Semiclaviger Wasmann, 1893

Hlaváč, Peter, Baňař, Petr & Parker, Joseph, 2013, The Pselaphinae of Madagascar. II. Redescription of the genus Semiclaviger Wasmann, 1893 (Coleoptera: Staphylinidae: Pselaphinae: Clavigeritae) and synonymy of the subtribe Radamina Jeannel, 1954, Zootaxa 3736 (3), pp. 265-276 : 266-271

Semiclaviger Wasmann, 1893

Semiclaviger Wasmann, 1893a: 102 . Type species: Semiclaviger sikorae Wasmann , by monotypy Semiclaviger Wasmann : Jeannel, 1954: 331; Jeannel, 1960: 209

Diagnosis. Small-sized, stout and ovoid clavigerine with four-segmented antennae, scape and pedicel small, both completely hidden in antennal cavity, antennomere III weakly separated from IV which is of medium length, slightly curved and fastigiate to apex, with truncate and setose apex; head very short, strongly transverse, eyes strongly projecting laterad, bisected into two parts by ocular canthi. Occipital constriction and neck region absent dorsally but present ventrally, pronotum and elytra lacking foveae, with even lines of long setae, elytra, abdomen and first visible paratergites with trichomes; composite tergal plate (IV–VI) divided in three sectors by short, trichome-bearing keels.

Description. Body ( Figs. 1–3 ) limuloid, uniformly reddish-brown, entirely glabrous, shiny, with long, abristle setae on head, pronotum, elytra and paratergites. All body faces sparsely covered (studied in gold-plated specimens during SEM photographing) with minute granules, granules possibly of waxy origin ( Figs. 11–17 ). These granules were lost after NaOH treatment.

Head ( Figs. 4–9 ) short, transverse, partly retracted under pronotum, with short, wide, rounded rostrum, dorsally with no indication of occipital constriction or carina, neck region completely absent, posterior margin straight, eyes well-developed, strongly projecting laterad, bisected into two parts, clearly visible dorsally and ventrally, clypeus ( Figs. 4–5 , cl) with few short setae and with anterior margin rounded.

Mouth parts rudimentary but well-developed, completely hidden in buccal cavity ( Fig. 4 , bc) which is transverse, about three times as wide as high. Labrum ( Fig. 6 , lb) small. Maxilla ( Fig. 6 ) reduced, cardo ( Fig. 6 , cd) semi-spherical, basistipes ( Fig. 6 , bst) triangular, bearing one long seta, with one palpomere ( Fig. 6 , plp), expanded in middle, pointed at apex, with several long apical setae, mentum ( Fig. 6 , mn) rectangular, clearly wider than long, with many long setae.

Venter of head ( Figs. 5, 6 ) glabrous, with few setae and large punctures, mentum and submentum fused, lacking parallel carinae, genae oval, head divided by occipital constriction ( Fig. 5 , occ) into larger head capsule and short, smooth gular plate, pre-occipital constriction part with isodiametric sculpture, gular plate ( Fig. 5 , gp) with two largely separated tentorial pits ( Fig. 6 , tp).

Antennae ( Figs. 7 , 10 ) with four antennomeres, scape and pedicel minuscule, subequal in length, antennomere III slightly longer, weakly separated from antennomere IV, antenommeres I-III completely hidden in large antennal cavity, antennomere IV ( Fig. 10 ) clearly longest, cylindrical, slightly fastigiate apically, apex truncate, with dense setation.

Pronotum ( Fig. 11 ) strongly transverse, about twice as wide as long, evenly widened posteriorly, slightly shorter than elytra, lateral parts with isodiametric sculpture, whole lateral margin with long, thick setae, with large median, posterior lobe, lateral corners sharp, lacking foveae or carinae, scutellum not visible.

Venter ( Figs. 3 , 14 , 22 ) entirely glabrous. Prosternum ( Fig. 22 ) about three times shorter than pronotum, with basisternal part ( Fig. 22 , bs) short, demarcated from procoxal cavities ( Fig. 22 , pcc) by distinct carina, procoxal cavities separated in middle by fine prosternal carina ( Fig. 22 , psc), procoxal sockets ( Fig. 22 , pcs) open. Hypomera large, expanded mesally to sharp triangular projection. Mesonotum ( Fig. 23 ) subtriangular in shape, mesoscutum ( Fig. 23 , msc) transverse, with few lateral setae, mesoscutellum ( Fig. 23 , msl) subtriangular with pointed posterior margin. Mesoventrite about three times shorter than metaventrite, fused together, anterior mesoventral process subtriangular, mesocoxae well-separated, isthmus only slightly narrower than diameter of mesocoxae; metaventrite large, much wider than long, glabrous, on sides with sparse setae, with triangular median depression, metacoxae widely separated by wide, short, concave basal metaventral process ( Fig. 14 , mtvp). First visible sternite (III) about half as long as second (IV), second with two well-defined basolateral foveae ( Fig. 24 , blf), third (V) longest, about 1.5 times as long as second (IV), fourth (VI) shorter than second (IV), all sternites glabrous, sternite III-IV with long lateral setae, pygidium (Fig. 25, IX), small, ovoid.

