Plateros stenohelix Kazantsev, 2021

Kazantsev, S. V., 2021, A review of Plateros Bourgeois, 1879 of Indochina (Coleoptera: Lycidae), Russian Entomological Journal 30 (1), pp. 47-73 : 71

Plateros stenohelix Kazantsev , sp.n.

Figs 63, 181–182.

MATERIAL: Holotype, ♂, NE Laos, Hua Phan prov., Ban Saleui, Phou Pan Mt. , ~ 20°12´N, 104°01´E, 1300–1900 m, 1– 31.05.2011, C. Holzschuh leg. ( ICM).

DESCRIPTION. Male. Dark brown to black; pronotum, except at disk, and elytra orange testaceous ( Fig. 63).

Vertex with two conspicuous minute round impressions behind antennal prominence. Eyes relatively small, interocular distance ca. 1.5 times greater than eye diameter. Labrum small, transverse, rounded anteriorly and minutely emarginate medially. Palps slender; ultimate palpomeres not much longer than wide, widening distally, obliquely convex and flattened at apex. Antennal sockets separated by narrow lamina. Antennae relatively short, hardly attaining to elytral middle, strongly dentate; dent of antennomere 6 ca. 2 times shorter than stem; antennomere 3 triangular, ca. 1.25 times wider than long, ca. 3.3 times longer than antennomere 2 and ca. 1.3 times shorter than antennomere 4; antennomeres 3–11 with short erect pubescence ( Fig. 63).

Pronotum transverse, ca. 1.5 times wider than long, with straight sides, slightly bisinuate basally and somewhat semi-circularly produced anteriorly, with acute, noticeably protruding laterally posterior and rounded anterior angles. Scutellum transverse, parallel-sided, slightly triangularly incised at apex ( Fig. 63).

Elytra long, ca. 3.3 times longer than wide at humeri, almost parallel-sided; with four prominent, almost equally developed primary costae, not much different from secondary ones; interstices with even rows of regular subquadrate cells; pubescence dense, short and decumbent ( Fig. 63).

Legs slender; femoris and tibiae narrow, subequal in length ( Fig. 63).

Aedeagus asymmetrical, with narrow phallobase and contiguous phallobasal lateral plates; median lobe narrowly spiral, considerably widened and toothed in distal third, with distinct blunt tooth at proximal third ( Figs 181–182).

Female. Unknown.

Length: 7.5 mm. Width (humerally): 1.8 mm.

ETYMOLOGY. The name of the new species is derived from the Greek for ‘narrow’ and ‘spiral’, alluding to the structure of the median lobe of its aedeagus.

DIAGNOSIS. Plateros stenohelix sp.n. may be distinguished from the similarly coloured congeners with spiral aedeagi by its narrow spiral ( Figs 181–182).

DISTRIBUTION. North-eastern Laos.