Orphnebius (Deroleptus) barsevskisi Shavrin, 2024

Shavrin, Alexey V. & Medina, Milton Norman D., 2024, Two new species of the genus Orphnebius Motschulsky, 1858 from Mindanao, Philippines (Coleoptera: Staphylinidae: Aleocharinae: Lomechusini), Zootaxa 5424 (4), pp. 483-489 : 484-486

Orphnebius (Deroleptus) barsevskisi Shavrin , sp. n.

( Figs 1–9 )

Type material. Holotype ♂ ( Fig. 1 ; dissected; right tibia and tarsus absent; basal part of the aedeagus deformed): ‘ Philippines, Mindanao, Maragu- | san, 700m, Marangig Falls, Can- | dalaga Mts., 7°2´N 126°10´E. 08- | 09.05.2023. Shavrin A. V. leg.’ <printed>, ‘sifting of wet litter and deb- | ris on slope near the river’ <printed>, ‘ HOLOTYPE | Orphnebius (Deroleptus) | poncei sp. n. | Shavrin A. V. des. 2024’ <red, printed> ( DUBC).

Description. Measurements: HW: 0.52; HL: 0.32; OL: 0.17; TL: 0.12; AL: 0.73; PL: 0.28; PW: 0.44; ESL: 0.32; EW: 0.70; MTbL: 0.30; MTrL: 0.32; AW: 0.67; AedL: 0.20; BL: 4.35.

Body and antennae yellowish, with slightly darker head and abdomen, and slightly paler elytra (antennomere 3 darker, two apical antennomeres slightly paler); mouthparts and legs yellow (basal part of tibiae slightly darker).

Head transverse, 1.6 times as broad as long, with widely rounded postocular portions and posterior margin widely truncate in the middle. Punctation distinct, moderately fine and sparse, larger between margins of eyes and middle portion; middle and posterior portions without punctures. Frontal and middle portions without microsculpture, but postocular and basal portions with fine transverse microreticulation. Lateral portions of clypeus strongly sclerotized. Eyes large and distinctly convex, reaching about posterior third of head in dorsal view. Temples long, 1.4 times as long as longitudinal length of eyes. Antenna reaching apical margin of elytra when reclined; antennomeres 4–10 slightly transverse; antennomere 4 indistinctly broader than antennomere 3, 5 slightly longer and indistinctly broader than 4, 6–8 slightly longer and broader than 5, 9–10 slightly longer than 8, apical antennomere about as long as two preceding segments, from widest basal portion gradually narrowed toward acute apex.

Pronotum small, distinctly narrower than head, transverse, 1.5 times as broad as long, from broadest anterior angles gradually narrowed posteriad toward widely rounded hind angles. Disc with fine and very sparse punctation, indistinct in middle and mediobasal portions. Microsculpture absent.

Elytra shortened, slightly longer than pronotum, transverse, distinctly more than twice as broad as long. Punctation very fine and moderately dense, indistinct in median and apical portions. Microsculpture distinct and dense, transverse in basal and isodiametric in middle and apical portions. Hind wings fully developed.

Legs very long and slender, with somewhat straight metatibia; metatarsus slightly longer than metatibia.

Abdomen distinctly narrower than elytra, with shiny tergites, without visible punctation and with fine transverse microreticulation on tergites III–V; abdominal tergites III–V with long postero-lateral processes; tergite IV distinctly longer than III; V significantly shorter than IV; VI very long, slightly shorter than previous two tergites.

Male. Abdominal tergite VII moderately short and narrow, with distinctly crenulate latero-apical margins ( Fig. 2 ); lateral margins of tergite VIII distinctly serrate, with three moderately large slightly projected rounded protrusions, starting slightly below middle and reaching about apical third ( Fig. 4 ). Abdominal sternite VII with dense and moderately fine punctation in middle ( Fig. 3 ). Abdominal sternite VIII as in Fig. 5 . Aedeagus elongate, moderately narrow, from apical third gradually narrowed toward small rounded apex ( Fig. 6 ). Lateral aspect of the aedeagus as in Fig. 7 . Paramere as in Fig. 8 .

Female unknown.

Comparative notes. Based on the general shape of the head with wide posterior portions and the general shape of the aedeagus, O. (D.) barsevskisi sp. n. is similar to O. (D.) tuberculifer Assing, 2021 and O. (D.) tuberosus Assing, 2021 , both recently described from Malaysia, North Borneo ( Assing 2021). It can be distinguished from O. (D.) tuberculifer by the broader apical portion of the pronotum and slightly narrower preapical part of the aedeagus, and from O. (D.) tuberosus by the distinctly narrower median lobe of the aedeagus. From both species it differs by the paler coloration of the distinctly larger body, longer eyes, the absence of tubercles on the dorsal surface of the abdominal tergite VIII and different structure of the internal sac. Based on the general shape of the forebody and the aedeagus, the presence of widely rounded posterior portions of head and the absence of tubercles on the dorsal surface of all apical abdominal tergites, O. (D.) barsevskisi sp. n. is also similar to O. (D.) poncei sp. n., from which it can be distinguished by the broader body, the paler elytra, slightly broader posterior portions of the head, the presence of microsculpture on the elytra, slightly broader median lobe and details of the structure of the internal sac. Besides that, it can be distinguished from O. (D.) bulbosus Assing, 2021 , recently described from Mindanao ( Assing 2021) by the slightly shorter body, paler coloration, longer and broader postocular portions of the head, broader apical portion of the pronotum, and significantly shorter preapical antennomere.

Distribution. The new species is known only from the type locality in Candalaga Mts., southern Mindanao ( Fig. 9 ).

Etymology. The new species is named in honour to our friend and colleague Prof. Dr. Arvids Barševskis (Daugavpils, Latvia), the rector of the Daugavpils University and well-known specialist of the beetle fauna of the Philippines.

Bionomics. The specimen was sifted from wet litter and debris on a slope near the river.

Figures

FIGURE 9. Distribution of Orphnebius in Mindanao: O. barsevskisi (circle), O. bulbosus (square), O. poncei (triangle).

FIGURES 1–8. Habitus of Orphnebius (s.str.) barsevskisi (holotype): 1—habitus, 2—male abdominal tergite VII, 3—male abdominal sternite VII, 4—male abdominal tergite VIII, 5—male abdominal sternite VIII, 6—aedeagus, ventral view, 7— aedeagus, lateral view, 8—paramere. Scale bars: 1.0 mm (Fig. 1), 0.1 mm (Figs. 2–8).