Micrillus intermedius (CAMERON 1936) Assing, 2013

Assing, V., 2013, On the Palaearctic and Oriental species of Scymbalium and Micrillus (Coleoptera: Staphylinidae: Paederinae), Linzer biologische Beiträge 45 (2), pp. 1479-1520 : 1499-1502

Micrillus intermedius (CAMERON 1936) , nov.comb.

( Figs 23-28 , Map 3 )

Scimbalium intermedium CAMERON 1936a: 43 .

Type material examined Lectotype, present designation: "Malaya Kuala Lumpur / M.Cameron. Bequest. B.M. 1955-147. Syntype / Lectotypus Scymbalium intermedium Cameron, desig. V. Assing 2013 / Micrillus intermedius (Cameron) , det. V. Assing 2013" (BMNH) . Paralectotypes: 4: same data as lectotype ( BMNH) ; 1: " Scimbalium intermedium Cam . Type / Ex F.M.S. Museum. B.M.1955-354 / Syntype" ( BMNH); 1: " Malaya, Kuala Lumpur / Scimbalium intermedium Cam / co-type / Coll. W. Champman in Coll. P. Griveau" ( MHNG) .

Additional material examined: Laos: 14exs., Udomxaiprovince, Pak Beng , 19°54'N, 101°08'E, 450 m, 18.-27.V.2001, leg. Kolibáþ ( NHMB, cAss) ; 35 exs., Vientiane province, Vang-Vieng, 18°55'N, 102°27'E, 300 m, 10.-15.V. & 1.-6.VI.2001, leg. Kolibáþ ( NHMB, cAss). Thailand: 1 ex., Chiang Mai province, Thaton , 20°04'N, 99°22'E, 450 m, riverside, at light, 22.VII.2006, leg. Mendel & Barclay (cAss) ; 4, 2, Bangkok ( BMNH, cAss) ; 1, " Siam " ( BMNH). Locality not identified: 5 exs., "F. [T? J?] Mo. S." ( BMNH) .

Comment: The original description is based on an unspecified number of syntypes from " Selangor: Kuala Lumpur " ( CAMERON 1936a). The male syntype from the Cameron collection at the BMNH is designated as the lectotype.

Redescription: Body length 4.2-5.0 mm; length of forebody 2.3-2.6 mm. Habitus as in Fig. 23 . Coloration: body pale reddish, with the head brown to blackishbrown; legs and antennae dark-yellow.

Head ( Fig. 24 ) approximately 1.05 times as long as broad, convex in cross-section, and with weakly marked posterior angles; dorsal surface with sparse punctation and with shallow, but distinct transverse microsculpture; eyes approximately 0.7 times as long as distance from posterior margin of eye to neck. Antenna approximately 1.8 mm long and slender, preapical antennomeres noticeably oblong.

Pronotum ( Fig. 24 ) approximately 1.2 times as long as broad and 1.05 times as broad as head, distinctly tapering posteriorly, and flattened, i.e., weakly convex in cross-section; dorsal surface with fine micropunctation, without appreciable macropunctation.

Elytra ( Fig. 24 ) 0.95 times as long as pronotum; punctation very dense and fine. Hind wings fully developed.

Abdomen with rather dense and fine punctation; interstices with shallow microsculpture.

: tergite VIII distinctly oblong and with strongly convex posterior margin; sternite VIII ( Fig. 25 ) approximately 1.3 times as long as broad, posterior excision deep and narrow, its depth approximately 0.4 times the length of sternite; aedeagus ( Figs 26-28 ) 0.45-0.50 mm long, distinctly asymmetric in ventral view; ventral process laterally compressed, furnished with numerous short marginal setae; dorsally with strongly apical sclerotized structure (modified dorsal plate?) of distinctive shape; internal sac with large and curved sclerotized structure, this structure apically with finger-shaped processes.

Comparative notes: In size, coloration, and other external characters, M. intermedius is similar to M. nigriceps , but distinguished by the male sexual characters. Its closest relative is M. sutteri (see the following section).

Distribution: Micrillus intermedius is currently known from Malaysia, Thailand (new record), and Laos (new record) ( Map 3 ).

Figures

Map 3: Distributions of Micrillus indicus (EPPELSHEIM) (triangles), M. nigriceps (CAMERON) (diamonds), M. intermedius (CAMERON) (open and filled circles), and M. siamensis nov.sp. (filled circle) in the Oriental region, based on examined records.

Figs 23-28: Micrillus intermedius (CAMERON): (23) habitus; (24) forebody; (25) male sternite VIII; (26) aedeagus in lateral view; (27) aedeagus in ventral view; (28) internal structure of aedeagus in lateral view. Scale bars: 23-24: 1.0 mm; 25-28: 0.2 mm.