The present communication continues the series of publications dealing with the weevils of the Sino-Tibetan mountains of China and based on examination of long-term collections of I.A. Belousov, I.I. Kabak, and the author (all from the All-Russian Institute of Plant Protection, St. Petersburg).

MATERIALS AND METHODS

The study is based on examination of the collection of the Zoological Institute, Russian Academy of Sciences (St. Petersburg; ZIN). The beetles were glued onto rectangular cardboard plates; for the dissected specimens, the venter was glued on separately in the back right corner of the same plate, the genitalia and terminalia were placed in the back left corner in a drop of water-soluble fixative.

The following designations are adopted in the text: a process at the apex of the hind tibia of the male is a process at the place of the mucro on the hind tibia of the male; the penis tube is a tubular part of the penis from the lamella of the penis to the apophyses (apophyses = apodemes); the ostial plate is a sclerotized apical plate on the dorsal side of the preapical part, covering the ostium; the ventral plate of the penis (pedon) is a sclerotized plate forming the ventral wall of the penis.

The length of the process of the inner apical angle of the male hind tibia was measured from the place of attachment of the tarsus to the apex of the process; the lengths of the penis, penis tube, and lamella of penis were measured directly from the place of attachment of the apophyses to the apex of the aedeagus, from the place of attachment of the apophyses to the distal margin of the ostium, and from the distal margin of the ostium to the apex of the aedeagus, respectively.

The photographs of the genitalia and terminalia were taken from the slides in glycerol by means of an Axio Imager M-1 Carl Zeiss microscope in the Laboratory of Biomethod of the All-Russian Institute of Plant Protection. All the holotypes are deposited in the collection of the Zoological Institute, Russian Academy of Sciences (St. Petersburg, ZIN). Part of the paratypes will be granted to the collection of Institute of Zoology, Chinese Academy of Science (IZCAS, Beijing) and Senckenberg Naturhistorische Sammlungen (MTD, Dresden, Germany).

Subfamily ENTIMINAE Schoenherr, 1823

Tribe Blosyrini Lacordaire, 1863

The tribe is characterized by a great morphological diversity and by a vague diagnostics of its genera. The tribe includes the following genera distributed in Africa and Asia: Blosyrus Schoenherr, 1823, Blosyrodes Jekel, 1875, Dactylotus Schoenherr, 1847, Trachyphloeoides Formánek, 1907, Proscephaladeres Schoenherr, 1840, Bradybamon Marshall, 1919, and Holonychus Schoenherr, 1840; the first five genera are listed in the Catalogue of Palaearctic Coleoptera Curculionoidea (Alonso-Zarazaga et al., 2017). The record of the African genus Proscephaladeres (the type species P. punctifrons Boheman, 1840) from northern India (Ganghi and Pajni, 1984) is erroneous because of misidentification of P. kashmirienensis Ganghi et Pajni, 1984 and P. pubescens (Marshall, 1916). The morphological characters of these species do not correspond to the diagnosis of Proscephaladeres, according to which the outer surface of the mandible is covered with pale elongate scales, and the basal margin of the elytra is unbordered and smoothly beveled toward the mesothoracic articular ring (Marshall, 1919; Emden, 1936). Therefore, the initial combination Blosyrodes pubescens Marshall, 1916 is resurrected here; apparently, P. kashmirienensis, should also be referred to the same genus.

An attempt to classify Blosyrini was undertaken by B.A. Korotyaev (1996) with respect to the genus Dactylotus Schoenherr, 1847 similar to Blosyrus. Four subgenera were distinguished in the genus: Dactylotus, Kamius Korotyaev, 1996, Dactylotinus Korotyaev, 1996, and Nipponoblosyrus Korotyaev, 1996. Nipponoblosyrus had been reduced to synonyms of Blosyrus without an adequate substantiation (Morimoto et al., 2015; Alonso-Zarazaga et al., 2017), but was subsequently fairly resurrected by V.Yu. Savitsky (2020) as a subgenus of Dactylotus. From my point of view, the closely related genera Blosyrus, Blosyrodes, and Dactylotus constitute a complex of the genus group taxa with the classification somewhat reminding that of the Palaearctic genus Otiorhynchus Germar, 1822 comprising over 100 subgenera (Davidian and Savitsky, 2006).

Short diagnosis (after Marshall, 1916 and Morimoto in: Morimoto et al., 2015). Rostrum dorsally nearly as long as wide, separated from head by transverse sulcus; eyes convex, distinctly projecting beyond lateral contour of head; antennal scrobes lateral; prementum entirely concealing mouthparts; wings rudimentary; corbel on hind tibia open; claws connate in basal part; suture between two basal ventrites rather deep and nearly straight; ventrites II–IV subequal in length, or ventrite II slightly longer. Male genitalia with remarkable variety of endophallus armament. Structure of female genitalia rather uniform: gonocoxites separate, each with stylus at apex; lamella of spiculum ventrale in the form of triangular plate; spermatheca usually with rather long collum and ramus; cornu wide and short.

