Cephennomicrus palawanicus, Jałoszyński, 2021

Jałoszyński, Paweł, 2021, Cephenniini of the Philippines. Part 5. Three new species of Cephennomicrus Reitter (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 4975 (3), pp. 592-598 : 593-594

Cephennomicrus palawanicus sp. n.

( Figs 1 , 4–5 , 10 )

Type material. Holotype: PHILIPPINES (Palawan): ♂, three labels: “(PHILIPPINES) / Puerto Princesa / Palawan / 7. IX. 1985 / K. Ishikawa ” [white, printed], “Tullgren sample / of leaf litter” [white, printed], “ CEPHENNOMICRUS / palawanicus m. / P. Jałoszyński, 2021 / HOLOTYPUS” [red, printed] ( EUMJ) . Paratypes: 2 ♀♀, same data as for holotype, except for yellow “PARATYPUS” labels ( EUMJ, cPJ) .

Diagnosis. Body moderately large, BL ~ 0.75 mm, stout and strongly convex, with basic vestiture composed of extremely short, barely discernible setae, and with several macrosetae on pronotum and sides of elytra; antennal club dimerous; punctures on head, pronotum and elytra inconspicuous; pronotum with two pairs of distinct antebasal pits, lacking transverse impression; aedeagus in ventral view elongate drop-shaped, broadest in sub-basal region and with truncate, subtrapezoidal apex; endophallus with elongate, paired sclerites forming median longitudinal group in distal half.

Description. Body of male ( Fig. 1 ) stout, strongly convex, uniformly light brown; macrosetae of the same color as cuticle, basic vestiture of extremely short setae barely discernible; BL 0.73 mm.

Head broadest at large, moderately strongly convex and coarsely faceted eyes, HL 0.10 mm, HW 0.20 mm; vertex and frons evenly, weakly convex; frontal glands not discernible. Punctures and setae on frons and vertex indiscernible under magnification 100 ×. Antennae slender, with sharply delimited, large dimerous club, AnL 0.30 mm; antennomeres 1–2 each elongate, 3–8 each about as long as broad, 9 slightly elongate, 10 slightly longer than 10 but much broader, 11 slightly elongate.

Pronotum subtrapezoidal, broadest near anterior third but indistinctly narrowing posterad; PL 0.23 mm, PW 0.30 mm; anterior margin weakly convex; lateral margins strongly rounded in anterior half, nearly straight in posterior half; posterior corners slightly obtuse-angled; posterior margin nearly straight. Pronotal base with two pairs of small but deep circular pits, inner pair not connected by groove, distance between inner pits distinctly wider than between inner and outer pit. Punctures on pronotum extremely fine, inconspicuous; three pairs of macrosetae present: one near each hind angle, one near middle of lateral margin, and one slightly in front of posterior pronotal margin, at the level of lateral corner of scutellar shield.

Elytra together oval, broadest distinctly in front of middle; EL 0.40 mm, EW 0.35 mm, EI 1.14; humeral calli and short, shallow basal impressions distinct; subhumeral lines lacking; sides of elytra strongly rounded; elytral apices separately rounded. Punctures similar to those on pronotum, inconspicuous; only one pair of macrosetae found, situated laterally, just behind each humeral callus (but other macrosetae may be broken off).

Hind wings long and functional.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 4–5 ) elongate drop-shaped; AeL 0.15 mm; median lobe in ventral view broadest in sub-basal third, gradually narrowing toward subtrapezoidal, truncate apex; diaphragm ventral, circular, situated in sub-basal region; in lateral view apical region of median lobe broad, with dorsal wall sinuate; endophallus with elongate paired sclerites in median region of distal half of median lobe; parameres slender and in lateral view nearly straight, each with two long apical setae.

Female. Externally indistinguishable from male. BL 0.73 mm; HL 0.10 mm, HW 0.18–0.19 mm, AnL 0.28–0.29 mm; PL 0.23 mm, PW 0.30 mm; EL 0.40 mm, EW 0.35–0.36 mm, EI 1.10–1.14.

Distribution. Central Palawan ( Fig. 10 ).

Etymology. Named after the island of Palawan.

Remarks. Among species known to occur in the Philippines, C. palawanicus can be unambiguously identified by the general shape of the median lobe and the unique, sclerotized endophallic structures. In species with a similar shape of the aedeagus (i.e., C. macrocephalus and C. leyteanus ), external morphological structures differ strongly from those in C. palawanicus . In C. macrocephalus , the body is larger, 1.13 mm in length, with the head conspicuously large in relation to the pronotum, and distinct, dense punctures on the pronotal disc. In C. leyteanus , the body is also larger, reaching 1.1 mm, and stouter, with sides of pronotum strongly convergent posterad, and with a trimerous antennal club.

Figures

FIGURE 10. Distribution of nominal Cephennomicrus species within the Philippines, with unique aedeagus illustrated for each species.

FIGURES 1–3. Dorsal habitus of holotype males. Cephennomicrus palawanicus sp. n. (1); C. impressus sp. n. (2); C. lagun- ensis sp. n. (3).

FIGURES 4–9.Aedeagus in ventral (4, 6, 8) and lateral (5, 7, 9) views. Cephennomicrus palawanicus sp. n. (4–5); C. impressus sp. n. (6–7); C. lagunensis sp. n. (8–9).