Mimochelidonium vietnamicum, Vives, Eduard & Pham, Hong Thai, 2017

Vives, Eduard & Pham, Hong Thai, 2017, New species of Callichromatini Swainson, 1840. (Coleoptera, Cerambycidae). New Cerambycidae from Vietnam. Part 6, Zootaxa 4236 (1), pp. 194-200 : 197

Mimochelidonium vietnamicum sp. nov.

(Fig. 2)

Material studied. Holotype male, 13 mm long and 6 mm wide from Vietnam, Vinh Phu Prov. , Tam Dao N.P., 13- 26.VI.2011, Thai Pham, E. Vives & S. Lingafelter leg. (in VNMN,) . Paratypes: 2 males and 2 females idem; 1 male from Vietnam, Ma Giang , Ha Giang Prov., V.2013, local collector ( EVC) .

Description. Length 13–15 mm. General colour of teguments greenish black, head bluish green, pronotum bright green and elytra golden green on disc and blackish at sides. First four antennomeres bluish and rest of antennae black. Legs and tarsi black with a blue sheen. Abdominal segments black except for chestnut-colored pygidium.

Long narrow head forming a weak anterior rostrum with long wide mandibles. Paraglossae longer than mandibles. Large bulging eyes with fine facets. Antennal bases protruding and separated by a longitudinal furrow from forehead to epistome, which is trapezoidal and finely punctured. Rectangular labrum, chestnut coloured and bearing long setae on free margin. Short, somewhat robust antennae that reach apical quarter in males and apical third in females, short globose scape, strongly punctate. Third antennomere long and robust with two small apical pits at each external side, remaining antennomeres present two external lateral pits that are fused into a single pit after sixth antennomere. Pronotum weakly transverse (45/61) its sides arched and bearing a rounded conical protuberance at middle. Anterior and posterior borders doubly margined, discal area bulging and strongly wrinkled with a shiny golden median longitudinal suture, posteriorly bearing a weak gibbosity at each side. Prosternum short and wide with transverse grooves and grey tomentum. Prosternal projection wide and bordered posteriorly procoxal cavities closed.

Triangular scutellum with a smooth longitudinal band in middle. Short subparallel elytra, rounded weakly projecting humeri, apex of elytra rounded and with a well-defined sutural angle. Suture narrow, not bordered and strongly projecting in centre of disc. Discal area convex with weak folds at base that insinuate two longitudinal ribs. Distinctly short, wide mesosternum, mesocoxal process separating mesocoxae, subquadrate metasternum longitudinally furrowed, both clothed in long white tomentum. Abdominal segments wide and short, finely punctate and clothed in short grey tomentum. Fifth and 6th sternites widely emarginate at posterior border. Short slender legs, fore- and mid-femora dilated in middle, hind-femora long and slender, slightly pedunculate. Fore- and mid-tibiae short and widened apically, hind-tibiae long, flat and weakly sinuate in males. Fore- and mid-tarsi short and strongly dilated in males, flattened in females, hind-tarsi with first segment long and compressed, longer than 2nd and 3rd together. Coxae, trochanters and basal part of fore- and mid-femora clothed in dense golden pubescence that is barely indicated in hind legs.

Male copulatory organ with short curved aedeagus ending in a sharp point, ( Fig. 8), lower lamina shorter than that above. Basal lobe of endophallus with two basal sclerites, median lobe with four or five arched sclerites and a large dorsal plate with a double apex, (Fig. 9), apical lobe with a symmetrical sclerite, sides of apical lobe with two short lobes, (Fig.10). Tegmen short and wide, short styles bearing short apical setae, (Fig. 4).

Diagnosis and remarks. The genus Mimochelidonium was described by Bentanachs (2013) for the single species M. sinense , from South China. When comparing the new genus to Chewchroma Bentanachs & Vives, 2009 and Brevechelidonium Vives, Bentanachs , & Chew, 2009; few analogies were found. Conversely, Mimochelidonium is morphologically very close to the genus Aromiella Podany, 1971 ; with which it shares many characters and geographical distribution. The new species can be distinguished from M. sinense due to its smaller size, parallel elytra projecting from basal suture, different colouration of pronotum, elytra and legs, and the first metatarsal segments shorter and weakly compressed.

Etymology. The specific epithet refers to the country of Vietnam, where the holotype was collected.