The larva is soil-dwelling. Polyploid parthenogenesis was found in Dactylotus angusticollis (Motschulsky, 1866) (= Blosyrus falcatus Faust, 1882; = B. japonicus Sharp, 1896); its bisexual form differs in a smaller body (Takenouchi, 1976). The synonymy is given after V.Yu. Savitsky (2020).

Note. The statement that the true wings in Blosyrini are reduced (Morimoto et al., 2015) does not apply to all of them: in the widely distributed Blosyrus asellus (Olivier, 1807), 2 examined specimens from Vietnam and Borneo Island (= Kalimantan) have turned out to be apterous, and the beetle from Yunnan Province of China had well-developed wings.

Genus BLOSYRUS Schoenherr, 1823

Type species Curculio oniscus Olivier, 1807, by original designation.

Blosyrinus Jekel, 1875 (type species Blosyrus inaequalis Boheman, 1845).

Maes Fairmaire, 1888 (type species Maes transversicollis Fairmaire, 1888).

Blosyridius Fairmaire, 1891 (type species Blosyridius vestitus Fairmaire, 1891).

The synonymy is given according to the Catalogue of Palaearctic Coleoptera Curculionoidea (Alonso-Zarazaga et al., 2017). The genus Blosyrus comprises 101 species, among which 92 inhabit Africa to the south of Sahara, and the others occur in Asia (Mahendiran and Ramamurthy, 2013).

Blosyrus oniscus (Olivier, 1807)

Material. Myanmar: Bhamo, 1 ♂; Pegu, 1 ♀.

Description. Rostrum transverse, subrectangular, 1.2 times as long as longitudinal diameter of eye. Rostral dorsum equal in width to rostrum; antennal scrobes lateral, not visible in dorsal view, slightly curved dorsoventrally, not extending onto ventral side of rostrum, terminating below anterior part of eye and separated from it by narrow raised stripe. Antennae rather short; scape at rest considerably not reaching posterior margin of eye, its length 0.53 times width of rostrum at antennal insertion. Eyes very convex; head at level of eyes 1.67 times as wide as frons.

Pronotum weakly transverse, widest distal to midlength, 1.29 times as wide as long, slightly compressed laterally in basal half, with round shining granules on disc. Pronotal disc distinctly raised above mesothoracic articular ring; posterior margin of pronotum convex in sagittal section. Scutellum rounded, convex, lying in one plane with elytral disc.

Elytra oval, longitudinally and transversely convex; striae formed by large deep punctures, slightly wider than interstriae. Elytral interstriae uniform, with slightly confused row of round shining granules similar to those on pronotum; 5th and 7th interstriae with small tubercles.

Fore femur flattened or slightly depressed ventrally in middle part. All tibiae with similar dentiform mucro; external margin of apical comb of hind tibia bent inwards; 2nd segment of hind tarsus transverse. Venter 2.94 times as wide as intercoxal process of ventrite I. Ventrite V of male strongly obtused, with deep longitudinal depression behind basal 1/3.

Aedeagus flattened; penis slightly transverse, noticeably shorter than apophyses, with wide ostial plate dorsally; apical margins of penis and ostial plate widely rounded.

Integument of body with rather dense pale vestiture of recumbent rounded, weakly elongate scales; antennae and tarsi with distinct narrow scales. Posteriobasal margin of pronotum with distinct recumbent scales. Elytra dorsally with 8–12 small white spots situated symmetrically on 3rd–5th and 7th interstriae.

Comparative diagnosis. Blosyrus oniscus is most closely related to B. herthus (Herbst, 1797) but clearly differs in the presence of small white spots on the elytra.

Biology. According to the literature, the Asian species B. asellus, B. oniscus, and B. unisulcatus Marshall, 1916 occur on grasses and bushes (Gandhi and Pajni, 1984), while B. inaequalis Boheman, 1845 is mentioned as a pest of beniseed (Sesamum sp.) and beans (Vicia sp.) (Marshall, 1916). In Africa, B. batatae Marshall, 1927 damages Ipomoea batatas (L.) Lam. (Marshall, 1927).

Taxonomic notes. The results of examination of some African and Asian species of Blosyrus suggest that the African genus Blosyridius was unreasonably reduced to synonyms of Blosyrus (Emden and Emden, 1939). The type species Blosyridius vestitus is known to me from Haaf’s (1958) publication containing a drawing of the apical part of its aedeagus. The differences between Blosyrus and Blosyridius are listed here in the key below.

Antennal scrobes not extending onto ventral side of rostrum, usually separated from lower margin of eyes by narrow convex area. Lower margin of antennal scrobe smoothly lowering toward base of rostrum. Penis with more or less wide ostial plate rounded or emarginate apically, usually without projecting sclerites outside ostium. Ventral plate of penis (pedon) projecting beyond base of apophyses ........ Blosyrus.

