Genus Sclethrus Newman

Sclethrus Newman, 1842, Entomologist, 1: 247 (type-species : Clytus amoenus Gory, 1833). loc. cit. - Pascoe, 1869, Trans. Ent. Soc. Lond., ser 3, 3 :618. - Aurivillius, 1912, Coleopt. Cat,, 39 : 417. - Gressitt & Rondon, 1970, Pac. Ins. Monogr, 24 : 279.

Diagnostic characters : head subvertical, hardly exserted; eyes large, prominent, not notched, almost round; antennae slender, very short, scape thicken, segment 3 twice as long as scape, 3 - 6 spined at apex; prothorax elongated, cylindrical; elytra elongated, narrow, apex truncate; legs slender; femora incrassate.

Sclethrus amoenus (GORY)

Maxillary and labial palpi helvus; entire head black with 2 bluish pubescent dots behind eyes; prothorax black; middle and base of latero-dorsal of pronotum with 2 bluish mark at each side, another bluish spots beside fore coxal cavity; interior half of prosternum fusco-castaneous; antennae castaneous, scape black; scutellum albus; elytra pitchy, 1/4 of base with a very small submedian bluish spots; apical half of elytral disc with 2 narrow transverse bluish stripes, 5/9 of basal half with tawny bristles, 4/9 apical half with blackish fuscous tomentum; undersurfaces fuscous-castaneous; posterior half of pro-and mesosternum with a narrow band of albus pile; ventral of metasternum with golden tawny pile; episternum of metathorax with dense velutineous bluish-albus pubescence; similar pubescence also present on latero-posterior of 1st abdominal segment; femora bright ferrugineous-testaceous; tibiae and tarsus fuscous; apex of tibiae clothed with golden bristles, mid and hind pairs with additional blusih-white pubescence.

Head feebly raised between antennal insertion, impubis except for a few scattered long tawny bristles; inner margin of antennifer strongly ridged; clypeus convex anterior-posteriorly, glabrous; frons same plane as cypeus, oblique, sunken, lateral margin with gena well-defined, anterior with a triangular glabrous raised are that carinate medianly to posterior, distantly punctate; gena parallel-sided, constricted below eyes, exserted, as deep as eyes; the latter large, bulging, feebly notched at dorsal; temple goffered; vertex longitudinally puncto-striate with a weak median carina, tomentose; gula with few crescentric striations. Antenna very short, extended a little beyond prothorax; filiform; scape glabrous, diameter distinctively bigger than successive segments; 3 twice as long as scape; 5 - 11 subequal, all a little longer than 4; 8 - 11 gradually shorten, the longest about half of 4; segment 3 & 4 acutely spine endoapically. Prothorax elongated, cylindrical, very much exserted anterior of fore coxae; apex with an annular ring at margin and a broad glabrous annular band behind it; slightly more than 2 X as long as wide; side weakly convex, latero-anterior with a protuberance, sometimes parallel-sided; pronotum with 2 glabrous longitudinal stripe side of median, extended to 1/3 from apex, not reaching basal margin at posterior, the bluish mark placed on this stripes; basi-median with a similar glabrous stripe but with few coarse granules on it, attenuate posteriorly, sometimes these stripe abscence and being replaced by subnitid surface; disc coarsely granulate especially on the basal half, area between the granules finely and densely microgranulate; entire surface impubis except few long tawny bristles. Scutellum relativley small, triangular; apex acute. Elytron 6.5 X as long as broad; dorsal flate, side and 1/4 of apex strongly convex; apex truncate; 5/8 f basal half coarsely punctate, punctures deep and piliferous; setae very long; 3/8 of apical half densely punctulate, tomentose; 1/8 of apical tip somewhat less punctulate, subgalbrous; bluish-white transverse stripe on disc made of few rows of flattened setae; epipleura sinuate. Undersurfaces : anterior half of prosternum glabrous, posterior half pilose; mesothorax exserted, pilose ventrally, episternum of mesothorax sparsely punctate, subglabrous; metasternum densely punctulate; abdominal sterna subinvestitus, pubescence scarce, finely punctulate, denser on 1st and 2nd basal segments. Legs : fore and mid femora fusoform; hind femora gradually clavate, apical tip constricted, apex barely or not extended beyond elytral apex; all femora glossy, setaceous at ventral; tibiae glossy, setaceous; first hind tarsal segment only little longer than 2+3 united.

Measurement : Length 11.0 - 21.0 mm; breadth 2.0 - 3.0 mm.

Distribution : Sarawak; Singapore; Sumatra; Philippines; North Vietnam; Hainan Is.; Laos.

Known habitat : in burned clearing; peat swamp forest.

Material examined : [483] Simunjan, Samarahan Div., 12.X.1995, Besar Ketol (UNIMAS Coll.); 17 specimens in SM Coll. : Matang Road, Kuching Div., 23.IV.1914; Kuching, Kuching Div., 12.V.1914; Matang (3200 ft), Kuching Div., 2.VIII.1909; Matang Road, Kuching Div., 1.X.1909; Matang Road, Kuching Div., 14.X.1909; Matang Road, Kuching Div., 16.XII.1909; Kuching, Kuching Div., 30.IV. 1900; Matang Road, Kuching Div., 9.V.1910; Matang Road, Kuching Div., 13.X.1909; Matang Road, Kuching Div., 17.XII.1915; Matang Road, Kuching Div., 10.XI.1909; Matang Road, Kuching Div., 20.XII.1909; Matang Road, Kuching Div., 8.XII.1910; Kuching, Kuching Div., 27.X.1899; Kuching, Kuching Div., 1.XII.1899; Kuching, Kuching Div., 26.VI.1900; Kuching, Kuching Div., 12.XII. 1903.