Scydmaenus (Geoscydmaenus) isaloensis Franz

Jałoszyński, Paweł, 2016, Review of Scydmaenus (Geoscydmaenus) of Madagascar (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4205 (3), pp. 265-274 : 268-271

Scydmaenus (Geoscydmaenus) isaloensis Franz

( Figs 1, 3–4 , 11 , 12, 14 , 16–18 , 22–23 )

Scydmaenus (Geoscydmaenus) isaloensis Franz, 1986: 372 , figs 339–341.

Type material. Holotype ( MADAGASCAR): ♂, two labels ( Fig. 1 ): "S-Madagaskar / Massif de l'Isalo / lg. H.Franz 1969" [white, printed] with " Mg 20" handwritten in blue on the reverse side; Scydmaenus / ( Geoscydmaenus ) / isaloensis m. / det. H.Franz " [white, handwritten and printed]; " ♂ " [white, printed]; " Typus " [red, handwritten] ( NHMW) . Paratypes: 12 exx., same data as for holotype ( NHMW) .

Additional material studied: 16 exx., Madagascar, Isalo N.P., Ananalava forest , 719-741 m, 17-18.i.2013, sifted leaf litter, L.S. Rahanitriniaina & E.M. Rabotoson leg. ; 2 exx., Madagascar, Isalo N.P., Piscine naturelle, 852 m, 21.i.2013, sifted leaf litter, L.S. Rahanitriniaina & E.M. Rabotoson leg. ; 2 exx., Madagascar, Isalo N.P., Oasis forest , 894 m, 20.i.2013, sifted leaf litter, L.S. Rahanitriniaina & E.M. Rabotoson leg. ( MMBC, cPJ).

Revised diagnosis. Head broadest near posterior margin of vertex, strongly narrowing anteriorly; profemur of male with clavate part strongly convex dorsally and ventrally, with long ventral projection located near middle, its apex hook-shaped; protibia of male abruptly broadened distally and slightly but distinctly curved; aedeagus with deeply notched apex, lateral apical lobes distinctly separated at middle.

Redescription. Body of male ( Fig. 3 ) strongly elongate and slender, strongly flattened, yellowish to light brown and covered with light brown setae; BL 0.76–0.83 mm (mean 0.80 mm).

Head ( Figs 3–4 ) in dorsal view subtriangular with weakly rounded sides, broadest shortly in front of occipital constriction and strongly narrowing anteriorly, HL 0.13–0.15 mm (mean 0.14 mm), HW 0.15–0.16 mm (mean 0.15 mm); vertex and frons confluent, evenly but weakly convex; supraantennal tubercles feebly marked. Dorsal surface of head covered with shallow but distinct and relatively large punctures distributed mostly on sides of vertex and frons, with much smaller punctures on median area ( Fig. 4 ), but the size of finely punctate region is variable and in some specimens large punctures occupy nearly entire frons and vertex; setae short and sparse, nearly recumbent. Antennae ( Fig. 12 ) short, AnL 0.33–0.35 mm (mean 0.34 mm); scape and pedicel strongly elongate, antennomeres III–V each distinctly elongate, VI about as long as broad, VII and VIII distinctly transverse, IX and X about as long as broad, XI about 1.6–1.7× as long as broad.

Pronotum in dorsal view ( Figs 3–4 ) oval, broadest between middle and anterior third; PL 0.21–0.23 mm (mean 0.22 mm), PW 0.20–0.23 mm (mean 0.21 mm). Punctures on pronotal disc shallow and diffused, inconspicuous; setae short, sparse and nearly recumbent.

Elytra ( Fig. 3 ) oval and strongly elongate, broadest near anterior third, EL 0.43–0.45 mm (mean 0.44 mm), EW 0.25–0.28 mm (mean 0.27 mm), EI 1.55–1.80. Elytra covered with distinct and dense punctures, which are small and with diffused margins; setae similar to those on pronotum.

Legs ( Figs 3 , 11 , 14 ) relatively short and robust; profemur ( Fig. 14 ) with large clavate part similarly strongly convex dorsally and ventrally, with ventral submedian projection bearing small apical denticle directed toward trochanter and long seta at base of projection ( Fig. 11 ); protibia ( Fig. 14 ) strongly and abruptly thickened slightly distally to middle, and slightly but distinctly curved.

Aedeagus ( Figs 16–18 , 22–23 ) elongate, AeL 0.20 mm; median lobe in ventral view with distinctly demarcated apical portion bearing a pair of lateral apical lobes separated at middle by deep notch.

Female. Similar to male, except for distinctly more slender profemora lacking ventral projections and nearly straight and only slightly, gradually thickened protibiae. BL 0.80–0.83 mm (mean 0.81 mm); HL 0.13–0.14 mm (mean 0.13 mm), HW 0.15–0.16 mm (mean 0.15 mm), AnL 0.35 mm; PL 0.20–0.21 mm (mean 0.21 mm), PW 0.18–0.19 mm (mean 0.18 mm); EL 0.43 mm, EW 0.25–0.26 mm (mean 0.26 mm), EI 1.62–1.70.

Distribution. Central-southern Madagascar, Ihorombe Region.

Figures

FIGURES 1 – 8. Scydmaenus (Geoscydmaenus) of Madagascar. Scydmaenus isaloensis Franz (1, 3 – 4) and Sc. madagassicus Franz (2, 5 – 8). Set of original labels of holotype (1 – 2); dorsal habitus of male (3); head and prothorax in dorsal (4 – 5) and ventral (6) views; head in ventral (7) and lateral (8) view. Abbreviations: bst, basisternal part of prosternum; fr, frons; gp, gular plate; hr, hypostomal ridge; hy, hypomeron; occ, occipital constriction; ptp, posterior tentorial pit; vt, vertex.

FIGURES 9 – 11. Scydmaenus (Geoscydmaenus) of Madagascar. Scydmaenus madagassicus Franz (9 – 10) and Sc. isaloensis Franz (11). Pterothorax and abdomen in ventral view (9); pterothorax, transparent mount in ventral view (10); profemoral ventral tooth of male in lateral view (11). Abbreviations: aest 3, metanepisternum; ar, anterior ridge; lf, lateral fovea; lmfa, lateral metafurcal arm; mscc, mesocoxal cavity; mscs, mesocoxal socket; msvp, mesoventral intercoxal process; mtvc, metaventral carina; mtvp, metaventral intercoxal process; pcr, procoxal rest; pre, prepectus.

FIGURES 12 – 15. Scydmaenus (Geoscydmaenus) of Madagascar. Scydmaenus isaloensis Franz (12, 14) and Sc. madagassicus Franz (13, 15). Right antenna of male in dorsal view (12 – 13); right fore leg of male in anterior view.

FIGURES 16 – 21. Scydmaenus (Geoscydmaenus) of Madagascar. Scydmaenus isaloensis Franz (16 – 18) and Sc. madagassicus Franz (19 – 21). Aedeagus in ventral (16, 19) and lateral (17 – 18, 20) view (with partly exserted flagellum in Fig. 18); spermatheca (21).

FIGURES 22 – 25. Scydmaenus (Geoscydmaenus) of Madagascar. Scydmaenus isaloensis Franz (22 – 23) and Sc. madagassicus Franz (24 – 25). Aedeagus in ventral (22, 24) and lateral (23, 25) views.