Orphnebius species, MOTSCHULSKY, 1858

Assing, Volker, 2016, On some Lomechusini of the Palaearctic and Oriental regions (Coleoptera: Staphylinidae: Aleocharinae), Beiträge Zur Entomologie = Contributions to Entomology 66 (1), pp. 13-111 : 19-21

publication ID	https://doi.org/ 10.21248/contrib.entomol.66.1.13-111
DOI	https://doi.org/10.5281/zenodo.5879074
persistent identifier	https://treatment.plazi.org/id/766F7C36-FFB7-FFE3-FF68-75D6DDEDFBF8
treatment provided by	Felipe
scientific name	Orphnebius species
status

Treatment

3.1.2. Key to the named Orphnebius species of Laos

Since as many as 20 Orphnebius species are described from Laos, a country from where the genus had not been reported before, a key to species is provided.

1. Abdominal tergites IX and X strongly modified, with conspicuously dense and long pubescence; hemi-tergites IX strongly elongated in female, ventrally connected by thin sclerotized clasp-shaped structure, antero-ventrally with thin sclerotized projections in male. Posterior margin of tergite VIII mostly smooth, rarely coarsely serrate. Median lobe of aedeagus large in relation to body and with bulbous capsule (exception: O. reductus View in CoL ); paramere of more or less distinctly derived shape. Body in nearly all species distinctly bicoloured, with the forebody dark-brown to black (in one species only head blackish-brown and the remainder of the body reddish) and the abdomen reddish (occasionally with segment VIII infuscate). Antennae often more or less distinctly asymmetric. Sternites and paratergites III–V without distinct postero-lateral processes. Orphnebius hauseri View in CoL group. ....................................... 2

– Abdominal tergites IX and X not distinctly modified, short and without conspicuously dense pubescence, not distinctly elongated in female. Posterior margin of tergite VIII finely serrate or with two to three more or less pronounced tooth-like projections (in one species with additional short teeth). Median lobe of aedeagus small in relation to body, usually more or less dorso-ventrally depressed, with blade-shaped ventral process, and without sclerotized internal structures; paramere not distinctly modified. Body in most species of different coloration. Antennae symmetric. Sternites and paratergites III–V often with conspicuous postero-lateral processes. Deroleptus . .................................................................................................................................................................. 15

2. Head blackish-brown, distinctly contrasting with the reddish pronotum, elytra, and abdomen ( Fig. 45 View Figs 40–53 ). Antennae uniformly reddish ( Fig. 12 View Figs 1–26 ). Eyes large, occupying all of lateral margins of head ( Fig. 45 View Figs 40–53 ). Median lobe of aedeagus with very acute ventral process ( Figs 279–280 View Figs 277–295 ); paramere as in Fig. 281 View Figs 277–295 . Orphnebius retunsus View in CoL subgroup. ............... ................................................................................................................................................................ retunsus View in CoL spec. nov.

– Pronotum (nearly) as dark as head. Antennae with at least antennomeres VI–X dark-brown to blackish. Eyes usually smaller. Aedeagus of different morphology. .................................................................................................................... 3

3. Head conspicuously transversely wedge-shaped; eyes strongly convex or somewhat wedge-shaped, situated at posterior margin of head ( Figs 28, 31 View Figs 27–39 ). Antennomere I strongly elongate, longer than the combined length of antennomeres II–IV ( Figs 6, 8 View Figs 1–26 ). Orphnebius dilatatus View in CoL subgroup. ................................................................................. 4

– Head not transversely wedge-shaped; eyes less strongly convex, not wedge-shaped. Antennomere I much shorter than the combined length of antennomeres II–IV. ......................................................................................................... 5

4. Eyes somewhat wedge-shaped ( Fig. 31 View Figs 27–39 ). Labrum with median tubercle and truncate anterior margin. Antennomeres V–X more transverse and more distinctly asymmetric ( Fig. 6 View Figs 1–26 ). Tibiae reddish. Median lobe of aedeagus and paramere as in Figs 233–235 View Figs 216–235 . .............................................................................................................. extensus View in CoL spec. nov.