—Antennal scrobes slightly extending onto ventral side of rostrum and usually reaching lower margin of eye. Lower margin of antennal scrobe angularly raised before base of rostrum. Penis without ostial plate, with rather large sclerites outside ostium. Ventral plate of penis (pedon) not projecting beyond base of apophyses ........ Blosyridius.

It is not yet possible to discuss the composition of these genera without a revision of the majority of the Asian and African Blosyrus. Among the taxa known to me from the literature, B. obliquatus Duvivier, 1892, as well as the species closely related to it in Haaf’s (1958) opinion, may also belong to Blosyridius. At the same time, the structure of the penis in some African species of Blosyrus (B. saevus Boheman, 1840) is similar to that in the Asian taxa.

Genus BLOSYRODES Jekel, 1875

Type species Blosyrodes quadrinodosus Jekel, 1875, by original designation.

The type species of the genus is known to me from the literature. It is widely distributed in Pakistan, in the north of India, and in the Oriental Region (Alonso-Zarazaga et al., 2017). Blosyrus depressus Faust, 1886 described from 2 specimens with the geographical label “Murree et Sind Valley” [state of Punjab in the northeast of Pakistan, district of Rawalpindi (Punjab, Rawalpindi)] was reduced to its synonyms. The habitus and the genitalia of both sexes of B. quadrinodosus were illustrated in Mahendiran’s publication (2009). According to this author, the genus Blosyrodes comprises only 12 species: 8 in India, 2 in China, 1 in Myanmar, and 1 in Indonesia.

Biology. The data on the biology of weevils of the genus Blosyrodes are extremely poor and confined to the comment that the beetles occur on soil, under rocks, and on wild-growing vegetation (Gandhi and Pajni, 1984).

Taxonomic notes. The weevils of the genus Blosyrodes are most closely related to those of the genus Dactylotus and to the Asian representatives of the genus Blosyrus. All the species have the penis with an ostial plate and with its ventral plate considerably projecting between the apophyses. The armament of the endophallus varies; it is usually formed by large sclerotized plates, teeth, and chords and rarely by punctiform sclerites on the walls of the sac.

Discussion of the diagnosis of the genus Dactylotus is beyond the framework of this study. The most complete morphological description of the genus was given by B.A. Korotyaev (1996) and supplemented by V.Yu. Savitsky’s (2020) publication including interesting comparative morphological analysis of Blosyrus and Dactylotus.

The comparative diagnostics of the genera Blosyrus and Blosyrodes is given here in the form of a key based on the key of Marshall (1916) who noted that the existing keys did not allow exact identification of the generic belonging of some species.

Frons usually with 3 wide deep longitudinal depressions. Rostrum usually distinctly transverse, subrectangular. Rostral dorsum entirely concealing antennal scrobes in dorsal view. Antennae short; width of rostrum at antennal insertion 1.75–1.89 times length of antennal scape; scape at rest considerably not reaching posterior margin of eye; 2nd funicular segment usually shorter than, or as long as 1st one. Pronotum less transverse, 1.29–1.31 times as wide as long, with basal margin distinctly raised above mesothoracic articular ring, with distinct recumbent scales on convex posterior surface. Scutellum convex, rounded apically. Legs thickened; external margin of apical comb of hind tibia bent inwards. Antennae and tarsi with distinct elongate scales ........ Blosyrus.

—Frons usually with distinct narrow median sulcus and with wide lateral depressions near eyes. Rostrum less transverse, usually narrowed from base, occasionally widened in apical part. Antennal scrobes clearly visible in dorsal view. Antennae rather long; length of antennal scape subequal to width of rostrum at antennal insertion; scape at rest usually reaching posterior margin of eye; 2nd funicular segment longer than, but rarely as long as 1st one. Pronotum more transverse, usually 1.32–1.57 times as wide as long, with basal margin slightly raised above mesothoracic articular ring, without scales on posterior surface. Scutellum flat, triangular. Legs slender; external margin of apical comb of hind tibia not bent inwards, directed distad. Antennae and tarsi with hair-like vestiture ........ Blosyrodes.

Genus STILTOBLOSYRUS Davidian, gen. n.

Type species Stiltoblosyrus belousovi Davidian, sp. n.

