Genus Plutonesthes Thomson

Plutonesthes Thomson, 1864, Syst. Ceramb., : 160 (type-species : P. rufipennis Th., 1864) loc. cit, - Lacordaire, 1869, Gen. Col., 8 : 522 (loc. cit.). - Pascoe, 1869, Trans. Ent. Soc. Lond., ser 3, 3 : 577.

Diagnostic characters : head exserted, subhorizontal; eyes deeply emarginate; frons and vertex subfastigate; antennal support distant; antennae shorter than body, 3 & 4 subeylindrical, 5 - 10 (11 missing) clavate; prothorax strongly constricted behind apex; elytra elongated, pyriform, gradually widen towards apex, tip broadly rounded; side incurved near base; femora peduncle-clavate.

Key to species of Plutonesthes in Sarawak

1.     Prothorax black with orange pubescence near base. - amoena PASCOE, 1869
Prothorax entirely brownish-orange, glossy, sparsely punctate, bristles scattered -  crocata PASCOE, 1866

Plutonesthes amoena PASCOE

Body black; posterior of pronotum covered with orange pubescence; antennae fuscous, clothed with minute blackish pubescence; elytra fusco-castaneous, closely clothed with hirsute orange-red pubescence; undersurfaces pitchy, almost glabrous; legs fusco-castaneous.

Head exserted, almost horizontal; neck moderately long; base of mandible punctate, punctures oblong; clypeus and frons contigeous; the latter somewhat asperate; lower genal margin dilated, triangular; inner antennifer feebly raised, punctate; area between depressed with a median groove and flanked by 2 carinae. Antenna shorter than body; scape short, barely reaching apical margin of prothorax, coarsely punctate; 3 & 4 subcylindrical, sparsely setaceous, compressed; 3 shorter than 4; 5 obliquely widen towards apex; 6 - 10 (11 missing) extended externally, minutely pubescent. Prothorax constricted behind apex; 2/3 of base concave; side umarmed, subglabrous; pronotum microgranulate. Elytron 8 X as long as broad compared to widest part; soft; only deflexed over metathorax; disc flat, entirely clothed with pilose pubescence; outer margin sinuate a little behind base, gradually widen towards apex; tip rounded; widest at apex. Legs : femora successively longer with hind femora longest, peduncle rather long, incurved, setaceous.

Measurement : Length 8.0 - 10.0 mm; breadth 1.5 - 2.5 mm at apex (1.2 - 2.0 mm at base)

Distribution : Sarawak; Singapore

Material examined : 2 ex. (sex unknown) Mt. Merinjak (2200 ft), 28.V. 1914 (SM Coll.); Kuching, Kuching Div., 22.V. 1900 (SM Coll.).

Plutonesthes crocata PASCOE

Plutonesthes crocata Pascoe, 1866, Proc. Zool. Soc. Lond., : 514; 1869, Trans. Ent. Soc. Lond., ser 3, 3 : 577. Aurivillius, 1912, Coleopt, Cat., 39 : 290.

Note : the only specimen in Sarawak Museum is not in good condition for description. However, coloration of prothorax alone is sufficient for positive diagnostic identification.

Material examined : 1 ex. (sex unknown) Mt. Merinjak (2200 ft), 27.V.1914 (SM Coll.).