Elytra ( Figs. 2 , 12 ) shiny, at suture about as long as abdomen and slightly longer than pronotum, with long setae arranged in even lines, humeri with sharp, slightly prominent angles, posterior elytral corners with short, sharp projections; lacking basal foveae and striae, each elytron with well-defined median trichome ( Fig. 13 ).

Abdomen ( Figs. 13, 15 ) shiny, glabrous, lacking setae, with pair of prebasal keels bearing trichomes that divide composite tergal plate (IV–VI) into three sectors, each sector with slight prebasal depression; tergites VII and VIII very short, not visible in dorsal view; paratergites IV–VI well-defined, large, with long setae on sides, paratergite IV on surface with dense, trichome like setation.

Legs short, femora clavate, ventral part of femora with deep channels for accomodation of tibiae, tibiae sticklike, about as long as femora, with long apical setae, mesotibiae with long and sharp preapical spur ( Fig. 20 ). Tarsi ( Figs. 18–21 ) 3-segmented, tarsomere I rudimentary, almost invisible, considerably shorter than II, tarsomere III very long, more than 5 times as long as II, tarsomeres I-II with long setae.

Aedeagus ( Figs. 26, 27 ) elongate, parameres completely fused to median lobe, apical lobe with four setae, not separated from basal bulb, dorsal diaphragm present, circular.

Sexual dimorphism. Female with simple mesotibiae, lacking long preapical spur.

Differential diagnosis: Semiclaviger is readily separated from all other genera of Clavigeritae by the ovoid, limuloid, compact shape of the body and by the eyes strongly projecting laterad and bisected into two parts.

Figures

FIGURE 1. Semiclaviger sikorae Wasmann, 1893, male, total dorsal view. Scale bar 1.0 mm.

FIGURES 2 – 7. Semiclaviger sikorae Wasmann, 1893. 2 – 3 male; 4 – 7 female. 2 — dorsal habitus; 3 — ventral habitus (III-IX — abdominal segments III-IX); 4 — head, anterior view (bc— bucal cavity, cl— clypeus, fr— frons); 5 — head, ventro-lateral view (cl— clypeus, gen— gena, gp— gular plate, occ— occipital constriction); 6 — trophi, antero-ventral view (bst— basistipes, cdcardo, lb— labrum, md— mandibula, mn— mentum, plp— palpomere, tp — tentorial pit); 7 — basis of antennae, anterior view (pd— pedicel, sc— scape).

FIGURES 8 – 15. Semiclaviger sikorae Wasmann, 1893. 8, 14 female; 9 – 13, 15 male. 8 — head, antero-dorsal view; 9 — dorsal face of head, dorso-lateral view; 10 — right antenna, dorsal view; 11 — head and pronotum, dorsal view; 12 — elytra, dorsal view; 13 — apex of left elytron with trichome, dorsal view; 14 — meso and metaventrite (cox II— mesocoxa, cox III — metacoxa, ististhmus, mtvp— metaventral process, tr II — mesotrochanter, tr III— metatrochanter); 15 — abdomen, dorsal view.

FIGURES 16 – 21. Semiclaviger sikorae Wasmann, 1893. 16 – 17, 21 female; 18 – 20 male. 16 — abdomen, ventral view; 17 — detail of surface of abdomen, ventral view; 18 — right fore tarsus, ventral view; 19 — basis of right fore tarsus, ventral view; 20 — right middle tibia, postero-dorsal view; 21 — right middle tarsus, anterior view.

FIGURES 22 – 24. Semiclaviger sikorae Wasmann, 1893, female. 22 — prosternum (bs— basisternal part, hy— hypomera, pccprocoxal cavity, pcs— procoxal socket, psc— prosternal carina); 23 — mesonotum (msc— mesoscutum, msl— mesoscutellum); 24 – abdomen, ventral view (blf— basolateral fovea, III-VI — sternites); 25 – terminalia, sternites VIII (VIII) and IX (IX) (pygidium) and tergite VIII (tg VIII). Scale bar in mm.

FIGURES 26 – 27. Semiclaviger sikorae Wasmann, 1893, male, aedeagus. 25 — dorsal view; 26 — lateral view. Scale bar in mm.