Ceutorhynchus unguicularis, C. G. Thomson, 1871

Korotyaev, B. A., 2020, A review of weevils of the genus Ceutorhynchus (Coleoptera: Curculionidae), associated with woodland draba, Draba nemorosa (Brassicaceae), Zoosystematica Rossica (China) 29 (2), pp. 353-367 : 360-363

Ceutorhynchus unguicularis species group

Diagnosis. Body small, 1.5–2.3 mm long, robust. Dorsal vestiture sparse, rather uniform. Disc of pronotum with sparse very narrow, parallel-sided, truncate apically white or greyish scales, with short broad-lanceolate white scales along base, usually also with sparse scales along median line and along sides; intervals of elytra with sparse similar scales; in addition, with wider white scales along suture and at bases of 1st and 2nd intervals. Elytral striae bare. Underside with moderately dense white lanceolate scales. Antennal funicle seven-segmented, fine; club weakly to strongly elongate, two to four times as long as wide, terete, matte, with very dense short, fine pubescence. Rostrum moderately long, slender, levelling with frons at base, about as wide as fore tibia in middle part, cylindrical, moderately strongly, evenly curved dorsoventrally, rather finely, moderately densely punctate in basal half, sparsely and very finely punctate and moderately to strongly shining in apical one-third to one-half, with rath- er ill-defined low, obtuse median carina in basal part. Antennae inserted near rostrum mid-length. Pronotum weakly to moderately transverse, with weak but noticeable lateral tubercles, moderately convex, rather shining, with medium-sized, moderately dense punctures. Elytra with weakly to moderately prominent humeri and weakly to moderately rounded sides and moderately convex disc; preapical prominences weakly to moderately pronounced, with fine granules not conspicuously condensed and forming no oblique ridges. Elytral striae rather wide and deep, intervals moderately shining, as wide as, or not much wider than striae, flat or slightly convex, shining, with rather sparse punctures and minute granules. Legs moderately long, femora mutic, tarsi moderately long and wide, claws short, weakly diverging, with well visnot more than triple as long as wide

( Figs 9, 27). Elytra often less strongly rounded and with more convex humeri

( Fig. 5). Aedeagus wider, less rounded and wider apically ( Figs 15, 21). Body length 1.5–2.3 mm. South of East Siberia, Central Yakutia ..............

.......... C. sp. [? C. unguicularis ]

3 (2). Antennal club strongly elongate,

3.5–4.2 times as long as wide ( Fig.

26). Elytra more strongly rounded,

with less produced humeri ( Fig. 24).

Aedeagus narrower, more strongly rounded and narrower apically ( Fig.

17). Body length 1.7–2.2 mm. South of Figs 19–23. Ceutorhynchus , aedeagus, dorsal view. 19, C. gemuri- the Russian Far East................ cus, Azerbaijan, Nakhchivan Autonomous Republic; 20, C. kipchak ,.............. C. kerzhneri sp. nov. Buryatia, Nikol’sk Vill.; 21, C. sp. [? C. unguicularis ], Tuva; 22, 4 (1). Disc of pronotum and elytra with C. querceti ; 23, C. cochleariae , Irkutsk. Photo by K.V. Makarov. greyish parallel-sided scales clearly con-

trasting with broad-lanceolate white scales. Elytra wider, with more promiible appendage at base. Fore tibia of male not mu- nent humeri ( Fig. 25). Antennal club moderately cronate, middle and hind tibiae finely mucronate. long, 2.4–2.8 times as long as wide ( Fig. 28). Aedea- Middle tibia of female not mucronate. Aedeagus gus longer and narrower, evenly rounded apically weakly sclerotised, with obtuse-angular apex, oc- ( Figs 16, 25). Body length 2.2–2.3 mm. South of East

Siberia and the Russian Far East (only Primorskiy casionally slightly attenuate at tip.

Terr.), eastern Mongolia...... C. melniki sp. nov. Species included. The group includes C. mohri Dieckmann, 1960 from Spain, C. nigritulus

Ceutorhynchus kerzhneri sp.nov. Schultze, 1897 from Central and Southern Eu-

( Figs 17, 24, 26) rope ( Alonso-Zarazaga et al., 2017), C. unguicularis from Europe and Anatolia, with obscure form Ceutorhynchus unguicularis : Korotyaev, 1980: 160, from southern East Siberia and Central Yakutia , pro parte (specimens from Primorskiy Terr.), nec and two new species from the Eastern Palaearctic C.G. Thompson, 1871 (misidentification). described below. Holotype, female: Russia, Primorskiy Terr., 20 km Comparison. Species of the C. unguicularis W of Spassk-Dal’niy, Lake Khanka shore, meadows group differ from species of the C. cochleariae with Salix stand, 12.VI.1989, S.A. Belokobylskij leg. group ( Korotyaev, 1980) with black elytra and Paratypes. Russia: Primorskiy Terr., Nakhodka legs first of all in the secondary sexual characters, City, waste land, 21.VIII.1959, I.M. Kerzhner leg., namely the non-mucronate middle tibia of female 1 male; Sakhalin Prov., Kunashir I., Sernovodsk Vill.,

16.VII.1973, I.M. Kerzhner leg., 1 female. and apically sclerotised and convexly rounded

Description. The new species is very similar aedeagus, which is always emarginate and poorly

to C. unguicularis and noticeably differs only in sclerotised medially in C. cochleariae , C. dauricus

the much longer antennal club ( Fig. 26) and much and C. ussuricus Korotyaev, 1997 .

narrower and more strongly rounded at sides aedeagus ( Fig. 17). A key to species of the Ceutorhynchus ungui-

Rostrum of male 1.71 times as long as pronocularis group from Siberia and the Far East

tum, that of female, 1.77–1.80 times. 1 (4). Body covered dorsally only with white scales. Antennae of male inserted at 0.48 length of Elytra narrower, with less prominent humeri (Figs rostrum from base, those of female, at 0.46–0.48 5, 24). Antennal club varyingly long. length. Club of female 3.54, of male 4.20 times as 2 (3). Antennal club weakly or moderately elongate, long as wide.

Pronotum of male 1.50, that of female 1.47– 1.50 times as wide as long.

Body length of male 1.65, of female 2.00 (Lake Khanka)–2.15 (Kunashir I.) mm.

Etymology. The species is named after the late I.M. Kerzhner, an outstanding Russian entomologist, who made valuable contribution to the knowledge of the insect fauna of every region he ever investigated.

Distribution. The south of the Russian Far East (Primorskiy Terr. and Kuril Is. – Kunashir).