Byrrhinus helicophallus, 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 : 180-182

Byrrhinus helicophallus sp. nov.

( Figs 5 , 10–11)

Type locality. Yemen, Al Hudaydah Governorate, Jabal Bura ( Fig. 15C ).

Type material. HOLOTYPE: J ( NMPC), ‘ YEMEN, Al Hudaydah gov. / Jabal Bura valley forest NP / (stream valley; at light), 240-350m / 14º52.4-5ʹN, 43º24.6- 25.2ʹE / J. Bezděk leg. 4.xi.2010 ’ [genitalia and abdominal ventrites mounted in DMHF on two transparent cards pinned with the specimen] . PARATYPES (26 specimens, CHBS, IBEB, NHMW, NMPC): 6 spec.: same data as holotype ; 4 spec., same data as holotype, but L. Purchart leg. ; 6 spec. same data as holotype, but Jiří Hájek leg. ; 1 spec.: ‘W YEMEN, Jabal Bura´ NEE / Al Hudaydah, N14º52ʹ / E43º24ʹ, 261- 600 m, / 9.-11.IV.2007, lgt. P. Kabátek’ ; 3 spec.: ‘W YEMEN, Jabal Bura’ , / NEE Al Hudaydah, N14º52ʹ / E43º24ʹ, 225-600m / 30.X.-1.XI.05, lgt. S. Kadlec’, ‘ex coll. S. Kadlec / National Museum / Prague, Czech Republic’ ; 5 spec.: ‘W YEMEN, Jabal Bura’ NEE / Al Hudaydah, N14º52ʹ / E43º24ʹ, 225-600 m, 30.X.- / 1.XI.05, lgt. P. Kabátek’ ; 1 J: ‘W YEMEN, 20 km NW / Dhawran , N14º40ʹ E44º13ʹ / 1794 m, 29.X.2005, [‘ ex larva ’ crossed with pencil], / lgt. S. Kadlec’, ‘ex coll. S. Kadlec / National Museum / Prague, Czech Republic’ [immature specimen, genitalia dissected and mounted in DMHF on a transparent card pinned with the specimen] .

Dubious specimens. 2 ♀♀ ( NMPC): ‘ ETHIOPIA, Dire Dawa, / 9º39,27ʹN, 41º55,813ʹE, / 1133 m, 5.vi.2011, / V. Hula & J. Niedobová leg.’ [genitalia dissected and mounted in DMHF on separate transparent cards pinned with the respective specimens].

Description. Length 3.1–3.3 mm; maximum width 1.8–1.9 mm. Body oval, strongly convex ( Fig. 5 ). Dorsal surface brown to dark brown, covered with yellowish, long, dense erect pubescence. Body appendages paler than body.

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

Pronotum transverse (ratio median length / width at base = 0.45–0.47); anterior margin straight, without crenulations, very finely bordered; posterior margin with a strong double sinuation; lateral margins arched, with prominent borders. Puncturation similar to that on head; pubescence slightly decumbent posteriorly. Hypomeron flat, without depressions or fossae.

Elytra with a weak humeral callus; lateral margins bordered from humerus to apex, finer towards apex; apex acuminate, with a locking device. Membranous wings well developed. Surface of elytra with strong irregular punctures; pubescence slightly bent backwards.

Ventral surface with strong and dense puncturation, with dense, long recumbent pubescence except on metaventrite, which has only isolated setae. Surface of abdominal ventrites with uniform, fine and very dense punctures. Three first ventrites connate, surface between punctures with polygonal reticle, with median pore; from ventrite IV without polygonal reticle. Inter-metacoxal plate on ventrite I triangular, strongly acuminate; abdominal ventrite I with depressions for reception of metafemora and metatibiae. Ventral surface with pubescence finer than on dorsal surface, recumbent.Apical abdominal ventrite strongly emarginate, with blunt median protuberance; pubescence denser in medial area (in males denser than in females). When seen with transmitted light, posterior margin of apical abdominal ventrite of male with a series of likely glandular tubules, not visible in dry specimens.

Protibia without preapical comb of setae or denticles; apex of protibia with sulcus for reception of tarsi on external surface; apex of meso- and metatibiae with anterior surface flattened, not forming sulcus.

Male genitalia (Fig. 10). Parameres, median lobe of aedeagus and phallobase twisted, strongly asymmetrical and strongly sclerotized. Genital segment asymmetrical, strongly sclerotized; struts asymmetrical, with different length; short strut fused with lamina. Ventrite VIII U-shaped, with narrow apical membranous lamina. Spiculum as in Fig. 10D.

Female genitalia. Ovipositor as in Fig. 11.

Differential diagnosis. Byrrhinus helicophallus sp. nov. does not seem to be closely related to any of the Afrotropical species figured by DELÈVE (1968): the whole aedeagus is strongly asymmetrical, heavily sclerotized, with a very peculiar spiculum. Only one of the known African species has an asymmetrical aedeagus ( B. bomansi ( Delève, 1968) ; see DELÈVE 1968: Fig. 43), but nothing comparable to that of B. helicophallus sp. nov. which is more likely to be related to some Middle Eastern species (unpublished observations).

Etymology. Named in reference to the shape of the aedeagus, twisted like a helix; noun in apposition.

Collection circumstances. Most species were collected at light. See notes on P. sabaeanus sp. nov. for description of the type locality.

Distribution ( Fig. 16 ). So far only known from continental Yemen, likely to be present in Ethiopia.

Remarks. The genitalia of the two females from Ethiopia appear identical to that of the specimens from Yemen. There are small differences in the external morphology, which could well be due to intraspecific variability, but in the absence of males any identification remains uncertain. In SPANGLER et al. (2001) B. marginatus Champion, 1923 is recorded from Pakistan, but we have not been able to trace the origin of this record and it is likely a mistake. Byrrhinus marginatus was described from the central Himalayas (Kumaon, CHAMPION 1923), and no other records have been published after its description.

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. 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.