Margarinotus (Grammostethus) taiwanus, Mazur, 2008

Mazur, Sławomir, 2008, New records of histerid beetles (Coloeptera: Histeridae) from Taiwan, with description of a new species, Baltic Journal of Coleopterology 8 (1), pp. 89-95 : 89-95

Margarinotus (Grammostethus) taiwanus sp.

nov. ( Figs. 1-10)

Body ( Fig. 1) elongate-oval, convex, black and shiny. Dorsal side finely and rarely punctulate, sometimes the elytra more coarsely punctate. Forehead a little concave medially. Frontal stria complete, subcariniform, arcuate medially or feebly and outwardly bent at middle. Mandibles convex, extremely finely punctulate. Scapus and funiculus pitch-brown, antennal club tomentose, with two distinct sutures.

Pronotum ( Fig. 2) rounded laterally. Marginal pronotal stria complete at sides, widely interrupted behind the head and replaced here by an apical stria. Lateral stria distinct, incised and feebly crenate, a little sinuous basally, united with the apical stria. Pronotal margins between marginal and lateral stria weakly swollen. Hind pronotal angles with a shallow, longitudinal impression along the lateral stria. Pronotal base with an indistinct, round fovea in front of scutellum. Epipleural fossete of elytra flat or feebly concave, covered with some coarse punctures along outer margin. Marginal elytral stria absent. Marginal epipleural stria complete. External subhumeral stria complete, deeply incised. There is sometimes an additional row of elongate punctures or shortened stria between the subhumeral and first dorsal stria. Oblique humeral stria present on basal 1/4. Dorsal striae incised, 1-4 complete or the 4th one abbreviated at base or marked here as a row of elongate punctures). Fifth dorsal stria abbreviated basally, not reaching the middle of elytra and sometimes with a short, arcuate rudiment at elytral base. Sutural stria a little longer, present on apical half of elytra.

Pygidial segments a little convex ( Fig. 3). Propygidium feebly, shallowly concave at sides, its surface very densely and coarsely (0.1 - 0.5) punctured. Punctation of pygidium similar to propygidial one.

Prosternal lobe ( Fig. 4) round, distinctly margined anteriorly, shallowly and finely punctulate, more coarsely at sides. Prosternal keel very finely punctulate, with two short carinal striae at base, reaching to 1/3 of prosternal length. Lateral prosternal striae distinct, divergent anteriorly. Mesosternum feebly emarginate at anterior margin, very finely and rarely punctulate. Marginal stria complete, subcariniform, reaching the mesometasternal suture but not united with lateral metasternal striae. Meso-metasaternal suture subcariniform, a little sinuate medially. Metasternum as punctulated as mesosternum. Median line fine. Metasternal apex in front of hind coxae with short, impressed fragments of apical line. Lateral metasternal stria subcariniform, joining the meso-metasaternal suture, extending obliquely and posteriorly, united arcuately with oblique stria which extends inwards from the middle of metasternal-metepisternal suture. Lateral disc of metasternum covered with large, round punctures. Intercoxal disc of 1st abdominal sternum distinctly margined laterally.

Legs paler as body, pitch-brown, a little expanded. Foretibia ( Fig. 5) with 4 dents on outer margin, the 1st one enlarged, with 3 spines.

Length: total 5.0 - 6.0 mm, PE: 3.5 - 3.8 mm. Width: 3.2 - 3.6 mm.

The genital structure of the male as figured ( Figs. 6-10).

Material examined: Holotype B&, TAIWAN; Nantou: Tatachia , 23~ 30-VI-2007, C.-S. Tung [ TARI].

Paratypes: Three specimens of both sexes, data as for holotype [ TARI, one of them deposited in CHSM]; HUALIEN: Hsinpaiyang , 07~ 14-IV-2007, 1 @&, leg (?). Y.-F. Hsu [ TARI] .

Distribution: Taiwan.

Diagnosis: This species may be easily recognized by the curious shape of foretibia, being not multidentate, not only from the Taiwanese species ( Ōhara, 1999: 6) but also from the remaining representatives of the subgenus Grammostethus Lewis as defined by Ōhara (1989: 36-37).