Ochthebius (Ochthebius) bernard, Ribera & Hernando & Cieslak, 2019

Ribera, Ignacio, Hernando, Carles & Cieslak, Alexandra, 2019, Aquatic Coleoptera of North Oman, with description of new species of Hydraenidae and Hydrophilidae, Acta Entomologica Musei Nationalis Pragae 59 (1), pp. 253-272 : 260-263

Ochthebius (Ochthebius) bernard sp. nov.

( Figs 16 , 20 )

Type locality. Source of wadi Bani Awf in Jebel Al-Hajar, Oman (Loc. 4; Figs 1 , 5, 6 ).

Type material. HOLOTYPE: ♁ ( NHMW), “4 Oman 6.4.2010 J.Al-Akhdar // source of wadi Bani Awf , on rock // N23 10 36.2 E57 24 34.1 1300m // Ribera, Cieslak & Hernando leg.”, aedeagus dissected and mounted in DMHF on a transparent card, with holotype label . PARATYPES (138 spec.) ( CCHB, IBEB, MNCN, NHMW, NMPC): 2 ♀♀, same data as holotype, with paratype labels; 3 ♁♁ 3 ♀♀, “1 Oman 5.4.2010 J. Al-Akhdar // Rd J. Shams, ca. Ghul spring with pools // N23 11 01.7 E57 08 30.4 908m // Ribera, Cieslak & Hernando leg.”, with paratype labels (1♁ used for DNA extraction, voucher number IBE-RA96); 130 spec. “3 Oman 6.4.2010 J. Al-Akhdar // rd.Tanuf-Hat, residual pools in wadi // N23 05 36.2 E57 25 56.6 1307m // Ribera, Cieslak & Hernando leg.”, with paratype labels (1 ♁ used for DNA extraction, voucher number IBE-AN1102).

Additional material studied. 1 ♀, “8 Oman 7.4.2010 Murri env. // wadi Bani Ghafir, stream with pools // N23 29 46.2 E56 53 34.8 759m // Ribera, Cieslak & Hernando leg.”

Description. Habitus as in Fig. 16 . Body length: 1.95–2.20 mm; width: 0.90–0.95 mm. With a blackish metallic hue, immature specimens paler (dark brown); palpi dark brown, antennae yellowish except for the brown club, legs dark brown.

Upper surface of head with irregular, adpressed fine whitish setae. Labrum deeply incised, anteriorly upturned (more in males). Frontoclypeal suture distinct, strongly arched. Surface of head with a shagreened, almost rugose appearance, especially around two depressed fovea on vertex. Eyes large, with small, recumbent setae among ocelli. With two large ocelli behind fovea.

Pronotum trapezoidal, almost as wide as long; surface covered with same type of setae as on head; anterior margin straight in middle; anterior angles straight; lateral margin irregularly defined. Hyaline membrane narrow at anterior and posterior margins, very wide at posterior corners. Surface very densely punctate-granulated, with a rugose but shiny appearance; disc with a shallow irregular median groove and poorly defined, irregular lateral furrows.

Elytra oval; with regular rows of punctures and small tubercles, giving a rugose appearance; with a strong, adpressed seta on anterior part of each puncture. Lateral rim smooth, wider on females. Membranous wings well developed.

Legs short and robust, with rows of strong spine-like setae, without natatorial setae.

Ventral surface black, elytral epipleura and hypomera dark brown; covered with fine, dense uniform pubescence. Margins of metaventrite and abdominal ventrites with longer setae, more orderly disposed.

Aedeagus ( Fig. 20 ) with main piece evenly curved, with uniform width. Distal lobe regularly expanded, with a tubuliform apex. Parameres inserted near median part of main piece, not reaching its apex.

Differential diagnosis. The new species belongs to the Ochthebius metallescens group, being most closely related to O. hivae Jäch et al., 2013 from western Iran. It differs from this species in the body colouration (brownish in O. hivae , black with metallic reflections in O. bernard sp. nov.), the less strongly granulated elytra, pronotum and head of O. hivae , the more acuminate elytra in O. hivae , and the shape of the aedeagus (see JÄCH et al. 2013). As noted in JÄCH et al. (2013), the shape of the distal lobe of the aedeagus of O. hivae is unusually variable, but none of the different models figured matches the shape of the distal lobe of O. bernard sp. nov., specially those of the type locality (see Figs 2 and 3 in JÄCH et al. 2013). The two species differ by ca. 10% in their COI-3 gene, as measured with one specimen of O. hivae from the type locality (specimen voucher IBE-RA744, Iran: prov. Khuzestan, Behbahan, Morvarid spring, 4.ix.2010, leg. E. Irani; VILLASTRIGO et al. 2019). Despite the strong resemblance of the external morphology (see also JÄCH et al. 2013), O. bernard sp. nov. does not seem to be closely related to the only other species of the O. metallescens group from the Arabian Peninsula, O. wurayah Jäch & Delgado, 2010 (unpublished results), with which it was found to coexist in our locality No. 4 ( Table 3 ; Figs 5, 6 ).

Etymology. We name this species after the first and last authors’ son, Bernard. Noun in nominative, standing in apposition.

Notes on the habitat. The species was most common in localities Nos 3 and 4 ( Figs 1 , 4–6 ; see description under Hydraena naja sp. nov. above).

Distribution. So far only known from the central Al-Hajar mountains ( Fig. 1 ).

Figures

Figs 14–17. Habitus of new species: 14 – Hydraena naja sp. nov.; 15 – Ochthebius alhajarensis sp. nov.; 16 – Ochthebius bernard sp. nov.; 17 – Agraphydrus elongatus sp. nov. Scale bars: 1 mm.

Figs 18–21. Aedeagus of new species: 18 – Hydraena naja sp. nov.; 19 – Ochthebius alhajarensis sp. nov.; 20 – Ochthebius bernard sp. nov.; 21 – Agraphydrus elongatus sp. nov. Scale bars: 0.2 mm.

Fig. 1. Sampled localities (see Table 1 for details).

Figs 2–7. Some of the sampled localities in north Oman. 2 – Loc. No. 1: Ghul spring with pools; 3 – No. 2: residual pools in wadi in Bahla city; 4 – Loc. No. 3: residual pools in wadi; 5 – Loc. No. 4: source of wadi Bani Awf; 6 – Loc. No. 4: source of wadi Bani Awf; 7 – Loc. No. 5: wadi Bani Awf. See Table 1 for details on the localities, and Fig. 1 for their geographical location.