A review of Plateros Bourgeois, 1879 of Indochina (Coleoptera: Lycidae) Author Kazantsev, S. V. text Russian Entomological Journal 2021 2021-03-31 30 1 47 73 http://dx.doi.org/10.15298/rusentj.30.1.07 journal article 10.15298/rusentj.30.1.07 0132-8069 10978325 Plateros gemellus Kazantsev , sp.n. Figs 56 , 183–184 . MATERIAL: Holotype , ♂ , N Vietnam , Na Hang , 160 km NNW Hanoi , NE env. of Na Hang , 150–200 m , 9–14.VI.1996 , A. Napolov leg. ( ICM ); paratypes : ♂ , Vietnam , Hoa Binh Prov. , Mai Chan Distr. , Hang Kia , 1300 m , 20°44´N 104°53´E , 1–2.V.2002 , S. Belokobylsky leg.; 3 ♂♂ and 3 ♀♀ , Vietnam , Hoa Binh Prov. , Yen Thai Distr. , Lac Thinh , Cuc Phuong N.P. , 300 m , 20°23´N 105°34´E , 1–6.V.2002 , S. Belokobylsky leg. ( ICM and ZIN ); ♂ , N Vietnam , Ninh Binh pr., 90 km SW Hanoi , Cuc Phuong N.P. , primates resc. centr., Li-Fa, 20°14´24´´N , 105°42´53´´E , 190 m , 25.IV.2012 , A. Weigel leg.; ♂ , N Vietnam , Ninh Binh pr., Cuc Phuong N.P. , 20°15´30´´N , 105°42´29´´E , 150 m , 6.V.2017 , R. Gerstmeier leg. ( NME ). DESCRIPTION. Male . Dark brown to black; pronotum, scutellum and elytra testaceous; antennomere 2, trochanters and bases of femoris light brown ( Fig. 56 ). Vertex with prominent round impression behind antennal prominence. Eyes large, interocular distance ca. 1.7 times shorter than eye diameter. Labrum small, transverse, convex anteriorly. Palps slender; ultimate palpomeres considerably longer than wide, almost parallel-sided in proximal two thirds, narrowed before apex, obliquely truncate and flattened at apex. Antennal sockets separated by minute lamina. Antennae long, attaining to elytral five sixths, antennomeres 4–10 ramose, with ramus of antennomere 3 ca. 1.5 times shorter than stem, ramus of antennomere 7 ca. 1.7 times shorter than stem; antennomere 3 ca. 2.8 times longer than antennomere 2 and ca. 1.1 times shorter than antennomere 4; antennomeres 3–11 with long erect pubescence (Fig.). Pronotum transverse, ca. 1.6 times wider than long, trapezoidal, bisinuate basally and strongly triangularly produced anteriorly, with straight sides, prominent acute posterior and pronounced blunt anterior angles. Scutellum transverse, parallel-sided, truncate at apex ( Fig. 56 ). Elytra moderately long, only ca. 2.9 times longer than wide at humeri, slightly widening distally; with four almost equally developed primary costae, not much different from secondary ones; interstices with even rows of roundish cells; pubescence scarce, short and decumbent ( Fig. 56 ). Legs slender; femoris and tibiae narrow, subequal in length ( Fig. 56 ). Aedeagus asymmetrical, with narrow phallobase and contiguous phallobasal lateral plates; median lobe spiral, moderately robust, provided with tooth at coil bend and groove at all coil length; not widened in distal third and coil plane forming blunt angle to proximal stem ( Figs 183–184 ). Female . Similar to male, but eyes distinctly smaller and antennae broader and less ramose. Length: 6.1–9.0 mm. Width (humerally): 1.7–2.2 mm . ETYMOLOGY. The name of the new species is derived from the Latin for ‘twin’, alluding to its habitual similarity to P. phoungensis sp.n. DIAGNOSIS. Plateros gemellus sp.n. may be placed near P. propinquus Waterhouse, 1979 , resembling it in habitus, separable by the larger eyes ( Fig. 56 ) and by the details of the aedeagus: longitudinal groove at all coil length, distal third not widened and coil plane forming blunt angle to the proximal part of the median lobe of the aedeagus ( Figs 183–184 ). DISTRIBUTION. Northern Vietnam .