Description. Male. Beetles medium-sized or large (6.2–10.0 mm), black or dark brown; antennal scape and flagellum and claw-segment of tarsi reddish. Rostrum slightly transverse, rarely nearly as long as wide; its length twice longitudinal diameter of eye; lateral margins noticeably converging from base or running in parallel in apical half. Rostral dorsum clearly narrower than rostrum, usually compressed laterally in middle part, parallel-sided in apical half, occasionally with lateral margins rectilinearly converging from base. Epistome posteriorly margined with glabrous shining black stripe; epistomal carina curved nearly at right angle. Smoothened converging carinae extending from antennal insertion to medial 1/3 of frons. Antennal scrobes lateral, clearly visible in dorsal view, slightly downcurved, not extending onto ventral side of rostrum, terminating below eyes and narrowly separated from them. Eyes dorsolateral, round, usually nearly hemispherical, most convex slightly behind middle; head at level of eyes 1.36–1.69 times as wide as frons. Frons separated from rostral dorsum by distinct transverse sulcus deepest in middle part; narrow median sulcus usually originating from it and extending onto vertex. Lateral areas of frons along eyes more or less raised, separated from middle part by longitudinal depressions. Antennal scape slender, claviform thickened in apical 1/4, at rest nearly reaching posterior margin of eye; 2nd funicular segment slightly narrower and usually longer than 1st segment, rarely as long as it; 3rd–7th segments round or weakly elongate; 7th segment usually wider than others; club fusiform, widest at midlength.

Pronotum distinctly transverse, without postocular lobes, strongly convex laterally, usually widest distal to middle, rather strongly narrowed toward base, with tubercles and small granules on disc, usually with smoothened median callus-shaped carina, or occasionally with fine sulcus.

Scutellum flat, in the form of small triangle.

Elytral disc usually flattened; basal margin clearly, almost cariniform convex, considerably raised above mesothoracic articular ring; apical declivity convex, weakly deflexed or steeply sloping. Humeri slanting, rarely slightly rounded; tubercle at base of 5th interstria usually not projecting beyond contour of humeri. Striae distinct, subequal in width to sutural interstria, and clearly narrower than other interstriae. Intervals between punctures in elytral striae with small shining granule, considerably smaller than punctures. Sutural and even-numbered elytral interstriae flat, without large tubercles, with row of small granules similar to those on pronotum; 3rd, 5th, and 7th elytral interstriae usually with rows of rather large, occasionally conical tubercles, considerably widened in the area of largest tubercles. Large tubercles forming transverse row before apical elytral declivity; similar large tubercle present at apex of 5th interstria. Granules dorsally each with single setiferous puncture; tubercles with several setiferous punctures. Hind wings absent.

Fore coxae contiguous, situated slightly closer to anterior margin of prothorax; middle coxae separated by narrow intercoxal process of mesothorax; hind coxae slightly not reaching lateral margin of elytra, distance between them subequal to width of coxa. Legs slender, rather long. Femora ventrally convex, without tooth; inner margins of tibiae with pointed thickened setae and with distinct granules occasionally in the form of slanting spines. Fore and middle tibiae with spiniform mucro; inner apical angle of hind tibia with more or less strongly elongate process. Apical comb of hind tibia directed distad, not bent downward. Tarsi with sole brushes; 2nd segment of hind tarsus elongate; 3rd bilobed; claw-segment long, widest in apical part, projecting far beyond apical margin of 3rd segment; claws connate in basal 1/3–1/2.

Venter nearly as long as wide. Apical margin of ventrite I slightly rounded in medial 1/3; ventrites II–IV subequal in length.

Aedeagus rather short, flattened dorsoventrally; tegmen without parameroid lobes. Penis flat, weakly elongate, wider than long or as long as wide. Lamella of penis widely rounded or obtused apically, with median apical emargination, occasionally subulate. Dorsal plate of penis membranous; ventral plate noticeably sclerotized, usually considerably projecting between apophyses. Ostial plate usually not projecting beyond contour of penis, with rounded apex. Armament of endophallus formed by numerous minute spicules, usually without larger sclerites.

Vestiture not concealing integument, formed by recumbent, usually narrow, occasionally wide, lanceolate, brown, yellow, or gray scales usually with golden sheen and by similar subrecumbent hairs most clearly visible on tubercles and on apical elytral declivity. Paler scales usually forming 2 ill-defined longitudinal stripes at sides of pronotal disc, transverse band before apical elytral declivity, and also weak transverse band in widest part of femora and before apices of tibiae. Mandibles laterally, antennae, and tarsi with hair-like vestiture, without scales.

Female. All tibiae with similar spiniform mucro. Lamella of spiculum ventrale triangular, distinctly shorter than manubrium, with hairs along apical margin in medial 1/3 (Fig. 5, 19). Spermatheca with rather short thick cornu and with usually longer ramus and collum (Fig. 5, 20). Coxites conical, with elongate stylus apically; vagina with narrow and long, weakly sclerotized plate (Fig. 5, 18).

Comparative diagnosis. The new genus is most closely related to Blosyrodes and differs as follows: the sculpture of the pronotal disc is tuberculate; the 3rd, 5th, and 7th elytral interstriae bear rows of distinct, usually large tubercles; the legs are slender and long; the inner apical angle of the male hind tibia bears a process (occasionally appearing as a very long appendage) at the place of the mucro; the vestiture does not conceal the integument of the body, consists of recumbent, usually narrow, occasionally wide lanceolate scales with golden sheen; the armament of the endophallus is formed by minute spicules, usually without larger sclerites.

