Cephennomicrus lagunensis, 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 : 596-597

Cephennomicrus lagunensis sp. n.

( Figs 3 , 8–9 , 10 )

Type material. Holotype: PHILIPPINES ( Luzon ): ♂, three labels: “(PHILIPPINES) / Mt. Maquiling / alt. 400 m / Laguna Prov. / Luzon, 12. IX. / 1985, K. Ishikawa ” [white, printed], “Tullgren sample / of fallen fruit / of Ficus sp.” [white, printed], “ CEPHENNOMICRUS / lagunensis m. / P. Jałoszyński, 2021 / HOLOTYPUS ” [red, printed] ( EUMJ).

Diagnosis. Body large, nearly 1 mm in length, moderately stout and strongly convex, with basic vestiture composed of extremely short, barely discernible setae, and with macrosetae on pronotum and sides of elytra; antennal club dimerous; punctures on head, pronotum and elytra inconspicuous; pronotum with two pairs of antebasal pits, inner pair not connected by transverse impression; aedeagus conspicuously long, in ventral view with elongate and oval basal capsule and extremely long and narrow apical projection, diaphragm situated on base of median lobe, endophallus with looped flagellum.

Description. Body of male ( Fig. 3 ) moderately stout, strongly convex, uniformly light brown; macrosetae of the same color as cuticle, basic vestiture of extremely short setae barely discernible; BL 0.95 mm.

Head broadest at large, moderately strongly convex and coarsely faceted eyes, HL 0.13 mm, HW 0.26 mm; vertex and frons evenly, weakly convex; frontal glands not discernible. Punctures and setae on frons and vertex inconspicuous. Antennae slender, with sharply delimited, large dimerous club, AnL 0.43 mm; antennomeres 1–2 each elongate, 3–9 each about as long as broad, 10 weakly transverse, 11 slightly elongate.

Pronotum subtrapezoidal with parallel sides in posterior 2/3; PL 0.28 mm, PW 0.36 mm; anterior margin weakly convex; lateral margins strongly rounded in anterior third, straight in slightly more than posterior half; posterior corners nearly right-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 much 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 between middle and anterior third; EL 0.55 mm, EW 0.45 mm, EI 1.22; 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; side of each elytron with four macrosetae, situated just behind humeral callus, near broadest site, slightly behind middle and in posterior 1/5.

Hind wings long and functional.

Legs moderately long and slender, unmodified.

Aedeagus ( Figs 8–9 ) extremely long; AeL 0.48 mm; median lobe in ventral view with elongate, oval basal capsule and long, slender apical projection with subtriangular, rounded apex, in lateral view basal capsule distinctly demarcated from apical projection, apex straight; endophallus with looped flagellum; parameres extremely long and slender, in lateral view nearly straight, each with two short apical and one similarly short subapical seta.

Female. Unknown.

Distribution. Southern Luzon ( Fig. 10 ).

Etymology. After Laguna Province of the Philippines.

Remarks. This externally unremarkable species, almost identical with many congeners that inhabit SE and NE Asia, has the most unusual, conspicuous aedeagus of all hitherto known members of Cephennomicrus . The proximal, capsular portion of the median lobe does not differ from similarly shaped aedeagi of many other species, except that the diaphragm is shifted to the base (in other species on the ventral wall). Its distal region, however, forms an extremely long apical projection, much narrower and longer than the basal capsule. The parameres are also enormously elongate, much longer than the capsular region. Distal projections in other species of Cephennomicrus are either as long as a tiny fraction of the basal capsule, or entirely lacking. Moreover, the aedeagus of C. lagunensis is half as long as the entire body (longer, considering that the body length was measured as HL + PL + EL, while the head is permanently strongly declined and the frons and vertex are almost perpendicular to the long body axis). In the dissected specimen, the tip of the aedeagus was projecting out of the abdomen, and the base of the median lobe was overlapping with the posterior margin of the metaventrite. Although large aedeagi among Cephenniini are not uncommon, the length of the median lobe exceeding length of the abdomen is an exceptionally rare phenomenon, previously known only in Mastigitae ( Jałoszyński et al. 2015).

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).