Cephennomicrus crypticus, Jałoszyński, 2025

Jałoszyński, Paweł, 2025, A new species and new records of Cephennomicrus Reitter on the island of Okinawa (Coleoptera, Staphylinidae, Scydmaeninae), Zootaxa 5620 (3), pp. 493-500 : 494-496

Cephennomicrus crypticus sp. n.

( Figs 1 , 7–10 )

Type material. Holotype: JAPAN (Okinawa Is.): ♂, two labels: “ JAPAN, OKINAWA Pref. / OKINAWA-jima, 31 xii 2024 / Ogimi, Nekumachiji-dake / 26.684151, 128.136069 / leg. P. JAŁOSZYŃSKI ” [white, printed], “ CEPHENNOMICRUS / crypticus m. / P. Jałoszyński, 2025 / HOLOTYPUS” [red, printed] ( NSMT).

Diagnosis. Member of Cephennomicrus taiwanensis species group (based on strongly elongate aedeagus with a long and broad endophallic tubular median duct flanked by a pair of elongate lateral structures forming central complex), with conspicuously strong and dense punctures on pronotal disc; endophallic tubular structure in ventral view forming one large median loop.

Description. Body of male ( Fig. 1 ) strongly convex, light brown; setae distinctly lighter than cuticle; BL 0.95 mm.

Head broadest across large, strongly convex and coarsely faceted eyes, HL 0.13 mm, HW 0.25 mm; frontal glands visible as a pair of tiny tubercles, each near mesal margin of eye; frontal region flattened, posteriorly confluent with convex vertexal region; supraantennal tubercles distinct but weakly elevated. Punctures on frons and vertex inconspicuous, fine; setae sparse, extremely short and suberect. Antennae slender, with broad dimerous clubs, AnL 0.40 mm; antennomeres 1 and 2 each slightly elongate, 3 slightly transverse, 4–6 each about as long as broad, 7 indistinctly elongate, 8 about as long as broad, 9 slightly elongate, 10 strongly transverse, 11 about as long as broad and distinctly longer than 10.

Pronotum subrectangular with convex anterior margin, broadest near anterior third; PL 0.30 mm, PW 0.38 mm; anterior margin arcuate; lateral margins strongly rounded in anterior half, nearly straight in posterior half; hind corners slightly obtuse and blunt; posterior margin indistinctly bisinuate. Pronotal disc with slightly microserrate lateral carinae and two pairs of small but distinct lateral antebasal pits. Punctures on pronotal disc strong and dense, separated by spaces subequal to or slightly narrower than diameters of punctures; setae short, dense and weakly suberect.

Elytra together oval, broadest distinctly anterior to middle; EL 0.53 mm, EW 0.45 mm, EI 1.17; humeral calli distinct; subhumeral lines lacking; sides of elytra strongly rounded; elytral apices separately rounded. Punctures fine and inconspicuous; setae similar to those on pronotum.

Hind wings long and functional.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 7–10 ) strongly elongate; AeL 0.28 mm; median lobe in ventral view broadest in basal region, with subtriangular apex; endophallus with long median tubular structure forming large median loop, distally flanked by a pair of strongly elongate dark sclerites. Parameres slender, their apices not reaching apex of median lobe, each paramere with one apical seta.

Female. Unknown.

Distribution. Northern area of Okinawa Island.

Etymology. The adjective crypticus refers to rather unremarkable external features that make this species difficult to distinguish from a more common C. nagoanus .

Remarks. Adults of this species are externally most similar to C. nagoanus ; they can be distinguished by a much stronger and denser punctures on the pronotal disc and a slightly narrower pronotum in relation to elytra. The long and medially looped tubular structure in the endophallus of C. crypticus is unique and allows for unambiguous identification.Among congeners that belong to the C. taiwanensis group, no other species has the tubular endophallic structure shaped like the one in C. crypticus ; if it forms a loop (in four other species), its placement and/or shape are clearly different (see Jałoszyński, 2009b: figs 21–32).

The six nominal species of Cephennomicrus that occur on Okinawa-jima can be identified using the following key:

1 Pronotum with median longitudinal groove; antennae with slender, weakly delimited trimerous clubs ( Figs 3, 6 )......... 2

- Pronotum lacking median longitudinal groove; antennae with broad, sharply delimited dimerous clubs ( Figs 1, 2, 4, 5 ).... 3

2 Body dark brown, nearly black ( Fig. 6 ); aedeagus with rapidly narrowed distal region ( Fig. 16 ); endophallic sclerites forming two small lateral groups and long median pair ( Fig. 17 )............................................ C. tenebrosus

- Body moderately dark brown ( Fig. 3 ); aedeagus drop-shaped, with gradually narrowed distal region ( Fig. 12 ); endophallus with only one median pair of long sclerites ( Fig. 12 )................................................... C. disjunctus

3 Pronotal punctures much more distinct than those on elytra ( Figs 1, 4 )........................................... 4

- Pronotal punctures as inconspicuous as those on elytra ( Figs 2, 5 ).............................................. 5

4 Pronotum distinctly narrower than elytra, covered with deep and dense punctures ( Fig. 1 ); endophallus with median tubular structure forming large median loop ( Fig. 7 )...................................................... C. crypticus

- Pronotum indistinctly narrower than elytra, covered with shallow and sparser punctures ( Fig. 4 ); endophallus with straight median tubular structure, lacking median loop ( Figs 13–15 )......................................... C. nagoanus

5 Body length <0.7 mm; setae on pronotum and elytra extremely short, barely discernible ( Fig. 2 ); aedeagus in ventral view elongate oval with median endophallic tubular structure ( Fig. 11 )........................................... C. aji

- Body length> 0.9 mm; setae on pronotum and elytra well-visible ( Fig. 5 ); aedeagus in ventral view subtriangular with asymmetrical apex and lacking median endophallic tubular structure ( Fig. 16 )......................... C. okinawanus

Figures

FIGURES 1–6. Dorsal habitus of Cephennomicrus spp. of Okinawa-jima, males. Cephennomicrus crypticus (1), C. aji (2), C. disjunctus (3), C. nagoanus (4), C. okinawanus (5), and C. tenebrosus (6).

FIGURES 7–17. Aedeagus in ventral (7, 9, 11–17) and lateral (8, 10) views. Cephennomicrus crypticus (7–10), C. aji (11), C. disjunctus (12), C. nagoanus (13–15), C. okinawanus (16), and C. tenebrosus (17).