Lathomicrus sabahensis, Jałoszyński, Paweł, 2011

Jałoszyński, Paweł, 2011, Two new species of Lathomicrus Jałoszyński (Coleoptera, Staphylinidae, Scydmaeninae) from Borneo, Zootaxa 3009, pp. 62-68 : 62-68

Lathomicrus sabahensis sp. n.

( Figs. 4 , 7, 8 )

Type material. Holotype: MALAYSIA (Borneo): ♂, two labels: " SABAH: Poring Hot \ Springs, 500 m \ 7.V.1987 \ Burckhardt - Löbl" [white, printed]; " LATHOMICRUS \ sabahensis m. \ det. P. Jałoszyński, 2011 \ HOLOTYPUS " [red, printed] ( MHNG).

Diagnosis. Body length ca. 0.7 mm; distal part of aedeagus narrowly subtriangular and with broadly rounded apex, in lateral view apex strongly curved ventrally.

Description. BL 0.69 mm. Body of male ( Fig. 4 ) strongly convex, elongate, with shallow but distinct constriction between pronotum and elytra, very glossy, dark brown, covered with yellowish vestiture, legs and antennae slightly lighter.

Head broadest at large, coarsely faceted and strongly convex eyes, HL 0.08 mm, HW 0.19 mm; vertex and frons confluent and weakly convex, clypeal area weakly deflexed, subtrapezoid in shape; supra-antennal tubercles barely marked, frontal glands distinct, each longitudinally oval and nearly adjacent to mesal margin of compound eye. Punctures on dorsal surface of head very fine, barely noticeable at 100x magnification; setae short and sparse, nearly recumbent. Antennae very slender and with weakly enlarged antennomere IX, so that antennal club appears 2-segmented; AnL 0.28 mm; antennomeres I–II each about twice as long as broad; III barely noticeably longer than broad; IV–VII each slightly elongate, VIII about as long as broad, slightly shorter than VII and much shorter than IX; IX about as broad as long; X slightly transverse; XI slightly shorter than IX–X together, about 1.5x as long as broad.

Pronotum subrectangular, broadest in anterior 1/4; PL 0.21 mm, PW 0.29 mm; anterior margin concave; lateral margins slightly S-shaped, broadly rounded in anterior 1/3, slightly convergent up to middle and nearly straight and parallel in posterior half; hind angles right and acute; posterior margin shallowly bisinuate; base of pronotal disc with four small but deep and sharply marked foveae located close to hind angles, internal foveae connected by sharply marked but shallow transverse groove separating posterior 1/5 of pronotum; both anterior and posterior parts of pronotal disc separated by groove are convex; area on each side between lateral fovea and lateral margin only slightly impressed. Punctures on entire pronotal disc slightly more distinct than those on head, noticeable at 60x magnification, small and shallow but clearly marked and dense; setae sparse, moderately long, suberect.

Elytra strongly convex, oval, broadest between anterior 1/3 and middle; EL 0.40 mm, EW 0.34 mm, EI 1.19; base of each elytron with deep but very short impression and very small basal fovea located in middle between scutellum and humerus; humeral carina very fine, as long as 1/6 of EL; apices of elytra separately rounded. Punctures slightly more distinct than those on pronotum, very shallow and with diffuse margins, separated by spaces equal to puncture diameter; setae similar to those on pronotum.

Legs moderately long and slender; all tibiae straight.

Aedeagus ( Figs. 7, 8 ) in ventral view drop-shaped with subtriangular, rounded apex strongly curved ventrally in lateral view; AeL 0.13 mm. Endophallus lightly sclerotized and relatively simple; parameres slender, not exceeding apex of median lobe, with entire apical parts expanded; each paramere bearing three setae.

Female. Unknown.

Distribution. East Malaysia (Borneo: Sabah).

Etymology. Locotypical, after the state Sabah of Malaysia.

Remarks. Lathomicrus sabahensis is similar in size to L. sumatranus , but clearly differs in proportions of the body parts. The elytra in the new species are stouter, their EI is 1.19, while in L. sumatranus their EI is 1.27. Furthermore, the apical part of the aedeagus in the latter species is distinctly curved dorsally, while in L. sabahensis (and L. sarawakensis ) it is curved ventrally.

Figures

FIGURES 3 – 4. Habitus of holotype males. 3 ― Lathomicrus sarawakensis sp. n.; 4 ― Lathomicrus sabahensis sp. n. Scale bars: 0.2 mm.

FIGURES 5 – 8. Aedeagus in ventral (5, 7) and lateral (6, 8) views. 5, 6 ― Lathomicrus sarawakensis sp. n.; 7, 8 ― Lathomicrus sabahensis sp. n. Scale bars: 0.05 mm.