Clidicus asymmetricus, Jałoszyński, 2018

Jałoszyński, Paweł, 2018, A new species of Clidicus with asymmetrical parameres (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4399 (1), pp. 141-145 : 141-145

Clidicus asymmetricus sp. n. ( Figs 1 –11 )

Material studied. Holotype: male (PHILIPPINES, MINDANAO): three labels: "PHILIPPINES / 07°39'N 124°42'E / Mindanao, prov. Lanao de Sul / Wao / V 2017 / leg. Ismael Lumawig(local coll.)" [white, printed], "5960 / 156526 / coll. Upper Silesian Museum / (USMB) Bytom, Poland" [white, printed] " Clidicus / asymmetricus m. / P. JAŁOSZYŃSKI, 2018 / HOLOTYPUS" [red, printed] (USMB).

Diagnosis. Each of antennomeres II–XI distinctly elongate; anterior margin of labrum with three shallow and broad subtriangular emarginations; head slightly narrower than pronotum; tempora evenly rounded; aedeagus very slender and in lateral view strongly curved, one paramere much longer than the other and with its apical region strongly flattened laterally, in lateral view parameral apex broadened and curved ventrad; 'funnels' of 'sperm pump' equal in diameter, each very shallow and very broad.

Description. Body of male ( Fig. 1 ) elongate and slender, head flattened, prothorax and elytra strongly convex; legs and antennae long and slender, BL 6.05 mm; cuticle moderately glossy, pigmentation uniformly brown, setae slightly lighter than cuticle.

Head ( Figs 3–4 ) broadest shortly behind eyes, HL 0.98 mm, HW 1.40 mm; tempora in dorsal view ( Fig. 4 ) more than 4 times as long as eyes and evenly, strongly rounded; vertex with deep posteromedian impression and well-visible pits marking the sites where dorsal tentorial arms are fused with the head wall, sides of vertex convex; frons between antennal insertions slightly impressed, both frons and vertex with narrow median longitudinal groove, which is more pronounced posteriorly; supraantennal tubercles small but distinctly elevated; composite eyes small, nearly round, not projecting laterally from the head silhouette and relatively finely faceted. Punctures on vertex and frons distinct but shallow, except for supraantennal tubercles which are virtually impunctate, also median impression on vertex and median line on frons and vertex bear indistinct punctures; setae moderately long, sparse, suberect. Antennae ( Fig. 1 ) slender, all antennomeres elongate, scape slightly longer than head, AnL 4.18 mm.

Pronotum ( Fig. 3 ) with nearly round disc and short posterior 'collar', broadest near anterior third; PL 1.58 mm, PW 1.48 mm; 'collar' demarcated by narrow transverse groove with ten irregular and diffuse pits; additionally two larger pits are present on each side of pronotum in its constricted portion. Punctures on disc distinct but relatively small, shallow and diffuse, sides of pronotum (above each procoxal cavity) nearly impunctate; setae moderately long, sparse, suberect.

Elytra oval, broadest clearly in front of middle, EL 3.50 mm, EW 1.98 mm, EI 1.77; each elytron with five dorsal and one lateral rows of large and deep pits, cuticle between rows with very fine and sparse setiferous punctures; setae moderately long, denser than those on head and pronotum, suberect.

Hind wings absent.

Legs long and slender, unmodified.

Aedeagus ( Figs 7–10 ) strongly elongate, slender, AeL 2.33 mm; parameres of unequal length, the short one truncated at apex, the long one with broadened apical region, which is curved ventrad; flagellum not differentiated from ductus ejaculatorius, not broadened and straight. 'Sperm pump' ( Fig. 11 ) 0.65 mm in length (measured between lateral edges of 'funnels') with large 'funnels' equal in diameter.

Female. Unknown.

Distribution. Central Mindanao.

Etymology. The name refers to the asymmetrical aedeagus.

Remarks. Clidicus asymmetricus has a strikingly slender aedeagus with strongly asymmetrical parameres; this structure alone can be used to identify the species. Strongly asymmetrical parameres can also be found in C. minutus Orousset, 2014 (aedeagus very stout, 'sperm pump' extremely elongate and lacking 'funnels'), C. armipes Orousset, 2014 (aedeagus moderately stout, protibiae with two large ventral preapical teeth), and C. dohertyi Orousset, 2014 (aedeagus very stout with conspicuous subtriangular lateral projections, 'sperm pump' with 'funnels' of unequal length). Externally, it is most similar to the sympatric C. crocodylus Jałoszyński, 2009 . The latter species has adults showing a variable form of elytra; in males the elytra can be nearly parallel-sided (as illustrated for the holotype in Jałoszyński (2009), fig. 7) to more rounded at sides, resembling those of females (an example of such a stout male is shown in Fig. 2 ). Independently of the variation in the elytral shape, C. crocodylus has the antennae shorter in relation to the body length than those in C.

asymmetricus , the antennomeres being clearly more elongate in the latter species ( Fig. 1 vs. 2). The head in C. asymmetricus ( Figs 3–4 ) is broadest shortly behind the eyes, slightly narrower than pronotum and with evenly rounded tempora, whereas the head in C. crocodylus ( Figs 5–6 ) is broadest more posteriorly, slightly broader than pronotum and more triangular, with tempora behind eyes nearly straight and then rapidly curved mesad. Also the shape of pronotum slightly differs in these species; that in C. asymmetricus ( Fig. 3 ) has a longer posterior 'collar' with its sides slightly divergent caudad, whereas in C. crocodylus the short collar has its lateral margins parallel or slightly convergent caudad. The latter species has distinctly narrower 'funnels' of the 'sperm pump', a broadening of the ductus ejaculatorius that presumably can contract by means of longitudinal muscles fibers connecting sclerotized funnel-like ends of the 'pump'; its function remains unknown, the term 'sperm pump' was in use since Besuchet (1971).

Figures

FIGURES1–2.Clidicus of the Philippines,dorsal habitus of males.Clidicus asymmetricus sp.n. (1); C.crocodylus Jałoszyński (2).

FIGURES3–6. Clidicus ofthe Philippines,pronotum and head of males (pronotumin dorsalview,head slightly tilted ventrad) (3, 5), andhead indorsal view(4, 6).Clidicus asymmetricus sp.n.(3–4); C. crocodylus Jałoszyński (5–6).

FIGURES7–11. Clidicus asymmetricus sp.n.Aedeagus inventral (7–8) andlateral (9–10) views, and'spermpump' (11).