Byrrhinus socotrensis, Hernando & Ribera & Csic, 2014

Hernando, Carles, Ribera, Ignacio & Csic, 2014, The Limnichidae (Coleoptera) of the Arabian Peninsula and the island of Socotra, Acta Entomologica Musei Nationalis Pragae 54, pp. 173-189 : 182-185

Byrrhinus socotrensis sp. nov.

( Figs 4 , 12–13 )

Type locality. Yemen, Socotra, Dixam plateau, wadi Esgego ( Fig. 15D ).

Type material. HOLOTYPE: J ( NMPC), ‘Yemen, Soqotra Is., 2003 / 2.-3/xii., Dixam plateau / WADI ESGEGO, 300m / N12º28ʹ09 ʺE54º00ʹ36ʺ / [GPS], David Král lgt.’, ‘ YEMEN – SOQOTRA / 2003 / Expedition; Jan Farkač, / Petr Kabátek & David Král’ [genitalia and abdominal ventrites mounted in DMHF on a transparent card pinned with the specimen]. PARATYPES (87 specimens, CHBS, CULS, IBEB, NHMW, NMPC, PLFG): 21 spec.: same data as holotype; 8 spec.: ‘ Yemen, Soqotra Is., Dixam / plateau, WADI ESGEGO / 2.-3.xii.2003, N 12º 28ʹ 09ʺ / E 54º 00ʹ 36ʺ, 300 m [GPS] / Leg. P. Kábatek’, ‘ YEMEN – SOQOTRA / 2003 / Expedition; Jan Farkač, / Petr Kabátek & David Král”; 8 spec.: ‘ Yemen, Soqotra Is.: / 2.-3.xii.2003 / Dixam plat.: WADI ESGEGO / N 12º28ʹ09ʺ E 54º00ʹ36ʺ / 300 m [GPS]: Jan Farkač lgt.’, ‘ YEMEN – SOQOTRA / 2003 / Expedition; Jan Farkač, / Petr Kabátek & David Král’; 3 spec.: ‘ Yemen, Soqotra Is., Dixam / plateau, WADI ESGEGO / 2.-3/xii.2003, N 12º28ʹ09ʺ / E 54º00ʹ36ʺ, 300m [GPS] / Leg. P. Kabátek,’, ‘ YEMEN – SOQOTRA 2003 / Expedition; Jan Farkač, / Petr Kabátek & David Král’; 12 spec.: ‘ YEMEN, SOCOTRA ISLAND / Homhil protected area / open woodland with Boswellia / Dracaena trees; 10.-11.vi.2012 / 12º34.5ʹN, 54º18.5ʹE, 360-500m’, ‘ SOCOTRA expedition 2012 / J. Bezděk, J. Hájek,V. Hula, / P. Kment, I. Malenovský, / J. Niedobová & L. Purchart leg.’; 17 spec.: ‘ YEMEN, SOCOTRA Island / Zemhom area, 270-350m / N 12º30ʹ58ʺ, E 54º06ʹ39ʺ / 3.-4.ii.2010, at light / L. Purchart & J. Vybíral lgt.’; 3 spec.: ‘ YEMEN, SOCOTRA ISLAND / Dixam plateau 14.-15.vi.2012 / Firmihin, Dracaena woodland / 12º28.6ʹN, 54º01.1ʹE, 490 m’, ‘ SOCOTRA expedition 2012 / J. Bezděk, J. Hájek,V.Hula, / P. Kment, I. Malenovský, / J. Niedobová & L. Purchart leg.’; 2 spec.: ‘ YEMEN, SOCOTRA Island / Dixam plateau / Firmihin ( Dracaena forest) / 12º28.6ʹN, 54º01.1ʹE, 490 m / J. Bezděk leg., 15.-16.xi.2010 ’; 3 spec.: ‘ YEMEN, SOCOTRA Island / Noged plain (sand dunes) / Sharet Halma vill. env. / 12º21.9ʹN, 54º05.3ʹE, 20 m / Jiří Hájek leg. 10-11. xi.2010 ’; 2 spec.: ‘ Yemen, Soqotra Is., HADIBO / env., 21.xi.-12.xii.2003, N 12º / 65ʹ02ʺ E 54º02ʹ04ʺ, ca. 10- / 100m [GPS], leg. P. Kabátek’, ‘ YEMEN – SOQOTRA / 2003 / Expedition; Jan Farkač, / Petr Kabátek & David Král’; 1 spec.: ‘ YEMEN, SOCOTRA Island / wadi Ayhaft / 12º36.5ʹN, 53º58.9ʹE, 200m / Jiří Hájek leg. 7-8. xi.2010 ’; 1 spec.: ‘ Yemen, Soqotra Is. / 21.xi.-12.xii.2003 /HADIBO env., ca. 10-100m / N12º65ʹ02ʺ E54º02ʹ04ʺ / [GPS], David Král lgt.’, ‘ YEMEN – SOQOTRA 2003 / Expedition; Jan Farkač, / Petr Kabátek & David Král’; 2 spec.: ‘ YEMEN, SOCOTRA Island / Deiqub cave, 12.vi.2012 / cave & Croton socotranus + / Jatropha unicostata shrubland; / 12º23.1ʹN, 54º00.9ʹE, 115 m’, ‘ SOCOTRA expedition 2012 / J. Bezděk, J. Hájek, V. Hula, / P. Kment, I. Malenovský, / J. Niedobová & L. Purchart leg.’; 1 spec.: ‘ SOCOTRA ( YEMEN) / Zam Hom / 7.IV.2008 at lamp / leg. A. Carapezza’; 3 exx.: ‘ SOCOTRA: W. Ayheft / 28.II-. 1.III.2009 – leg. P. / Lo Cascio & F. Grita’ [three specimens in separate cards in the same pin].