Taxonomic notes. A similar structure of the hind tibia of the male is known to me from the literature for Blosyrus marshalli Mahendrian, 2009 from India (Andhra Pradesh, Maharashtra).

Biology. All the species are bisexual. The larva is unknown. The immature development apparently proceeds in soil. Based on my supervision, in the daytime, the adults of the genus Stiltoblosyrus gen. n. usually hide in the forest litter, and at nightfall, they rise onto trees and bushes mainly of the genus Rhododendron L. (family Ericaceae). Some individuals were also collected in the underbrush of currant (Ribes sp.) and irises (Iris sp.). The beetles feed on leaves, making characteristic excavations of the edges of a leaf (Fig. 7, 2), and copulate in the same place. The majority of the weevils were collected at night by beating rhododendron branches, far fewer specimens were collected by sifting the forest litter in the daytime. This is the first record of the weevils of the tribe Blosyrini on rhododendron.

Etymology. The name of the new genus is a masculine noun in apposition formed by the English noun “a stilt” and the name of the related genus Blosyrus.

Distribution. Most of the species of the new genus are distributed in Yunnan, and only one is known from the south of Sichuan. They mainly occur in the upper forest belt and also in the lower alpine belt in rhododendron thickets.

Stiltoblosyrus belousovi Davidian, sp. n. (Fig. 1, 1; Fig. 5, 1, 18–20)

Material. Holotype: ♂, China, Yunnan Prov., NE of Lanping City, 0.95 km NNE of Mt. Xuebangshan, 26°29ʹ14ʺN, 99°30ʹ08ʺE, H = 4035 m, 29.V.2015 (G.E. Davidian). Paratypes: 55 ♂, 12 ♀, as holotype; same locality, 7.4 km WSW of Guanping Vill., 26°30ʹ12ʺN, 99°30ʹ15ʺE, H = 4005 m, 29.V.2015 (G.E. Davidian), 18 ♂, 6 ♀.

Description. Male. Rostrum 1.25 times as wide as long, slightly compressed laterally, subparallel-sided in apical half or weakly narrowed toward apex. Head at level of eyes 1.42 times as wide as frons. Length of antennal scape slightly exceeding width of rostrum at antennal insertion; 1st funicular segment 2.2 times as long as wide, 0.79 times as long as 2nd segment; 2nd segment 2.75–3.0 times as long as wide and 2.33 times as long as 3rd segment; 3rd–6th segments slightly elongate; 7th segment 1.23 times as long as wide, 1.3 times as wide as 1st segment; club fusiform, 2.09 times as long as wide.

Fig. 1.
figure 1

Stiltoblosyrus gen. n., male [(1, 4) paratype; (2, 3) holotype]: (1) S. belousovi sp. n., (2) S. fairmairei sp. n., (3) S. vulgaris sp. n., (4) S. pulcher sp. n.

Full size image

Pronotum 1.34 times as wide as long, widest slightly distal to midlength, with transverse constriction before basal margin.

Elytra oblong-oval, 1.38 times as long as wide, slightly convex laterally (subparallel-sided) in middle part. Large tubercle at base of 5th interstria slightly projecting beyond contour of humeri; in apical part of elytra, largest tubercles situated before apical declivity on 3rd, 5th, and 7th interstriae, and 1 tubercle, at apex of 5th interstria.

Fore tibia smoothly incurved in apical 1/3, with row of slanting spines along inner margin. Hind tibia nearly straight; its inner margin with distinct granules some of which spiniform. Process of inner apical angle of hind tibia pointed, undulate along ventral margin, bent outward in basal part, equal in length to 2nd segment of hind tarsus and noticeably shorter than 1st segment. 2nd segment of fore tarsus as long as wide; 1st segment of hind tarsus 2.09 times as long as wide, 1.33 times as long as 2nd segment; 2nd and 3rd segments equal in length.

Venter slightly longer than wide, 2.23 times as wide as intercoxal process of ventrite I. Ventrite I flat; ventrite V rounded apically, with wide superficial median apicaly depression.

Apophyses of aedeagus as long as penis; penis 2.3–2.5 times as long as wide, weakly narrowed from base to lamella; ventral plate of penis slightly projecting between apophyses. Lamella of penis triangular, narrowly rounded apically; ostial plate angularly emarginate basally, longer than lamella, slightly projecting beyond contour of penis.

Body dorsally and laterally with uniform vestiture formed by similar lanceolate copper-colored scales with metallic sheen, usually without transverse band before apical elytral declivity. Process at apex of hind tibia with row of arcuately curved hairs dorsally.

Body length 6.7–7.9 mm, width 3.3–3.8 mm; those in holotype 7.3 and 3.4 mm, respectively.

