Hexarhopalus (Hexarhopalus) rolandi, Purchart, Luboš, 2010

Purchart, Luboš, 2010, Review of the genus Hexarhopalus Fairmaire, 1891 (Coleoptera, Tenebrionidae, Stenochiinae) from Borneo with description of new species, Zootaxa 2476, pp. 1-13 : 7-8

Hexarhopalus (Hexarhopalus) rolandi sp. nov.

( Fig. 6 )

Type locality. Borneo, Sabah, Crocker Range, Gunung Alab.

Type material. Holotype. ( CRGT): Malaysia, Sabah, Crocker Range, Gunung Alab, 1350 m, 20. 11. 2006, R. Grimm.

Condition of holotype: Right middle tarsus and right front tibia with tarsus missing.

Differential diagnosis. This species most resembles, within the entire genus Hexarhopalus , H. sculptilis Kaszab, 1960 and H. birmanicus Kaszab, 1960 from Myanmar as it has similar corrugated surface of elytra and transversely connected interstriae. It can be distinguished as follows: pronotum longer than broad, oblique indentation in posterior angles large and deep, continuing with shallow groove anteriad, anterior half of pronotum dorso-laterally with two large swellings separated by a large midlongitudinal depression situated in anterior half of pronotum (in both above mentioned species pronotum is approximately as long as broad or little broader, oblique indentation in posterior angles extremely slightly indicated, pronotum without or with only slightly developed swellings and without large midlongitudinal depression).

Description. Size of holotype 10.6 x 4.3 mm. Black, dull, with labrum, maxillary palpi, antenna and tarsi brown. Body elongate oval.

Head smooth, glabrous, shagreened. Narrower than pronotum in ratio 1:1.5. Labrum, clypeus and genae simply and finely punctate. Frontoclypeal sulcus on the base U-shaped, deep, not reaching the clypeal margin. Distance between eyes 1.5 times as wide as their diameter (DV). Ocular sulcus normally developed, deep. Antenna slender, approx. 1.1 times as long as pronotum.

Pronotum glabrous, shagreened, slightly dilated towards the anterior margin, broadest at middle, PW:PL ratio is 1:1.1. Base of pronotum rimmed, very finely, shallowly and relatively densely punctate (size of punctures approximately as large as an eye facet) and obliquely truncate anteriad to posterior angles. Anterior half of pronotum with two large swellings situated dorso-laterally. Between base of pronotum and these swellings one impression at each side. The space between the swellings depressed midlongitudinally. Very deep oblique indentation in posterior angles continuing with lateral shallow groove reaching anterior third of pronotum. Lateral carina weakly developed, only slightly obliterated, bent upwards and creating rim of anterior margin of pronotum. The latter obliterated in the middle.

Elytra elongate oval, dilated posteriad, broadest behind middle and then directly narrowing towards the apex of elytra. 1.45 times as long as its width and twice as long, and 1.5 times as wide as pronotum. The base of the elytra strongly carinated with transverse costa. Elytral suture flat. Elytral striae indicated with more or less regular rows of longitudinal and relatively deep punctures. Elytra interstriae convex, corrugate and irregularly transversely connected, creating an impression of a net-like surface of elytra. Elytral disc slightly convex (LV). Elytral declivity steep. Scutellum triangular.

Prosternum, prosternal process, mesoventrite and metaventrite shiny and as smooth as prothoracic hypomeron. Metaventrite approximately as long as mesocoxa. Abdominal ventrites smooth, shagreened and micropubescent.

Legs smooth, simply and finely punctate, micropubescent. Apical part of tibiae with relatively long yellowish setae underneath. Tarsi sparsely pubescent above and with brush-like yellowish setae underneath.

Distribution. Borneo, Sabah, Crocker Range, Mt. Alab.

Etymology. Named in honour of my dear colleague Dr. Roland Grimm ( Germany), specialist on Tenebrionidae and collector of the type specimen, who kindly provided me with the holotype for description.

Figures

FIGURES 1 – 6. Habitus, dorsal view. 1. Hexarhopalus barclayi sp. nov. (holotype); 2. H. becvari sp. nov. (holotype); 3. H. ferreri sp. nov. (holotype); 4. H. iwani sp. nov. (holotype); 5. H. murudensis sp. nov. (holotype); 6. H. rolandi sp. nov. (holotype).