Description. Length 2.3–2.4 mm; maximum width 1.1–1.2 mm. Body elongate, almost subparallel ( Fig. 4 ). Dorsal surface brownish, covered with yellowish, long, dense erect pubescence. Body appendages slightly paler than body.

Head. Eyes slightly convex, visible from above; upper margin of eyes bordered, border reaching anteriorly insertion of antennae; extended posteriorly to eyes till posterior margin of head. Surface of head posterior to eyes flat, without depressions or fossae with erect pubescence; surface with fine and sparse puncturation, surface between punctures smooth and shiny. Antennae strongly pubescent, antennomeres I–X symmetrical, antennomere XI asymmetrical, apical four antennomeres forming loose club.

Pronotum not very transverse (ratio median length / width at base = 0.50–0.53); anterior margin of pronotum straight, without crenulations, finely bordered; posterior margin with a strong double sinuation; lateral margins slightly arched, strongly bordered. Pubescence and puncturation similar to that on head. Hypomeron flat, without depressions or fossae.

Elytra with a weak humeral callus; lateral margins bordered from humerus to apex; apex acuminate, with a locking device. Membranous wings well developed. Surface with strong punctures, forming regular series; pubescence erect, slightly bent backwards.

Ventral surface with dense and uniform strong puncturation, covered with very dense, uniform, long pubescence, including metaventrite. Surface of abdominal ventrites with uniform, fine and very dense punctures; surface between punctures reticulated-chagreened. Three first ventrites connate (fused). Metaventrite with longitudinal striae. Inter-metacoxal plate on ventrite I triangular, strongly acuminate; first abdominal ventrite with depressions for reception of metafemora and metatibiae. Pubescence finer than on dorsal surface, recumbent. Last abdominal ventrite strongly emarginate, with a blunt medial protuberance; pubescence denser in medial area (in males denser than in females).

Protibia without preapical comb of setae or denticles; apex of protibia with sulcus for reception of tarsi on external surface (shallower than in B. helicophallus sp. nov.); apex of meso- and metatibiae with anterior surface flattened, but not forming sulcus.

Male genitalia ( Fig. 12 ). Median lobe of aedeagus shorter than parameres, apex acuminate. Parameres symmetrical, not articulated (as typical of the genus); wider at base, narrower towards apex; apex rounded. Base asymmetrical. Genital segment asymmetrical, strongly sclerotized; struts asymmetrical, with different length. Ventrite VIII U-shaped, with wide apical membranous lamina. Spiculum strongly bilobed.

Female genitalia. Ovipositor as in Fig. 13.

Etymology. Named after the island of Socotra.

Collection circumstances. Most specimens were collected at light, in the proximity of a wadi on stony and sandy substratum and open woodland ( Fig. 15D ).

Distribution ( Fig. 16 ). So far only known from the island of Socotra, in the Indian Ocean, where it seems to be common and widespread.

Remarks. According to DELÈVE (1968) the species would have to be included in his group III, with species with median lobe of the aedeagus with subparallel sides, slightly narrowed at the apex. Within this group, it will be the most similar to the species with bifid spicula, B. grossepunctatus ( Delève, 1968) and B. seydeli ( Delève, 1968) from the Democratic Republic of the Congo.

Figures

Figs 1–5. Habitus of the Limnichidae of Arabian Peninsula and Socotra Islands. 1 – Pelochares sinbad sp. nov.; 2 – P. sabaeanus sp. nov.; 3 – Limnichus arabicus sp. nov.; 4 – Byrrhinus socotrensis sp. nov.; 5 – B. helicophallus sp. nov. Upper scale bar applied to Figs 1–3, bottom scale bar to Figs 4–5.

Fig. 12. Male genita- lia of the holotype of Byrrhinus socotrensis sp. nov. A – aedea- gus (with spiculum); B – spiculum (of a different specimen); C – ventrite VIII; D – genital segment.Scale bar: 0.5 mm.

Fig. 15. Representative habitats where specimens of Limnichidae were found. A – Oman, wadi 15 km southwest of Sur, type locality of Pelochares sinbad sp. nov.; B – Oman, wadi west of Qalhat, also with P. sinbad sp. nov.; C – Western Yemen, Jabal Bura, type locality of Pelochares sabaeanus sp. nov. and Byrrhinus helicophallus sp. nov.; D – Socotra, wadi Dirhor (Esgego), type locality of B. socotrensis sp. nov.(photos:A–B –A. Cieslak; C–D – J. Hájek)

Fig. 16. Distribution of the known Arabian Limnichidae. Blue circles – Pelochares sinbad sp. nov.; green circles – P. sabaeanus sp. nov.; red circles – Byrrhinus helicophallus sp. nov.; yellow circles – B. socotrensis sp. nov.; purple circle – Limnichus arabicus sp. nov. With question marks, specimens of uncertain identity from Ethiopia; inset – detailed distribution of B. socotrensis sp. nov. in Socotra.