Lathomicrus sarawakensis, 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 sarawakensis sp. n.

( Figs. 3 , 5, 6 )

Type material. Holotype: MALAYSIA (Borneo): ♂, two labels: " SARAWAK, 5.6.68 \ Mt Santubong \ nr. Kuching 600m \ G. Rotschild" [white, printed]; " LATHOMICRUS \ sarawakensis m. \ det. P. Jałoszyński, 2011 \ HOLO- TYPUS " [red, printed] ( MHNG).

Diagnosis. Body longer than 0.7 mm; distal part of aedeagus narrowly subtriangular, with trapezoidal apex, in lateral view apex slightly curved ventrally.

Description. BL 0.76 mm. Body of male ( Fig. 3 ) strongly convex, elongate, with shallow but distinct constriction between pronotum and elytra, moderately glossy, light brown, covered with yellowish vestiture, legs and antennae slightly lighter.

Head broadest at large, coarsely faceted and strongly convex eyes, HL 0.09 mm, HW 0.20 mm; vertex and frons confluent and weakly convex, clypeal area strongly 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 very sparse, recumbent to suberect. Antennae very slender and with distinct 3-segmented club, AnL 0.33 mm; antennomeres I–II each about twice as long as broad; III only slightly longer than broad; IV–VII each distinctly longer than broad; VIII slightly longer than broad, distinctly shorter than VII and IX; IX about as long as broad; X slightly transverse; XI distinctly shorter than IX–X together and about 1.7x as long as broad.

Pronotum subrectangular, broadest in anterior 1/4; PL 0.23 mm, PW 0.30 mm, anterior margin in dorso-frontal view distinctly 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 nearly straight; base of pronotum with four shallow and small foveae located close to hind angles, internal foveae connected by sharply marked but shallow transverse groove separating posterior 1/5 of pronotum. Pronotum anterior to basal groove strongly convex, posterior portion flattened; area between each lateral fovea and lateral margin distinctly impressed. Punctures on entire pronotal disc as fine as those on head; setae sparse, moderately long, suberect.

Elytra strongly convex, oval, broadest slightly anterior to middle; EL 0.45 mm, EW 0.35 mm, EI 1.29; base of each elytron with distinct but short impression and very small basal fovea located closer to humerus than to scutellum; humeral carina fine, as long as 1/6 of EL; apices of elytra separately rounded. Punctures on elytra much more distinct than those on head and pronotum, visible at magnification 40x, large but very shallow and with diffuse margins, separated by spaces similar to puncture diameter; setae similar to those on pronotum. Legs moderately long and slender; all tibiae straight.

Aedeagus ( Figs. 5, 6 ) in ventral view drop-shaped with narrow, subtriangular and blunt apex slightly curved ventrally in lateral view; AeL 0.11 mm. Endophallus lightly sclerotized and relatively simple; parameres slender, not exceeding apex of median lobe, with apices slightly broadened mesally at insertion of subapical seta; each paramere bearing two setae.

Female. Unknown.

Distribution. East Malaysia (Borneo: Sarawak).

Etymology. Locotypical, after the state Sarawak of Malaysia.

Remarks. This species is distinctly larger than L. sumatranus and L. sabahensis , and can be distinguished from both of them on the basis of a different shape and internal structures of the aedeagus.

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.