Mesostrix bimaculata, Mazur, Sławomir & Mokrzycki, Tomasz, 2014

Mazur, Sławomir & Mokrzycki, Tomasz, 2014, Two new species of Mesostrix Mazur, 1994 (Coleoptera: Histeridae) from Southeast Asia, Zootaxa 3755 (2), pp. 197-200 : 197-198

Mesostrix bimaculata sp. n.

( Figs. 1 a–e)

Type locality. Malaysia: Sarawak: Long Lihau.

Type material examined. Holotype, ♂: [ Malaysia] Borneo: Sarawak / Belaga-Distr. Long Lihau / 17.- 21.3.1990; leg. A. Riedel (printed); // Holotype (red label, printed) // Mesostrix / bimaculata sp. n / Det. S. Mazur, 2013 (white label, printed) ( MNSG). Paratype, ♀: same data as holotype ( CHSM).

Description. PE: 2.5–2.6 mm; total: 3.6–3.8 mm. Elytral width: 2.2 mm. Body ( Fig. 1 a) oval, moderately convex, black with aeneous tinge, shiny.

Head finely punctulate, the frons and epistoma concave. Frontal stria present, feebly inwardly arcuate medially, united laterally with the supraorbital one. Labrum transverse, emarginate anteriorly. Mandibles convex, finely punctulate, with one tooth at inner margin and a longitudinal cariniform stria at base. Antennae paler than body, brownish-red, the antennal club tomentose.

Pronotum rounded laterally, narrowed anterad. Marginal pronotal stria present at sides only, the lateral stria complete, incised laterally. Pronotal sides covered with elongate punctures, the punctation densely distributed (0.5–2.0). Pronotal disc finely punctulate. Base of pronotum with irregular rows of round punctures, densely distributed (0.5–1.5) and interrupted in front of scutellum.

Elytra rounded, with red maculae reaching from epipleura to the interval between fourth and fifth dorsal stria. Humeral stria fine. Dorsal striae distinctly incised and crenulate, the striae 1–4 complete, the fifth one almost complete. Elytral epipleura even, rarely punctulate. Epipleural marginal stria complete, carinate basally. Elytral marginal stria complete and deeply impressed.

Propygidium transverse, densely covered with round, flat punctures (0.2–1.2). Pygidium convex, as punctured as propygidium, its margin elevated.

Prosternal lobe ( Fig. 1 b) rounded at apex. Marginal stria crenate and incised, present medially only. Disc rather sparsely covered with moderate punctures (1–3), more coarsely at sides. Prosternal keel triangularly, slightly concave between coxae. Double lateral stria present and divergent anteriorly, carinate at outer side. Anterior margin of mesoventrite very shallowly emarginate. Secondzary marginal stria present in antero-lateral angles only. Marginal mesoventral stria well carinate, trapezoidal, its median part lying close to margin. Disc of metaventrite nearly smooth, very minutely punctulate. Mesometaventral suture as well as median line slightly impressed. Punctation of intercoxal disc similar to that of mesoventrite.

Lateral metaventral stria deeply impressed, extending posteriorly and obliquely, its apical end hamate in front of mesocoxa. Postmesocoxal stria present, deeply carinate, laying almost parallel to the lateral metaventral stria. Lateral disc coarsely but not too densely (1–3) covered with round punctures. First abdominal ventrite as punctured as metaventrite, more coarsely at sides; two lateral striae present, indistinctly united basally.

Legs paler than body, reddish brown. Protibiae with 3(+1) teeth along anterior margin. Tarsal groove S-shaped. Mesotibiae with 3 spinules, the apical one bifid. Metatibiae with two spinules at outer margin.

Male genitalia: aedeagus ( Figs. 1 c–e). Ratio in length of parameres to basal piece about 1.78. Lateral sides of parameres divergent gradually, thence convergent apically at apical fourth. Parameres fused on dorsal surface. Median lobe simple.

Etymology. This species’ name refers to its bicolored appearance.

Distribution. So far known only from the type locality, Long Lihau, Belaga Distr, in Sarawak, Malaysia.

Differential diagnosis. See generic key.

Figures

FIGURE 1. Mesostrix bimaculata sp. n. a) Dorsal habitus; b) Ventral habitus; c) Aedeagus, ventral view; d) Aedeagus, dorsal view; e) Aedeagus, lateral view.