Female. Elytra widely oval, 1.17 times as long as wide. Humeri slightly rounded, with large tubercle on 7th interstria. Fore tibia slightly incurved in apical part; hind tibia straight. Venter 2.35 times as wide as intercoxal process of ventrite I; ventrite I clearly convex; ventrite V slightly convex.

Body length 7.2–8.0 mm, width 3.7–4.2 mm.

Comparative diagnosis. Stiltoblosyrus belousovi differs from most of the congeners in the process of the inner apical angle of the male hind tibia which is equal in length to the 2nd, and noticeably shorter than the 1st segment of the hind tarsus. It differs from S. pulcher sp. n. and S. fairmairei sp. n. with a similar structure of the process in the following characters: the elytra are more elongate, 1.38 times as long as wide; the large tubercle at the base of the 5th interstria projects slightly beyond the contour of the humeri; the process of the male hind tibia is pointed apically; the vestiture is usually uniform, that on the pronotum and elytra is formed by uniform, narrowly lanceolate scales; the transverse band before the apical elytral declivity is usually missing.

Biology. The insects were collected at night by beating branches of treelike rhododendron with white flowers and in the afternoon, by sifting the forest litter under the same rhododendron species.

Etymology. The name of the new species is noun in genitive, invariable; the species is named after I.A. Belousov .

Stiltoblosyrus fairmairei Davidian, sp. n. (Fig. 1, 2; Fig. 5, 8)

Material. Holotype: ♂, China, Yunnan Prov., NNE of Wexi City, right tributary of Lapugou River, 5.2 km ENE of Jizong, 27°27ʹ36ʺN, 99°23ʹ53ʺE, H = 3480 m, 5.VI.2015 (G.E. Davidian). Paratypes: 5 ♂, 1 ♀, as holotype.

Description. Male. Rostrum clearly narrowed toward apex, 1.26 times as long as wide. Rostral dorsum compressed laterally in middle, with lateral margins slightly rounded in apical half. Head at level of eyes 1.44–1.50 times as wide as frons. Length of antennal scape subequal to width of rostrum at antennal insertion; 1st funicular antennal segment 2.44 times as long as wide, wider and shorter than 2nd segment; 2nd segment twice as long as wide; 3rd and 4th segments weakly elongate; 5–7th slightly elongate; 7th segment widest, 1.11 times as wide as 1st segment. Club of antenna fusiform, widest slightly distal to midlength, twice as long as wide; sides straight or slightly convex in basal half.

Pronotum widest distal to midlength, 1.43–1.46 times as wide as long, slightly compressed laterally in basal 1/3, with dense granules and tubercles on disc.

Elytra 1.15 times as long as wide, parallel-sided in middle part; large tubercle at base of 5th interstria not projecting beyond contour of slanting humeri. Humeri with large, occasionally conical tubercle on 7th interstria. Largest tubercles in apical part of elytra before apical declivity present on 3rd, 5th, and 7th interstriae, and 1 tubercle, at apex of 5th interstria. Distance between 2 large tubercles in apical part of 5th interstria noticeably shorter than that between last of them and small tubercle at place of merging of 3rd and 9th interstriae.

Fore tibia distinctly incurved in apical part, with slightly concave outer margin. Process of inner apical angle of hind tibia obtused or obliquely truncate, deeply emarginate on outer side at place of its attachment to tibia, as long as, or slightly shorter than 1st segment of hind tarsus, 1.34 times as long as 2nd segment. 2nd segment of fore tarsus 1.11 times as long as wide; 1st segment of hind tarsus 1.78 times as long as wide; 2nd segment 1.41 times as long as wide and equal in length to 3rd segment.

Venter slightly wider than long, 2.33 times as wide as intercoxal process of ventrite I; ventrite I slightly depressed; ventrite V rounded apically, with distinct rounded median depression.

Apophyses of aedeagus 1.92–1.96 times as long as penis; penis 1.4 times as long as wide. Lamella of penis 1.7 times as wide as long, convex laterally, obtused apically, with median emargination; ostial plate horseshoe-shaped, not projecting beyond contour of penis.

Vestiture copper-colored with matte sheen. Pronotum with recumbent lanceolate scales nearly half as wide as those on elytra. Scales on elytra 3–4 times as long as wide, equal in width to, or slightly narrower than setae in elytral striae. Obliquely erect, pointed setiform hairs on elytral interstriae 1.5–2.5 times as long as scales, most distinct on tubercles and on apical elytral declivity.

Body length 6.2–7.0 mm, width 3.5–4.0 mm; those in holotype 6.5 mm and 3.5 mm, respectively.

