Scydmaenus (Geoscydmaenus) madagassicus Franz

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

Scydmaenus (Geoscydmaenus) madagassicus Franz

( Figs 2, 5–10 , 13, 15 , 19–21 , 24–25 )

Scydmaenus (Geoscydmaenus) madagassicus Franz, 1986: 374 , fig. 342.

Type material. Holotype ( MADAGASCAR): ♂, two labels (Fig.): "S-Madagaskar / Forêt de Sakahara / lg. H.Franz 1969" [white, printed] with " Mg 18" handwritten in blue on the reverse side; Scydmaenus / ( Geoscydmaenus ) / madagassicus m. / det. H.Franz " [white, handwritten and printed]; " ♂ " [white, printed]; " Typus " [red, handwritten] ( NHMW) . Paratypes: 23 exx., same data as for holotype ( NHMW) .

Revised diagnosis. Head broadest near posterior third of vertex, moderately narrowing anteriorly; profemur of male with clavate part strongly convex dorsally but weakly ventrally, with short and straight ventral projection located between proximal third and middle; protibia of male gradually broadened distally and nearly straight; aedeagus with indistinct median apical notch not separating lateral lobes.

Redescription. Male very similar to Sc. isaloensis , only differences and measurements are given below. BL 0.80–0.83 mm (mean 0.81 mm).

Head ( Figs 5–8 ) broadest near posterior third of vertex and weakly narrowing anteriorly, in most specimens large punctures covering nearly entire surface of frons and vertex, but often small median area remains almost impunctate; HL 0.13–0.14 mm (mean 0.13 mm), HW 0.15 mm; AnL 0.3 9–0.43 (mean 0.41 mm). Antenna ( Fig. 13 ) slightly longer in relation to body length than that of Sc. isaloensis , with distinctly elongate antennomere VI, slightly elongate antennomere IX and distinctly asymmetrical antennomeres VI–VIII.

Pronotum ( Fig. 5 ) of the same shape and proportions as that in Sc. isaloensis ; PL 0.20–0.21 mm (mean 0.21 mm), PW 0.18–0.20 mm (mean 0.19 mm).

Elytra as in Sc. isaloensis ; EL 0.48 mm, EW 0.28–0.30 mm (mean 0.28 mm), EI 1.58–1.73.

Legs ( Fig. 15 ) with profemur less thickened in distal third, its clavate part strongly convex dorsally but only weakly so ventrally; ventral femoral projection short, straight and perpendicular to the long axis of femur, not accompanied by long seta and with evenly rounded apex; protibia ( Fig. 15 ) weakly and gradually thickened, almost straight.

Aedeagus ( Figs 19–20 , 24–25 ) elongate, AeL 0.25 mm; median lobe in ventral view with indistinctly demarcated apical portion, apex with indistinct median notch not separating lateral lobes.

Female. Similar to male, except for distinctly more slender profemora lacking ventral projections. BL 0.79– 0.84 mm (mean 0.82 mm); HL 0.13–0.14 mm (mean 0.13 mm), HW 0.15–0.16 mm (mean 0.16 mm), AnL 0.38– 0.43 mm (mean 0.41 mm); PL 0.21–0.23 mm (mean 0.22 mm), PW 0.20 mm; EL 0.45–0.48 mm (mean 0.46 mm), EW 0.28–0.30 mm (mean 0.28 mm), EI 1.58–1.73.

Distribution. South-western Madagascar, Atsimo-Andrefana Region.

Remarks. Franz (1986) stated that Sc. madagassicus had the head more elongate than Sc. isaloensis ; the pronotum in relation to the head broader than that in Sc. isaloensis ; and the profemur of male lacking tooth.

Moreover, the aedeagus of this species was described as "völlig anders gebaut" ("entirely differently built"), but the aedeagus of Sc. isaloensis was illustrated only in the lateral view, whereas that of Sc. madagassicus only in the dorsal view, so it is not possible to see any fundamental differences (especially knowing that Franz frequently illustrated aedeagi in a rather schematic and inaccurate way). Examination of the type series of both species revealed that the head is equally long and broad in Sc. isaloensis and Sc. madagassicus ; the species do not differ in the width of pronotum in relation to the width of head; and males of both species have the ventral femoral tooth. Consequently, all external morphological characters used by Franz to define these species have been misinterpreted, and his illustrations of aedeagi cannot be used to find any differences. Useful differences in the shape of profemora and tibiae, in the shape of the head; in the punctures on frons and vertex; and in proportions and shapes of antennomeres, were found during the present study; also the aedeagi truly differ in the general shape, although not so much in internal endophallic structures. Clearly these are closely related, but easily identifiable species.

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.