– Eyes strongly convex, but not wedge-shaped ( Fig. 28 View Figs 27–39 ). Labrum without tubercle, anterior margin convexly produced in the middle. Antennomeres V–X weakly transverse and not distinctly asymmetric ( Fig. 15 View Figs 1–26 ). Tibiae brown. Median lobe of aedeagus and paramere as in Figs 229–231 View Figs 216–235 . Spermatheca as in Fig. 232 View Figs 216–235 . ........................ dilatatus View in CoL spec. nov.

5. Head of transversely quadrangular shape. Antennomeres V–X distinctly transverse and distinctly asymmetric. Clypeus largely membranous. Tergite VIII laterally with a cluster of thin setae on either side, posterior margin smooth or distinctly serrate. Pro- or mesotibiae sometimes modified (distinctly dilated). Median lobe of aedeagus distinctly sclerotized, dark, with short and mostly bifid ventral process. Paramere with slender condylite. Spermatheca with modified proximal portion. Orphnebius serratus View in CoL subgroup. ................................................................ 6

– Head of more or less orbicular shape. Clypeus with larger sclerotized portion. Tergite VIII without lateral clusters of thin setae, posterior margin never serrate. Pro- and mesotibiae unmodified. Median lobe of aedeagus less strongly sclerotized, ventral process never bifid. Spermatheca of different shape. ................................................................... 9

6. Posterior margin of tergite VIII smooth ( Fig. 260 View Figs 258–276 ). Median lobe of aedeagus and paramere as in Figs 253–256 View Figs 236–257 , 258–259 View Figs 258–276 . Spermatheca as in Fig. 257 View Figs 236–257 . ................................................................................................. bicuspis View in CoL spec. nov.

– Posterior margin of tergite VIII serrate ( Figs 240, 249, 252 View Figs 236–257 ). ........................................................................................ 7

7. Protibia dilated ( Fig. 39 View Figs 27–39 ); mesotibia unmodified. Median lobe of aedeagus with bifid ventral process ( Figs 236–238 View Figs 236–257 ). Paramere as in Fig. 239 View Figs 236–257 . Spermatheca as in Figs 241–243 View Figs 236–257 . .............................................................. serratus View in CoL spec. nov.

– Protibiae unmodified. Mesotibia smoothly dilated or strongly dilated.

8. Mesotibia smoothly dilated. Ventral process of aedagus not bifid ( Figs 244–246 View Figs 236–257 ). Paramere as in Fig. 247 View Figs 236–257 . ........... .................................................................................................................................................................... integer View in CoL spec. nov.

– Mesotibia conspicuously modified, strongly dilated and posterior surface with pronounced longitudinal excavation ( Fig. 38 View Figs 27–39 ). Spermatheca with very long and thin proximal portion ( Fig. 251 View Figs 236–257 ). .......................... latitibialis View in CoL spec. nov.

9. Posterior margins of tergite and sternite VIII truncate in the middle ( Fig. 272 View Figs 258–276 ). Eyes very large, occupying nearly all of lateral margins of head ( Fig. 49 View Figs 40–53 ). Antenna with pronounced sexual dimorphism, longer in male (1.3–1.4 mm) than in female (1.1–1.2 mm), male antenna with longer antennomere XI and with less transverse antennomeres VI–X. Median lobe of aedeagus with relatively small capsule and with ventral process of distinctive shape ( Figs 269–270 View Figs 258–276 ). Condylite of paramere strongly reduced ( Fig. 274 View Figs 258–276 ). Spermatheca as in Fig. 273 View Figs 258–276 . Orphnebius reductus View in CoL subgroup. ........................................................................................................................ reductus View in CoL spec. nov.

– Posterior margins of tergite and sternite VIII convex. Eyes in most species smaller. Antenna without pronounced sexual dimorphism. Median lobe of aedeagus with large capsule and a ventral process of completely different shape. Spermatheca of different shape. ...................................................................................................................................... 10

10. Antennomeres V–X conspicuously coniform, brown to dark-brown ( Fig. 11 View Figs 1–26 ). Pronotum strongly transverse, approximately 1.45 times as broad as long, and 1.3 times as broad as head ( Fig. 46 View Figs 40–53 ). Median lobe of aedeagus, paramere, and spermatheca as in Figs 263–265, 268 View Figs 258–276 . Orphnebius conicornis View in CoL subgroup. ............ fusicollis View in CoL spec. nov.

