Panscopaeus cameroni ( SCHEERPELTZ , 1933) Assing, Volker, 2011

Assing, Volker, 2011, A revision of Panscopaeus (Coleoptera: Staphylinidae: Paederinae), Beiträge Zur Entomologie = Contributions to Entomology 61 (2), pp. 389-411 : 407-409

Panscopaeus cameroni ( SCHEERPELTZ, 1933) , comb. n. ( Figs 61-67 )

Medon lithocharoides CAMERON, 1924b: 313 f.

Medon cameroni SCHEERPELTZ, 1933: 1260 ; replacement name.

Type material examined:

Syntype ♀: "Sumatra, Fort de Kock , VIII.94, E. Modigliani / Museo Civ. Genova / Medon lithocharoides Cam / M. Cameron Bequest, B.M.1955-147 / Syntype / Syntypus ♀ Medon lithocharoides Cameron , rev. V. Assing 2010 / Panscopaeus cameroni (Scheerpeltz) , det. V. Assing 2010" ( BMNH) .

Additional material examined:

Sumatra: 2 exs., Fort de Kock , 920 m, 1925, leg. Jacobson ( FMNH) ; 1 ♂, 2 ♀ ♀, Brastagi , 6.VI.1984, leg. Rougemont (cRou, cAss) . Bali : 1 ♀, Gunung [= Mount] Agung, 10.VII.1982, leg. Rougemont (cRou).

Comment:

Medon lithocharoides was described from an unspecified number of female syntypes (" ♂: unknown") from "Sumatra: Fort de Kock, August 1894 (Dr. E. Modigliani)" ( CAMERON 1924b). The name is a junior secondary homonym of Panscopaeus lithocharoides ( SHARP, 1874) and Stilicus lithocharoides CAMERON, 1924 , and was subsequently replaced with the nomen novum M. cameroni by SCHEERPELTZ (1933). One of the syntypes, a female, was located in the Cameron collection at the BMNH. Whether or not the syntypes are indeed all females remains unclear. Due to the absence of a median excision at the posterior margin of the male sternite VIII, males may easily be mistaken for females.

Redescription:

Body length 4.3-4.7 mm. Coloration: head dark-brown; pronotum reddish-brown to castaneous; elytra reddish to brown; abdomen brown, with the posterior margins of the segments and the apex reddish; legs yellowish-brown; antennae reddish.

Head ( Fig. 61 ) 1.10-1.15 times as wide as long; posterior margin distinctly concave; postocular region weakly convex in dorsal view; posterior angles marked; neck approximately 0.2 times the width of head in dorsal view; punctation of dorsal surface very fine and moderately dense in lateral portions, sparser in median dorsal portion; interstices in median dorsal portion without distinct microsculpture and glossy ( Fig. 62 ). Eyes large and bulging, as long as, or slightly longer than postocular region in dorsal view. Antenna similar to that of P. yakushimanus .

Pronotum ( Fig. 61 ) moderately transverse, approximately 1.1 times as wide as long and nearly 0.95 times as wide as head, widest at anterior angles; punctation fine and extremely dense; interstices without distinct microsculpture; midline narrowly impunctate and glossy ( Fig. 63 ).

Elytra ( Fig. 61 ) approximately 1.1 times as long and 1.3 times as wide as pronotum; punctation very dense and less fine than that of head and pronotum; interstices narrower than diameter of punctures and without distinct microsculpture. Hind wings fully developed. Metatarsomere I distinctly longer than II.

Abdomen narrower than elytra; punctation very fine and dense; interstices on anterior tergites glossy, on posterior tergites with shallow microsculpture; posterior margin of tergite VII with palisade fringe.

♂: sternite VII unmodified; posterior margin of sternite VIII broadly produced, without median excision ( Fig. 64 ); aedeagus ( Figs 65-67 ) approximately 0.6 mm long; dorsal plate short and with lamellate basal portion; apical internal structures of distinctive shape; ventral process somewhat asymmetric, apically neither bifid nor concave in ventral view.

Comparative notes:

Panscopaeus cameroni is distinguished from all its congeners particularly by the absence of microsculpture in the median dorsal portion of the head and on the pronotum, the extremely dense punctation of the pronotum, the highly distinctive shape of the male sternite VIII (posteriorly produced and without median excision), as well as by the morphology of the aedeagus.

Distribution and natural history:

Confirmed records of this species have become known only from Sumatra and Bali.

Figures

Figs 61-67: Panscopaeus cameroni: forebody (61); median dorsal portion of head (62); median portion of pronotum (63); male sternite VIII (64); aedeagus in lateral view (65); aedeagus in ventral view (66); apical portion of aedeagus in ventral view (67). Scale bars: 61: 0.5 mm; 64-66: 0.2 mm; 62-63, 67: 0.1 mm.