.