Clidicus occisor Jałoszyński, 2019

Jałoszyński, Paweł, Cheng, Zhi-Fei, Brajczewska, Nastazja & Yin, Zi-Wei, 2019, Hidden diversity of giant scydmaenines: five new species and new records of Clidicus in the Philippines (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4658 (3), pp. 571-584 : 578-580

Clidicus occisor Jałoszyński sp. n.

( Figs 21–26 )

Material studied. HOLOTYPE: ♂: PHILIPPINES, with three labels: “(PHILIPPINES) / Luan , alt. 50 m / S. Cotabato Prov. / Mindanao / 13. VIII. 1985 / K. Ishikawa leg.” [white, printed], “Tullgren sample / of leaf litter / in natural forest” [white, printed], “ Clidicus / occisor Jałoszyński / HOLOTYPUS ” [red, printed] ( EUMJ).

Diagnosis. Pronotum with evenly distributed, conspicuously deep and very dense punctures (distances between most punctures shorter than their diameters), lacking median impunctate line or area, cuticle between punctures finely shagreened and moderately glossy, pronotal disc with a sharply marked, narrow median longitudinal groove in posterior 1/4; aedeagus with symmetrical parameres, external margin of each broadly and deeply emarginate in subapical region, in lateral view parameres in subapical region not expanded dorsad.

Description. Body of male ( Fig. 21 ) elongate and slender, head flattened, prothorax and elytra strongly convex; legs and antennae long and slender, BL 5.25 mm; cuticle moderately glossy (more so on head), pigmentation uni- formly reddish brown, setae indistinctly lighter than cuticle.

Head ( Fig. 22 ) broadest slightly behind half of tempora, HL 0.90 mm, HW 1.25 mm; tempora in dorsal view 3 times as long as eyes, in anterior third straight and slightly divergent posterad, posteriorly strongly and evenly rounded; vertex with a deep subtrapezoidal posteromedian impression and a pair of posterior pits marking sites where dorsal tentorial arms are fused with dorsal wall of head. Sides of vertex convex, frons between antennal insertions nearly flat, entire frons and vertex with narrow median longitudinal groove, supraantennal tubercles small but distinctly elevated; compound eyes small, nearly round, strongly convex but in dorsal view not projecting from head silhouette, finely faceted. Punctures on sides of vertex and frons dense, distinct but shallow and with diffuse mar- gins, mesal margin of each eye and posterolateral margin of each supraantennal tubercle with an irregular group of dense punctures; supraantennal tubercles and posteromedian vertexal impression virtually impunctate. Setae long, sparse, suberect to erect. Antennae ( Fig. 23 ) slender, scape slightly longer than head, antennomeres II–VII elongate ( VII indistinctly so), VIII about as long as broad, IX slightly transverse, X distinctly transverse, XI about as long as broad; AnL 3.73 mm.

Labrum with straight anterior margin, lacking median notch.

Pronotum with subpentagonal disc and short posterior ‘collar’, broadest near anterior fourth; PL 1.28 mm, PW 1.23 mm; ‘collar’ demarcated by a narrow transverse groove with nine small pits; additionally two larger pits are present on each side of pronotum in its constricted portion; base with a well-marked median longitudinal groove at anterior margin of transverse antebasal groove, subequal to 1/4 of the length of pronotal disc. Punctures on disc distinct, much larger and deeper than those on head, almost evenly distributed, separated by spaces shorter than diameters of punctures, sides of pronotum (above each procoxal cavity) indistinctly punctate; setae moderately long, sparse, suberect. Cuticle between punctures on pronotal disc finely shagreened, less glossy than on head.

Elytra oval, broadest slightly in front of middle, EL 3.08 mm, EW 1.85 mm, EI 1.66; each elytron with five dorsal and one lateral rows of large and deep, densely distributed pits, cuticle between pits finely shagreened, less glossy than that on head, between rows with very fine and sparse setiferous punctures; setae longer and slightly thicker than those on head and pronotum, moderately dense, erect. Apex of each elytron obliquely truncated, with lateral corner rounded and indistinct, adsutural corner strongly projecting posterad, sharp-angled and pointed.

Hind wings absent.

Legs long and slender, unmodified.

Aedeagus ( Figs 24–25 ) strongly elongate but moderately slender, AeL 1.23 mm; parameres of equal length and shape, short, in ventral view lateral margin of each broadly and deeply emarginate in subapical region, apices distinctly divergent distad, rounded, in lateral view parameres in subapical region not expanded dorsad; flagellum differentiated from ductus ejaculatorius by a rapid broadening between proximal third and middle of median lobe. ‘Sperm pump’ ( Fig. 26 ) 0.68 mm in length, with two large ‘funnels’, distal funnel much shorter and slightly broader than proximal one.

Female. Unknown.

Distribution. Southern Mindanao.

Etymology. The Latin noun in apposition occisor means “a slayer, murderer”; refers to the typical of all Clidicus spp. evil-looking mandibles.

Remarks. This species is most similar to C. shavrini described below; they both have symmetrical parameres of a similar shape. However, the pronotum of C. occisor is more strongly punctate, the punctures are larger, deeper and denser than those in C. shavrini , and the longitudinal median groove is present (absent in C. shavrini ). The aedeagi, despite superficial similarity, clearly differ: in C. occisor the subapical lateral emargination of each paramere is much deeper and consequently the parameral apex is distinctly more slender than that in C. shavrini . Moreover, in lateral view, the parameres in C. occisor are not expanded dorsad, whereas in C. shavrini parameral apices form a rapid, rounded expansion. Also the aedeagus in lateral view is almost evenly curved in C. occisor , vs. rapidly bent in the proximal third in C. shavrini . The ‘sperm pump’ differs markedly between these two species; in C. occisor the proximal funnel is elongate and narrower than the transverse distal funnel, vs. both funnels strongly transverse and of equal diameters in C. shavrini .

Figures

FIGURES 21–26. Clidicus occisor Jałoszyński sp. n. Habitus of male (21); head of male in dorsal view (22), right antenna of male in dorsal view (23); aedeagus in ventral (24) and lateral (25) views; ‘sperm pump’ (26).