Female. Pronotum 1.45 times as wide as long. Elytra shortly oval, parallel-sided in middle part, 1.13 times as long as wide. Fore tibia straight, slightly incurved in apical part; 2nd segment of fore tarsus in form of equilateral triangle; 2nd segment of hind tarsus 1.2 times as long as wide. Venter slightly transverse, 2.27 times as wide as intercoxal process of ventrite I; ventrite I convex; ventrite V triangular, 1.61 times as wide as long.

Body length 6.2 mm, width 3.7 mm.

Comparative diagnosis. Stiltoblosyrus fairmairei differs from most of the congeners in an obtused process of the inner apical angle of the hind tibia of the male: it is deeply emarginate on the outer side at the place of its attachment to the tibia, equal in length to the 1st segment of the hind tarsus, and 1.34 times as long as the 2nd segment. The new species is most closely related to S. pulcher sp. n. but differs as follows: the elytra are parallel-sided in the middle part; the slanting humeri bear a large tubercle on the 7th interstria; the process at the apex of the male hind tibia is shorter; ventrite I is slightly depressed; the apophyses of the aedeagus are 1.92–1.96 times as long as the penis.

Etymology. The new species is named after the well-known French coleopterologist L.M.H. Fairmaire who contributed significantly to the study of weevils of China; it is a noun in genitive, invariable.

Stiltoblosyrus pulcher Davidian, sp. n. (Fig. 1, 4; Fig. 5, 9)

Material. Holotype: ♂, China, Yunnan Prov., NE of Liming City, 4.2 km S of Muzhengdu, 27°06ʹ34ʺN, 99°45ʹ03ʺE, H = 3695 m, 3.VI.2016 (G.E. Davidian). Paratypes: 6 ♂, 5 ♀, as holotype.

Description. Male. Rostrum weakly narrowed toward apex, 1.2 times as wide as long. Rostral dorsum clearly compressed laterally, parallel-sided in apical half or slightly widened distally. Eyes hemispherical, most convex slightly behind middle; head at level of eyes 1.53 times as wide as frons. Length of antennal scape slightly exceeding width of rostrum at antennal insertion; 1st funicular antennal segment 2.13 times as long as wide; 2nd segment 3.51 times as long as wide, 1.3 times as long as 1st segment; 3rd–6th segments subequal in length, 1.6 times as long as wide; 7th widest, 1.22 times as long as wide. Club of antenna fusiform, widest at midlength, 2.48 times as long as wide, with lateral margins straight in basal half.

Pronotum transverse, widest distal to midlength, 1.37–1.50 times as wide as long, slightly compressed laterally in basal 1/3, with dense granules and tubercles on disc.

Elytra shortly oval, slightly convex laterally, 1.23 times as long as wide; humeri straightly slanting, with moderately convex, smoothened tubercle on 7th interstria; tubercle at base of 5th interstria not projecting beyond contour of humeri; largest tubercles in apical part of elytra before apical declivity present on 3rd, 5th, and 7th interstriae, 1 tubercle, at apex of 5th interstria. Distance between 2 large tubercles in apical part of 5th interstria noticeably shorter than that between last of them and small tubercle at place of merging of 3rd and 9th interstriae. Sutural and even-numbered elytral interstriae with sparse granules similar in size to the smallest granules on pronotum.

Fore tibia straight, incurved in apical 1/3; its inner margin with granules spiniform in apical half. Hind tibia straight, with distinct granules on inner margin; process at apex of tibia slightly S-curved, straight along ventral margin, obliquely truncate and slightly rounded apically, deeply emarginate on outer side at place of its attachment to tibia, 1.02–1.19 times as long as 1st segment of hind tarsus, 1.65–1.76 times as long as 2nd segment. 2nd segment of fore tarsus 1.22 times as long as wide, slightly shorter than 3rd; 1st segment of hind tarsus 2.33 times as long as wide, 1.43 times as long as 2nd one; 2nd segment 1.65 times as long as wide, slightly longer than 3rd.

Venter as long as wide, 2.36 times as wide as intercoxal process of ventrite I; ventrite I clearly depressed; ventrite V rounded apically, with superficial median depression.

Aedeagus long; apophyses 2.4–2.85 times as long as penis. Penis slightly elongate, parallel-sided in basal part, 1.17–1.39 times as long as wide. Lamella of penis widely triangular, obtused at apex, with median emargination, 2.37 times as wide as long; ostial plate slightly longer than lamella, slightly projecting beyond its contour.

Dorsal side with lanceolate recumbent scales; those on elytra 1.3–2 times as wide as those on pronotum. Setiform hairs on elytral interstriae longer than scales, clearly raised, most distinct on tubercles. Vestiture on lateral surface of elytra sparser than that on disc. Dorsal side of process at apex of hind tibia with subrecumbent hairs.

Body length 6.3–7.1 mm, width 3.4–4.0 mm; those in holotype 6.7 and 3.6 mm, respectively.

Female. Pronotum 1.42 times as wide as long. Elytra 1.16 times as long as wide. Fore tibia slightly incurved in preapical part; hind tibia straight. Ventrite I distinctly, and ventrite V slightly convex. In one of three dissected females, coxites without styli.

