Omanocossonus sabulosus Hlaváč, Skuhrovec & Pelikán, 2020

Hlaváč, Peter, Skuhrovec, Jiří & Pelikán, Jan, 2020, A new, peculiar genus of Cossoninae (Coleoptera, Curculionidae) from Oman with description of a new species, larva and notes on biology, Zootaxa 4768 (1), pp. 129-142 : 133-134

Omanocossonus sabulosus Hlaváč, Skuhrovec & Pelikán , sp. nov.

( Figs 1 A–B, 2A–B, 3A–E, 4A–H)

Material examined: Holotype, ♂: S Oman, Dhofar Gov., 6 km NW of Mirbat (seacoast), 23.9.2018, lgt. Jan Pelikán / 17°1’30.754”N, 54°38’46.126”E, 5m, sand dunes, in roots Calotropis procera . NMPC . Paratypes: 8♂, 4♀, 194 sps.: the same data as holotype. 248 sps.: the same data as holotype but collected by T. Kopecký. All these para- types are deposited in the following collections: BMNH, CMNC, HNHM, MMBC, MNMS, NHRS, NMPC, NMW, OUMNH, SMNS, ZSMC, ECC, JKC, JPC, JSC, MKC, PHC, RBC, TKC. 1♂: OMAN, Dhofar reg., Mirbat beach, 24.XI.2017, T. Lackner lgt. PHC.

Description. Body convex, shiny reddish-brown, legs and antennae of same colour ( Figs 1 A–B). Length 2.9– 3.5 mm, maximal width of elytra 1.1–1.4 mm.

Head widest as base, with sparse, uneven punctures; punctures on rostrum dense, on apex of rostrum contigu- ous; rostrum short, about as long as wide, length/width ratio = 0.95–1.05, slightly convex, 0.30–0.40 mm long, about 6–7 times as long as head behind eyes; antennal scrobe slightly visible dorsally, by right angle curved down- ward before eyes, short, deep, the point of antennal insertion located slightly before middle of rostrum.

Antennae stout, with sparse setae, antennal club with dense, golden pubescence; antennal scape long, peduncu- late at apex, about 5.25–5.75 times as long as antennomere II and about 1.1–1.2 times as long as funicle; funicle with seven antennomeres, about 1.6–1.7 mm long; funicle antennomere I stout, wider than II and about 1.5 times as long as II, all funicular antennomeres slightly expanded from base to apex, II elongate, III–VII transverse, II about 1.1 times as long as III, III–VII subequal in length, VII widest, antennal club with three completely fused antennomeres, lacking any trace between them, apically pointed, 1.20–1.35 times as long as wide; eyes longitudinally oval, flat, diameter of eye about 1.25 times distance from posterior margin of eye to pronotal margin.

Pronotum glabrous, lacking pubescence, with large, dense, uneven punctures, denser on sides than on disc, dis- tance between punctures varies, inferior or superior to diameter of punctures, 1.0–1.3 times as wide as long, 1.9–2.3 times as long as head, widest in basal fifth, basal margin straight. Scutellum absent.

Elytra ( Figs 1 A–B) strongly convex, glabrous, widest in basal third, connate, elytral interstriae flat, very broad, with transverse grooves of different length on disc, grooves can connect neighbouring striae, interstriae on apex with large punctures, striae formed by shallow grooves bearing uneven small punctures. Hind wings absent.

Prosternum shagreened, with few shallow punctures, punctures bearing setae, prosternal process narrow, reaching short anterior mesoventral process, isthmus clearly separating fore coxae, mesoventrite and metaventrite on same level, metaventrite about 1.2 times as long as mesoventrite, mesoventrite shagreened, lacking punctures and setae, metaventrite shiny, with sparse, long macrosetae, posterior mesoventral and anterior metaventral processes truncate, meeting on same width, isthmus about as wide as transverse width of mesocoxae; metacoxae widely sepa- rated by large, convex process of first ventrite.

Abdomen shiny, setation of abdomen and metaventrite similar; ventrite 1 about 1.2 times as long as ventrite 2; ventrites 3 and 4 subequal, short, about 0.3 times as long as 2; ventrite 5 about as long as ventrite 1. Legs and male and female terminalia as described for the genus.

Etymology. The name is derived from the Latin, sabulosus , referring to the sandy habitat where all specimens were found.

Biology. The adult beetles were found on the leeward side of the dunes ( Figs 5 A–E) at a depth of 15–30 cm beneath the surface, showing external signs of feeding activity on (“dry”) root parts of Calotropis procera (Aiton) W.T. Aiton ( Fig. 5D ), especially when it had a weak, deviating layer of bark but also under bark, and then even more abundantly in the hollow internal part of the stems, where they may have more moisture. They were never found on the surface of the plant which is always covered by about a 5 mm thick layer of hot and dry sand. All beetles were collected individually by an exhaustor, or by removing the sand with a rupture into a tray and subsequent sieving ( Fig. 5B ).

Distribution: Oman, so far known only from the type locality.

Figures

FIGURE 1. Omanocossonus sabulosus sp. nov., habitus, male, lectotype: A—dorsal view, B—lateral view. Scale bar: 1 mm.

FIGURE 5. Images from in Oman showing habitat of Omanocossonus sabulosus sp. nov.: A—the sand dunes, 6 km NW of Mirbat (seacoast) in Dhofar Gov (Oman); B—Jan Pelikán collecting on the locality; C—the dead (“dry”) root parts of Calotropis procera; D—Calotropis procera (Aiton) W.T. Aiton (Apocynaceae); E—adult beetles were found on the leeward side of the dunes at a depth of 15–30 cm beneath the surface, where they are likely feeding on the outside of the dead (“dry”) root parts. The photos were taken by Jan Pelikán and Tomáš Kopecký.