Omanocossonus 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 : 131-132

Omanocossonus Hlaváč, Skuhrovec & Pelikán gen. nov.

( Figs 1 A–B, 2A–B, 3A–E, 4A–H)

Type species. Omanocossonus sabulosus Hlaváč, Skuhrovec & Pelikán sp. nov., gender masculine.

Etymology. The name is a combination of Oman, the country where the genus was discovered, and Cossonus , referring to the affinity of the genus to the subfamily Cossoninae .

Diagnosis. Rostrum wide, about as long as wide, not delimited from rest of head capsule, eyes well-defined, lateral, distant from posterior margin of pronotum, funicle composed of seven antennomeres, slightly shorter than scape, scape at base pedunculate, last three antennomeres of antennal club completely fused. Humeri absent, elytra on sides rounded, strongly narrowed to apex. Mesoventrite on the same level as metaventrite, mesoventral process much wider than prosternal process, slightly wider than middle tibiae. Terminal tarsomere shorter than tarsomeres I–III combined, claws free, simple.

Description. Body stout, reddish-brown, almost completely glabrous, shiny ( Figs 1 A–B); about 2.9–3.5 mm long.

Head short, about half length of pronotum, rostrum wide, about as long as wide, strongly punctured ( Figs 2 A–B), eyes laterally slightly prominent, temples more than 1.5 times as long as longitudinal diameter of eyes, posterior part of head less densely punctured. Head ventrally shagreened, lacking gula, with gular suture entire on posterior part.

Antennae ( Figs 2A , 3A ) short, inserted in midlength of rostrum, scape longest, basally pedunculate, funicle about as long as scape, with 7 antennomeres; antennomere II longest, III slightly longer than wide, antennomeres IV–VIII transverse, club compact and semi-spherical, composed of last three fused antennomeres, with dense bunch of short setae.

Pronotum more than twice as long as head, almost as wide as long, maximum width in basal fourth, surface with dense, large uneven punctures, anterior and posterior margin straight, slightly constricted just before anterior margin, with few lateral setae.

Elytra oval in dorsal view, about 1.35 times as wide as pronotum and about 1.45 times as long as wide, with 6 shallow striae, interstriae wide, both striae and interstriae bearing shallow, small punctures. Humeri absent.

Venter. Prosternum and mesoventrite on same level, shagreened, both with few shallow discal punctures, pro- sternum with transverse depression close to densely dentate anterior margin, prosternal process narrow, reaching short anterior mesoventral process, procoxae narrowly separated, posterior mesoventral process wide, slightly con- vex, about as wide as width of mesocoxae, attached to anterior slightly concave metaventral process. Metaventrite slightly wider than mesoventrite, with dense shallow punctures, setose, posterior metaventral process wide, straight, about twice as wide as anterior metaventral process, metaventrite and ventrite 1 with median shallow depression.

Abdomen ( Fig. 3B ) with ventrites 1–2 fused, separation line slightly-defined in middle, both shiny, with few shallow punctures and setae, ventrite 1 slightly longer then 2, together very long, clearly longer than ventrites 3–5, ventrites 3 and 4 very short, ventrite 5 almost twice as long as 3–4 combined, with dense setation on posterior margin.

Legs short and stout, protibiae with strongly prolonged uncus, mucro absent ( Fig. 3C ), mesotibiae with premu- cro, uncus about as long as mucro ( Fig. 3D ), metatibiae strongly expanded at apex, uncus shorter than mucro ( Fig. 3E ); terminal tarsomere (onychium) about as long as tarsomeres II and III combined, claws free, simple.

Male terminalia. Sternite IX ( Fig. 4B ) slightly curved anteriad, basal arms well defined, left distinctly longer than right. Tegmen ( Fig. 4D ) short, manubrium shorter than diameter of tegmen ring, parameres absent. Penis ( Figs 4A, D ) short, slightly curved laterally, about 2.5 times shorter than aedeagal apodemes; endophallus with three welldefined sclerites ( Figs 4A, D ).