– Antennomeres V–X not coniform and more or less distinctly flattened, dark-brown to black. Pronotum less transverse and smaller in relation to head (exception: O. grandicollis View in CoL ). Male and female primary sexual characters different. O. hauseri View in CoL subgroup. ........................................................................................................................................ 11

11. Abdominal segment VIII infuscate ( Fig. 35 View Figs 27–39 ). Antennomere XI conspicuously elongate ( Fig. 16 View Figs 1–26 ). Sculpture of tergite VII composed primarily of dense longitudinal striae. ..................................................................................... 12

– Abdomen uniformly reddish. Antennomere XI less strongly elongate. Sculpture of tergite VII composed primarily of non-setiferous punctation (exception: O. grandicollis View in CoL ). ........................................................................................... 13

12. Antennomeres I–III reddish. Tibiae dark-reddish. Ventral process of aedeagus longer, more slender in ventral view ( Figs 216–217 View Figs 216–235 ). Paramere as in Figs 218–219 View Figs 216–235 . ............................................................................ fuscapicalis View in CoL spec. nov.

– Antennomeres I–III blackish-brown. Tibiae dark-brown. Ventral process of aedeagus shorter, broader in ventral view ( Figs 220–221 View Figs 216–235 ). Paramere as in Fig. 222 View Figs 216–235 . ............................................................................. nigrapicalis View in CoL spec. nov.

13. Pronotum large in relation to head, 1.4 times as broad as long and approximately 1.25 times as broad as head ( Fig. 22 View Figs 1–26 ). Antenna 1.4 mm long ( Fig. 17 View Figs 1–26 ). Sculpture of tergite VII predominantly composed of dense longitudinal striae. Median lobe of aedeagus and paramere as in Figs 212–215 View Figs 197–215 . ......................................... grandicollis View in CoL spec. nov.

– Pronotum distinctly smaller in relation to head, 1.3 times as broad as long and 1.2 times as broad as head at most. Antenna much shorter, <1.2 mm long. Sculpture of tergite VII predominantly composed of non-setiferous punctation. Male primary sexual characters different. ............................................................................................................ 14

14. Eyes much larger, occupying all of lateral margins of head, approximately three times as long as distance from posterior margin of eye to posterior constriction of head ( Fig. 24 View Figs 1–26 ). Median lobe of aedeagus and paramere as in Figs 202–204 View Figs 197–215 . Spermatheca as in Fig. 206 View Figs 197–215 . .......................................................................................... cernens View in CoL spec. nov.

– Eyes distinctly smaller, approximately as long as distance from posterior margin of eye to posterior constriction of head ( Fig. 25 View Figs 1–26 ). Median lobe of aedeagus and paramere as in Figs 208–210 View Figs 197–215 . ................................. lunatus View in CoL spec. nov.

15. Sternites III–V without, or with inconspicuous, postero-lateral processes. .............................................................. 16

– At least sternite III, IV, or V with long postero-lateral processes. .............................................................................. 17

16. Head and pronotum weakly transverse; elytra without tubercle near suture ( Fig. 85 View Figs 84–101 ). Sternites III–V unmodified ( Fig. 91 View Figs 84–101 ). Antenna very slender, 1.9–2.2 mm long; antennomeres V–VII oblong, IX–X weakly transverse ( Fig. 58 View Figs 54–83 ). Metafemur distinctly bicoloured, with the basal half yellowish and the apical half blackish. Tergite VIII oblong and with two large tooth-like projections posteriorly ( Fig. 320 View Figs 317–339 ). Median lobe of aedeagus, paramere, and spermatheca as in Figs 317–318, 324 View Figs 317–339 . ....................................................................................................................... spoliatus View in CoL spec. nov.

