Oxypoda (Atlantoxypoda) bicornuta ASSING, 2016

Assing, Volker, 2016, On the Staphylinidae of the Greek island Karpathos (Insecta Coleoptera), Linzer biologische Beiträge 48 (1), pp. 235-263 : 248-251

Oxypoda (Atlantoxypoda) bicornuta ASSING nov.sp. ( Figs 11-22 )

T y p e m a t e r i a l: Holotype 3: " Greece: Karpathos [21], 3 km SSW Spoa, 35°36'42''N, 27°08'08''E, 760 m, pine litter, 30.XII.2015, V. Assing / Holotypus 3 Oxypoda bicornuta sp.n. det. V. Assing 2016" (cAss) . Paratypes: 1233, 4♀♀: same data as holotype (cAss) ; 13: " Greece: Karpathos [5], N Volada, pista E Lastos 35°34'48''N, 27°09'30''E, 680 m, pine forest, 24.XII.2015, V. Assing" (cAss) ; 13: " Greece: Karpathos [9], W Spoa, 35°38'56''N, 27°07'56''E, 230 m, stream valley, sifted, 25.XII.2015, V. Assing" (cAss) ; 13, 1♀: " Greece: Karpathos [15], Kali Limni, 35°35'32''N, 27°08'15''E, 870 m, plateau, under stones, 28.XII.2015, V. Assing" (cAss) ; 1♀: " Greece: Karpathos [22], 3 km SSW Spoa, 35°36'49''N, 27°08'08''E, 770 m, pine litter, 30.XII.2015, V. Assing" (cAss) ; 1 ex.: " Greece, Karpathos , Spoa, 500 mNN, 23.04.1994, leg. J. Frisch " (cAss) .

E t y m o l o g y: The specific epithet (Latin, adjective: with two horns) alludes to the conspicuous pair of processes at the base of the ventral process of the aedeagus.

D e s c r i p t i o n: Body length 2.8-3.5 mm; length of forebody 1.3-1.5 mm. Habitus as in Fig. 11 . Coloration: head brown to black; pronotum pale-reddish to brown, paler than head; elytra yellowish-red to dark-reddish, with the scutellar and postero-lateral portions usually slightly infuscate; abdomen blackish-brown to blackish, with the posterior margins of tergites III-VI, the posterior portion of tergite VII, and all of segments VIII-X reddish; legs yellowish; antennae dark-brown with the basal 2-3 antennomeres dark-yellowish; maxillary palpi dark-yellowish with palpomere III more or less distinctly infuscate.

Head ( Fig. 12 ) approximately as long as broad or indistinctly transverse, of suborbicular shape; punctation fine and dense; interstices with shallow microreticulation. Eyes of moderate size, weakly convex, distinctly shorter than postocular region in dorsal view. Antenna 0.7-0.8 mm long and shaped as in Fig. 13 . Maxillary palpus elongate, palpomere III approximately four times as long as broad.

Pronotum ( Fig. 12 ) approximately 1.25 times as broad as long and 1.4 times as broad as head, widest behind middle; posterior angles obsolete; punctation fine and very dense; interstices with extremely shallow microreticulation barely visible even at high magnification (100 x).

Elytra ( Figs 12, 14 ) approximately 0.9 times as long as pronotum; punctation dense and moderately fine; interstices without microsculpture. Hind wings dimorphic, reduced in micropterous morph, fully developed in macropterous morph. Metatarsomere I as long as, or slightly longer than, the combined length of II-IV.

Abdomen slightly narrower than elytra; segments III-VI of subequal width; punctation fine and very dense, only slightly less dense on tergite VII ( Fig. 15 ) than on tergite V; interstices mostly without microsculpture (indistinct traces may be visible at high magnification in posterior portions of tergites VI-VIII); posterior margin of tergite VII with palisade fringe.

3: middle of sternite VIII convexly produced; median lobe of aedeagus ( Figs 16-19 ) 0.40-0.44 mm long and of conspicuous shape, at base of ventral process with a pair of processes; crista apicalis strongly projecting in lateral view; parameres ( Fig. 20 ) enormous (approximately 0.8 mm), nearly twice as long as median lobe, with moderately long apical lobe and with pronounced velum.

♀: posterior margin of sternite VIII broadly convex; spermatheca shaped as in Fig. 21.

C o m p a r a t i v e n o t e s: In general habitus, elongate maxillary palpi, and dense punctation O. bicornuta is similar to the sympatric (present also in Karpathos), widespread, parthenogenetic O. lurida , from which it differs by slightly larger body, darker antennae, the usually more colourful appearance (head more strongly contrasting with the paler pronotum and elytra; elytra bicoloured), the wing dimorphism, and by the presence of males. The spermathecae of both species are nearly identical in shape, but that of O. lurida is only weakly sclerotized. Based on the similar, undoubtedly synapomorphic, modifications of the aedeagus (median lobe with pair of process at base of ventral process and with strongly projecting crista apicalis; paramere of enormous size and with strongly developed velum), O. bicornuta is most closely related to a species from southern Turkey, which is described in an appendix to this article. For characters distinguishing both species see the description in the appendix.

Oxypoda bicornuta is tentatively assigned to Atlantoxypoda ZERCHE, 1996, based on the general resemblance to O. lurida , which is currently included in this subgenus, too.

D i s t r i b u t i o n a n d n a t u r a l h i s t o r y: The specimens were found in six localities in the southern part of the island (northwards to the environs of Spoa). Two specimens were collected from under stones in a plateau with grass and phrygana vegetation, the remainder was sifted from litter and herb roots beneath old pine trees and in a stream valley. The vast majority of specimens (17 exs.) was found in the type locality by sifting pine litter and herb roots beneath an old pine tree in the shade of large rocks ( Fig. 22 ). The altitudes range from 230 to 870 m. Eight of the specimens are macropterous, the remainder brachypterous.

Figures

Figs 11-21: Oxypoda bicornuta nov.sp.: (11) habitus; (12) forebody; (13) antenna; (14) sutural portion of elytra; (15) median portion of abdominal tergite VII; (16-17) median lobe of aedeagus in lateral view; (18) median lobe of aedeagus in ventral view; (19) base of median lobe in ventral view; (20) paramere; (21) spermatheca. Scale bars: 11: 1.0 mm; 12: 0.5 mm; 13-15, 20: 0.2 mm; 16-19, 21: 0.1 mm.

Fig. 22: Type locality of Oxypoda bicornuta nov.sp. (sample number 21).