Yimnashana wakaharai, Yamasako & Hasegawa & Ohbayashi, 2012

Yamasako, Junsuke, Hasegawa, Michiaki & Ohbayashi, Nobuo, 2012, Description of a new species of the genus Yimnashana (Coleoptera: Cerambycidae) from Laos, Acta Entomologica Musei Nationalis Pragae 52 (1), pp. 229-235 : 231-234

Yimnashana wakaharai sp. nov.

( Figs. 1–9 )

Type locality. The foot of Phou Pan (Mt.), Ban Saleui, Houa Phan Prov., Laos [20°13′N and 103°59′E, ca. 1500 m a.s.l.].

Type material. HOLOTYPE: J, ‘[ LAOS] Mt. Phou Pan / Ban Saleui , Xam Neua / Houa Phan Prov. / Alt. ca. 1,400– 1,500 m / 27. IV–11. V, 2007 / J. Yamasako leg.’ (EUMJ) . PARATYPES: 1 J, Phou Pan (Mt.), Alt. ca. 1,500–1,800 m, Houa Phan Prov. , Laos, 22. V, 2004, T. Mizusawa leg. ; 1 J 1 ♀, same data as the holotype. (EUMJ and our own collections) .

Description. Male (n = 2, Figs. 1–2 ). Body elongated, pandurate in shape. Body length from vertex to the elytral apices 5.3–5.4 mm, width at humeri 1.6 mm.

Body black. Antennae, elytra and legs dark brown with sparse suberect setae which vary from grayish to blackish. Head sparsely provided with grayish pubescence. Pronotum covered with black pubescence. Elytra covered with grayish ochre pubescence with two black maculae at base and behind middle, of which the basal one is inverted triangular in shape, the second one forms a transverse band of which anterior margin is emarginated to 1/4 of its width at the center. Femora and tibiae with sparse grayish pubescence.

Head slightly narrower than pronotum, roughly punctured; frons well convex. Eyes almost subdivided into two lobes; lower lobe well prominent, about 0.6 times as long as gena, transverse, about 0.6 times as long as wide.

Antennae about 1.5 times as long as body length, surpassing elytral apices at apices of seventh segments; relative lengths of each segment as follow: 1.2: 0.3: 1.1: 1.2: 1.0: 0.9: 0.9: 0.9: 0.8: 0.8: 0.9; scape elongated cuneiform, well thickened apicad, without cicatrix, slightly longer than the third and almost same in length as the fourth.

Pronotum cylindrical, about 1.1 times as long as wide, weakly convex above, with small projection on each lateral side just behind middle; disk with a longitudinal high swelling on anterior half of middle, and a pair of hook-like tubercles near middle; posterior margin slightly narrower than anterior margin, distinctly narrower than humeral width of elytra.

Scutellum wide, ligulate in shape.

Elytra about 0.6 times as long as body length, 2.1 times as long as conjoint width across humeri, 2.2 times as long as pronotal length, widest at apical third; sides slightly dilated laterad from weakly projected humeri toward apical third, thence arcuately narrowed toward rounded apices; disk weakly depressed behind humeri, thence roundly convex above, highest near apical third.

Legs long and slender; mesotibiae without distal notches on anterior margin; relative lengths of metatarsal segments from the basal to the third and claws: 2.5: 1.7: 2.0: 3.8.

Male genitalia (n = 1, Figs. 3–9 ). Tegmen in dorsal view slender triangular, widest behind middle, weakly curved ventrad in lateral view. Lateral lobes in dorsal view thick and short, about 1/7 length of tegmen, evenly and slightly narrowed apicad, with some long setae near apices and a few short setae on latero-dorsal side; apices rounded. Ringed part in dorsal view expanded laterad behind middle of tegmen, thence arcuately narrowed basad.

Median lobe in lateral view weakly curved ventrad, and reflexed dorsally near apex; apex roundly acuminated in ventral view; median struts dehiscent from before middle.

Endophallus in lateral view weakly curved dorsally, about 1.5 times as long as median lobe. MPH with a well-developed swelling on ventral side near middle, evenly covered with rounded sclerites which are small and uncoloured. APH narrow, elongate, cylindrical, densely covered with obtuse sclerites, provided with AS which is consisted of a long rod like sclerotized sclerite, with a single ED on base.

Female (n = 1, partly broken). Body length 5.8 mm, width at humeri 1.7 mm. Similar to male in general appearance. Body slightly thicker than male. Antennae about 1.3 times as long as body length, surpassing elytral apices at bases of tenth segments.

Differential diagnosis. This new species is easily distinguished from other congeners because it lacks spinous tubercles on the elytral base. See also the Key.

Etymology. The species epithet is dedicated to Mr. Hiroyuki Wakahara, a resident of Vientiane, who kindly offered us every facility during the fieldwork in Laos.

Biological note. This species was collected from a thin dead branch of a broad leaf tree in only a narrow area of a small basin located at the foot of Phou Pan (Mt.) (ca. 1,500 m a.s.l.).

Remark. Five species of four genera of the tribe Gyaritini are known from Laos ( RONDON & BREUNING 1970), but the species of the genus Yimnashana is first recorded from Laos here.

Figures

Figs. 1–2. Male habitus of Yimnashana wakaharai sp. nov. (holotype): 1 – dorsal view; 2 – lateral view.

Figs. 3–9. Male genital organ of Yimnashana wakaharai sp. nov. (holotype): 3 – tegmen in dorsal view; 4 – tegmen in lateral view; 5 – lateral lobes in ventral view; 6 – median lobe in dorsal view; 7 – median lobe in lateral view; 8 – apex of median lobe in ventral view; 9 – median lobe with endophallus in lateral view.