– Head and pronotum more transverse; elytra with a small tubercle near suture ( Fig. 102 View Figs 102–118 ). Sternite IV and paratergite IV with a short postero-lateral process on either side ( Fig. 117 View Figs 102–118 ). Antenna much shorter, 1.2 mm long, distinctly incrassate apically, and with distinctly transverse antennomeres V–X ( Fig. 64 View Figs 54–83 ). Metafemur blackishbrown. Tergite VIII transverse, posterior margin distinctly concave and finely serrate ( Fig. 351 View Figs 340–358 ). Spermatheca as in Fig. 353 View Figs 340–358 . ............................................................................................................................................ carinatus View in CoL spec. nov.

17. Head truncate or even weakly concave posteriorly; posterior angles marked ( Figs 89–90 View Figs 84–101 ). Eyes enormous, nearly reaching posterior margin of head and more than twice as long as distance from posterior margin of eye to posterior constriction of head in dorsal view ( Fig. 89–90 View Figs 84–101 ). ......................................................................................................... 18

– Head convex posteriorly, lateral and posterior margin practically forming a semi-circle, posterior angles obsolete. Eyes much smaller, approximately as long as, or slightly longer than distance from posterior margin of eye to posterior constriction of head in dorsal view ( Figs 86–87 View Figs 84–101 ). ........................................................................................ 19

18. Sternite V with long lateral process; sternites III–IV weakly modified ( Fig. 97 View Figs 84–101 ). Antenna shorter and finer, 1.2 mm long ( Fig. 61 View Figs 54–83 ). Posterior margin of tergite VIII with a long lateral tooth and two shorter sublateral teeth on either side ( Fig. 343 View Figs 340–358 ). Small species, length of forebody 1.6 mm. Median lobe of aedeagus and paramere as in Figs 340–342 View Figs 340–358 . ....................................................................................................................................................................... vates View in CoL spec. nov.

– Sternite V unmodified; paratergite IV and sternite IV each with a pronounced postero-lateral process on either side, these processes contiguous ( Fig. 101 View Figs 84–101 ). Antenna longer and more massive, approximately 1.8 mm long ( Fig. 63 View Figs 54–83 ). Posterior margin of tergite VIII concave and serrate ( Fig. 348 View Figs 340–358 ). Larger species, length of forebody 2.5 mm. Spermatheca as in Fig. 350 View Figs 340–358 . ..................................................................................................................... baccillatus View in CoL spec. nov.

19. Sternites III and IV each with a long postero-lateral process on either side ( Figs 92–94 View Figs 84–101 ). Elytral punctation very fine and sparse ( Fig. 86 View Figs 84–101 ). Antenna shorter, approximately 1.5 mm long; antennomeres VI–VII not flattened and VI–X not oblong ( Fig. 59 View Figs 54–83 ). Metafemur not distinctly bicoloured, dark-brown. Tergite VIII transverse, with a posterior excision, in postero-median portion with a tubercle ( Fig. 328 View Figs 317–339 ). Sternite VIII conspicuously pointed posteriorly ( Figs 329–331 View Figs 317–339 ). Median lobe of aedeagus of distinctive shape, ventral process knife-shaped ( Figs 325–326 View Figs 317–339 ). Spermatheca as in Fig. 333–334 View Figs 317–339 . ............................................................................................................. cultellatus View in CoL spec. nov.

– Only sternite III with a long postero-lateral process on either side ( Fig. 95 View Figs 84–101 ). Elytral punctation conspicuously coarsely granulose and rather dense ( Fig. 87 View Figs 84–101 ). Antenna much longer, approximately 2.0 mm long; antennomere I conspicuously club-shaped, strongly dilated apically; antennomeres III–VII distinctly flattened and VI–IX oblong ( Fig. 60 View Figs 54–83 ). Metafemur distinctly bicoloured, blackish with the basal third pale-yellowish. Tergite VIII oblong, posteriorly with a long median, two even longer lateral, and four smaller teeth ( Fig. 338 View Figs 317–339 ). Sternite VIII convex posteriorly ( Fig. 339 View Figs 317–339 ). Median lobe of aedeagus and paramere as in Figs 335–337 View Figs 317–339 . .................................................. septemcuspis View in CoL spec. nov.