Rhynchoclaviger Wasmann, 1891

Raveloson, Ricca, Andrianaharison, Fumiko, Rakotonirina, Jean Claude & Hlaváč, Peter, 2025, The Pselaphinae (Coleoptera: Staphylinidae) of Madagascar. X. Revision of the myrmecophilous clavigerine genera Rhynchoclaviger Wasmann, 1891 and Paussiger Wasmann, 1893, Zootaxa 5673 (3), pp. 399-410 : 401-402

Rhynchoclaviger Wasmann, 1891

( Figs 1 , 5–9 )

Rhynchoclaviger Wasmann, 1891: 4 . Types species: Rhynchoclaviger cremastogastris Wasmann , by monotypy.

Rhynchoclaviger Wasmann ; Wasmann 1893a: 111 (in key); Raffray 1908: 420 (in key); Raffray 1908: 422 (redescription, catalogue); Jeannel 1954: 295 (in key); Jeannel 1954: 304 (redescription); Jeannel 1960: 191 (in key); Jeannel 1960: 201; Newton & Chandler 1989: 66 (catalogue); Sabella, Viglianisi & Petralia 2012: 432 (catalogue).

Diagnosis. Head capsule about twice as long as wide, lacking frontal and vertexal foveae, temples non-dentate, parallel-sided; head capsule delimited from neck region by straight occipital carina; posterior tentorial pits confluent in deep median impression; antenna pentamerous, scape minuscule, pedicel cylindrical, slightly transverse; terminal antennomere longer than 1–3 combined; pronotum non-dentate on sides, shorter than head capsule, with median antebasal foveae; lacking longitudinal sulcus or carinae; metaventrite in anterior part, with sharp, triangular median carina posteriorly bearing bunch of golden setae; elytra glabrous, lacking antebasal foveae, lacking striae, with lateral carinae, posterior margin of elytron lacking trichomes but with few long setae; first paratergite lacking lateral protrusion; mesotibia modified in both sexes; aedeagus almost symmetrical, about 2.8 times as long as wide, distal lobe with two long setae.

Redescription. Body ( Fig. 1 ) more than twice as long as wide, more than 2.3 mm long; reddish-brown, shiny, head capsule and pronotum with rough surface, elytra and abdomen smooth.

Head capsule sub-rectangular, about twice as long as wide, widest at level of eyes; with rostral lateral carina; lacking frontal and vertexal foveae; clypeus partly visible on sides; rostrum at anterior margin triangular; eyes moderately prominent, situated at about midpoint along sides of head capsule; temples non-dentate, parallel-sided, slightly shorter than frontal rostrum; head capsule delimited from neck region by straight occipital carina, neck region almost entirely retracted into prothorax; gular plate with variable structure, lateral portions with rugose surface, median part smooth, posterior tentorial pits confluent in deep median impression; neck region ventrally demarcated by transverse carinae.

Antenna pentamerous, clearly longer than head capsule; scape minuscule, entirely hidden under rostrum; pedicel cylindrical, slightly transverse; antennomere 3 resembles mushroom of the genus Boletus , more than twice as long as pedicel; antennomere 4 pedunculate at base, about 1.6 times as long as wide; terminal antennomere longest, longer than 1–3 combined, slightly dilated from base, from middle to apex parallel-sided, its apex truncate, lacking concentric short setae.

Pronotum about as long as wide, non-dentate on sides, shorter than head capsule; lacking squamous setae; lateral margin slightly convergent posteriad, strongly convergent anteriad; with median antebasal foveae; lacking longitudinal sulcus or carinae.

Prosternum fused with hypomera, with median triangular, sharp elevation, procoxae contiguous. Mesoventrite distinctly shorter than metaventrite; mesocoxae narrowly separated, isthmus width about third of diameter of mesocoxal cavity; disc of metaventrite in anterior part convex, with sharp, triangular median carina bearing on its posterior part bunch of golden setae; metaventrite declining to posterior margin, lacking any projection; metacoxae widely separated by wide metaventral posterior process which is strongly concave in middle.

Elytra 1.4–1.5 times as wide as long, much shorter than abdomen, glabrous, lacking antebasal foveae, lacking striae, with lateral carinae; postero-lateral corner of elytron obliquely bevelled mesad, with minuscule projection; humeri rounded, with weakly-defined humeral protrusion, lacking spines; posterior margin of elytron lacking trichomes but with few long setae.

Abdomen with composite tergite convex, with wide impression in basal half; lacking keels, with two lateral small asetose foveae; first three visible paratergites well-developed along all length of composite tergite, narrow, first paratergite lacking lateral protrusion. First visible sternite (III) short, second (IV) with transversal impression and median longitudinal carina, long, longer than third visible sternite (V).

Legs short and stout, protibia ( Fig. 5 ) with short, sharp preapical spine; mesofemur with sharp, long, basal spine, mesotibia folded in middle, apical part moderately dentate ( Fig. 6 ).

Aedeagus ( Figs 8, 9 ) almost symmetrical, elongate, about 2.8 times as long as wide, moderately slender; basal bulb well-separated from distal lobe, distal lobe about 1.2 times as long as basal bulb, bearing two long setae; endophallus with some different sclerites; dorsal diaphragm elliptical.

Sexual dimorphism. Females larger, more than 2.60 mm long, with shorter antennae, antennomere 4 only about 1.25 times as long as wide; mesofemora simple, mesotibiae with obtuse, preapical protrusion ( Fig. 7 ).

Distribution. Madagascar.

Remarks. Rhynchoclaviger is similar in appearance to Paussiger , but can be readily separated by the combination of following characters: 1) pentamerous antennae (tetramerous in Paussiger ), 2) temples and pronotum on sides non-dentate (strongly dentate in Paussiger ), 3) posterior part of head capsule behind eyes lacking carinae (with various number of carinae in Paussiger ), 4) lateral abdominal foveae of composite tergite asetose (setose in Paussiger ) and 5) metaventrite with median carina with bunch of setae on its posterior part (glabrous, lacking bunch of setae in Paussiger ).

Figures

FIGURES 1–4. Habitus. 1. Rhynchoclaviger cremastogastris, female. 2. Paussiger perrieri, male. 3. Paussiger grandis, male. 4. Paussiger fisheri, male.

FIGURES 5–9. Rhynchoclaviger cremastogastris. 5. Male foreleg. 6. Female middle leg. 7. Male middle leg. 8. Aedeagus, dorsal view. 9. Aedeagus, lateral view. Paussiger fisheri. 10. Aedeagus, dorsal view. 11. Aedeagus, lateral view. Scale = 0.2 mm.