Baiocis sumatranus Beaver & Liu, 2018

Beaver, Roger A., 2018, A review of the genus Baiocis Browne, 1962 (Coleoptera: Curculionidae: Platypodinae), with new species, new synonymy and a key to males, Zootaxa 4434 (3), pp. 481-501 : 490-492

Baiocis sumatranus Beaver & Liu , new species

( Fig. 29 )

Male: Body length 3.3‒3.5 mm, 4.9 ‒5.0 times as long as wide. Body brown, head dorsally, abdomen and hind coxae black, elytra becoming black toward apex, antennae, legs except for tibiae and underside except for abdomen paler. Head with frons flat, shining, weakly rugose with a dark median line above antennal insertions, irregularly punctured with fine punctures above epistoma and near upper margin, but coarse, irregular punctures in middle, punctures with short erect hairs, vertex angularly separated from frons but without a transverse carina. Eyes subcircular. Pronotum 1.6 times as long as wide, widest behind deep femoral grooves, maximum width about 1.4 times minimum, disc smooth, shining, weakly alutaceous close to apical and basal margins, almost glabrous above, a few short hairs laterally, disc with scattered very fine punctures, median line weakly developed except between lateral emarginations. Elytra 2.9 times as long as wide, 1.9 times as long as pronotum, horizontal, the sides subparallel, widest about middle, tapering slightly posteriorly without constriction before apex, the lateral margins with 4 to 5 serrations close to apex, not visible from dorsal view, each serration with a single hair; disc smooth, shining, glabrous except for a few erect hairs posteriorly, striae not impressed, finely punctured, the punctures elongate on first striae; interstriae indistinct with very fine scattered punctures; disc ending in a carinate rim forming a deep U-shaped emargination, posterolateral processes long, ventrally curved, tapering with pointed apex. Declivity narrow, lunate, shining in a small triangular area on each side of suture and in the apical 2/3, intermediate part matt. Abdomen with median process of first ventrite with a weakly bifid apex, second to fourth ventrites shining, each with a row of erect hairs at the sides, not extending across the median third, apical margins slightly thickened; fifth ventrite concave with thickened margin, a single pair of hairs towards the apex. Anterior margin of impression on metaventrite and metanepisternum with a single small tooth on metanepisternum. Metacoxa with a spine on its inner margin projecting posteriorly.

Female: Unknown.

Holotype: Male: [ INDONESIA], Sumatra, Jambi, Gunung Kerinci , 1800-2100m, 6-7.iii.1991 (Bocák & Bocáková). (Deposited in NHMB)

Paratypes: Male: 3 specimens: as holotype (2) ( NHMB, RAB); Sumatra, Jambi, Kerinci, Seblat N.P., 7 km E Kayuaro, Mt. Tujuh, 1750 ± 250m, 25.ii.‒2.iii. 2003 (Dembický) (1 male) ( RAB).

Etymology: The specific name refers to the Indonesian island (Sumatra) on which the species was collected.

Diagnosis: B. sumatranus belongs to a small group of species ( B. incisus , B. inimicus , B. spicatus ) in which the first abdominal ventrite is enlarged to form a median process extending ventrally and posteriorly over the base of the second ventrite. It is distinguished from other members of the group by the angular separation of the frons from the vertex, the bifid apex of the median process of the first ventrite, and the long posterolateral processes of the elytra. It is possible that this species is the male of Baiocis angustulus (Schedl) , described from a single female collected in the neighbouring island of Java. However, at present, the male and female cannot be definitely associated.

Biology: Unknown.

Figures

FIGURES 26–32. Baiocis species. 26‒27. B. orientalis dorsal view: 26, male (2.3 mm); 27, female (2.4 mm). 28. B. pernanulus male (2.3 mm), dorsal view. 29. B. sumatranus male (3.5 mm), dorsal view. 30‒32. B. laosi. 30, male (2.9 mm), dorsal view; 31, female (3.0 mm), dorsal view; 32, male abdomen, lateral view.