Female terminalia. Sternite VIII ( Fig. 4E ) asymmetrical, with long and slender apodeme, anterior bar of apodeme very weakly-defined; basal plate wide, bearing short setae, more strongly sclerotized at base. Ovipositor ( Fig. 4F ) sim- ple, small, elongate, weakly sclerotised, styli parallel-sided, truncate at apex, bearing 4 apical setae. Spermatheca ( Fig. 4H ) simple, with regularly curved corpus, cornu tapered, nodulus round, ramus absent. Rectal loop ( Fig. 4G ) long.

Sexual dimorphism. Not apparent.

Differential diagnosis. Omanocossonus gen. nov. belongs to a group of flightless genera of Cossoninae that are characterized by having weakly defined humeri and having the sides of the elytra oval. These palaearcic genera were grouped by Folwaczny (1973) in three weakly defined tribes ( Dryotribini , Neumatorini and Onycholipini ). The monogeneric Neumatorini should be definitely excluded from this group as the elytra of Neumatora Normand, 1920 are clearly parallel-sided, not rounded. Unfortunately, this is also the case for many Dryotribini and Onycho- lipini. Onycholipini differs from Dryotribini by having short rostrum (about as wide as long) while the rostrum is always clearly longer than wide in Dryotribini . Due to the rostrum of Omanocossonus being as wide as long, the best but only tentative position for Omanocossonus is in the tribe Onycholipini . At present, Onycholipini con- tains 21 genera ( Alonso-Zarazaga & Lyal 1999), although the reason for this placement is questionable. At least Hexarthrum Wollaston, 1860 ; Leipommata Wollaston, 1857 ; Pselactus Broun, 1886 ; Pseudopentarthrum Wollaston, 1873 and Tarphius Pascoe, 1885 have the rostrum clearly longer than wide and so they should not be placed into Onycholipini . Thus, Omanocossonus can be readily separated from these genera. Omanocossonus also cannot be confused with genera with parallel-sided, often in cross-section cylindrical body, and which are members of Onycholipini : Beaveriola Osella, 1983 ; Brachytemnus Wollaston, 1973 ; Eurycorynes Wollaston, 1873 ; Hopliturus Marshall, 1956 ; Miorrhinus Marshall, 1936 ; Pseudophloeophagus Wollaston, 1873 ; Pseudostenoscelis Wollaston, 1877 ; Stenoscelis Wollaston, 1861 ; Stenoscelodes Konishi, 1962 ; Stereocorynes Wollaston, 1873 and Trichacorynus Blatchey, 1916 . In fact, Omanocossonus mostly resembles the genus Pentatemnus Wollaston, 1861 and Lindbergius Roudier, 1957 , both actually assigned to Dryotribini by Alonso-Zarazaga & Lyal (1999), but the placement of both of these genera within this tribe is also questionable. It seems that the positions of genera in these two tribes are mixed and both tribes should be probably merged together or else other characters to delimit them should be found. Omanocossonus is readily separated from Pentatemnus by the rostrum being about as long as wide, clearly longer than wide in Pentatemnus and from Lindbergius , by the glabrous elytra lacking tubercles and the normally developed, dorsally well-visible eyes.

Figures

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

FIGURE 2. Omanocossonus sabulosus sp. nov., rostrum, male, lectotype: A—dorsal view, B—lateral view.

FIGURE 3. Omanocossonus sabulosus sp. nov., A—left antenna; B—abdomen; C—protibia and tarsus; D—mesotibia and tarsus; E—metatibia and tarsus. Scale bars: 0.2 mm.

FIGURE 4. Omanocossonus sabulosus sp. nov., male genitalia: A—aedeagus, dorsal and lateral view; B—male sternite 9 (spiculum gastrale); C—aedeagus, upper sclerite, D—tegmen; and female genitals: E—female sternite 8 (spiculum ventrale); F—ovipositor; G—rectal loop; H—spermatheca. Scales bars: 0.2 mm (A–C, D–H), and 0.05 mm (C).