Body length 6.4–7.2 mm, width 3.8–4.2 mm.

Comparative diagnosis. Stiltoblosyrus pulcher differs from most of the congeners in an obtused process of the inner apical angle of the hind tibia of the male: it is deeply emarginate on the outer side at the place of its attachment to the tibia, slightly longer than the 1st segment of the hind tarsus and noticeably longer than the 2nd segment. The new species also differs from S. belousovi sp. n. in less elongate elytra, in the tubercle at the base of the 5th elytral interstria not projecting beyond the contour of the elytra, in the scales on the elytra 1.3– 2 times as wide as those on the pronotum. It is most closely related to S. fairmairei sp. n. but differs as follows: the elytra are slightly convex laterally, the humeri bear a weak convex tubercle on the 7th interstria, the process at the apex of the male hind tibia is longer, ventrite I is clearly depressed, and the apophyses are 2.40–2.85 times as long as the penis.

Biology. The insects were collected at night, most likely from iris.

Etymology. The name of the new species is the Latin masculine adjective “pulcher” (nice).

Distribution. The new species occurs together with S. kabaki sp. n. and S. titanicus sp. n.

Stiltoblosyrus vulgaris Davidian, sp. n. (Fig. 1, 3; Fig. 5, 4)

Material. Holotype: ♂, China, Sichuan Prov., W of Pingchuan Town, from 27°40ʹ07ʺN, 101°44ʹ04ʺE to 27°38ʹ02ʺN, 101°44ʹ34ʺE, 3735–3800 m, 18.VII.2011 (I.A. Belousov, I.I. Kabak).

In the holotype, the 5–7th funicular segments and club of the left antenna, the claw-segments of the fore and hind left tarsi, and also the 3rd and claw-segments of the middle left tarsus have been lost.

Description. Male. Rostrum parallel-sided in apical half, 1.33 times as wide as long. Rostral dorsum clearly compressed laterally in middle, with fine median carina distinctly widened toward strongly raised epistomal carina. Eyes hemispherical, most convex slightly behind middle; head at level of eyes 1.36 times as wide as frons. Frons slightly convex, with rather deep longitudinal sulcus extending onto vertex. Width of rostrum at antennal insertion 1.24 times length of antennal scape. 1st funicular antennal segment slightly wider than 2nd segment; 2nd segment 2.68 times as long as wide, 1.2 times as long as 1st segment; 3rd–6th segments subequal in length, 1.33 times as long as wide, half as long as 2nd segment; 7th segment widest, 1.33 times as long as wide. Club of antenna fusiform, widest at midlength, 2.27 times as long as wide, slightly convex laterally in basal half.

Pronotum widest distal to midlength, 1.48 times as wide as long, clearly compressed laterally before base; disc with numerous small granules and with median carina in middle part.

Elytra widely oval, with straight basal margin, 1.15 times as long as wide; disc slightly tuberculate, with most distinct tubercles on 5th and 7th interstriae and with rows of similarly small granules more smoothened than those on pronotum.

Legs slender and long; tibiae straight. Fore tibia 2.53 times as long as antennal scape, with small granules on inner margin and with straight rounded outer apical angle. Process of inner apical angle of hind tibia slightly shorter than 2nd segment of hind tarsus, with short tooth ventrally before obtused apex. 2nd segment of fore tarsus in the form of equilateral triangle, shorter than 3rd segment; 1st segment of hind tarsus twice as long as wide; 2nd as long as wide, shorter than 3rd segment.

Venter slightly longer than wide, 2.52 times as wide as intercoxal process of ventrite I; ventrite I with superficial depression; ventrite II 1.46 times as long as ventrite III; ventrites III and IV equal in length; ventrite V 1.76 times as wide as long, with distinct median depression, with shallow median emargination apically, with weak cariniform margination laterally.

Aedeagus short and wide; apophyses 2.4 times as long as penis. Penis 1.7 times as long as wide; lamella of penis widely triangular, obtused apically, longer than penis tube; ostial plate widely rounded apically, slightly projecting beyond lateral contour of penis. Armament of endophallus formed by numerous punctiform granules in middle part, with 2 larger sclerites in area of aggonoporium.

Vestiture of body yellowish gray, without metallic sheen, formed by recumbent scales and by longer raised pointed setiform hairs. Scales on elytra obtused, their length 0.33–0.50 times diameter of punctures in striae; scales on pronotum slightly narrower and longer. Lateral surface of pronotum and elytra with sparse vestiture; 8th and 9th elytral interstriae nearly glabrous.

Body length of holotype 7.3 mm, width 4.03 mm.

Female unknown.

Comparative diagnosis. Stiltoblosyrus vulgaris clearly differs from all the congeners in a short antennal scape, in the widely oval elytra convex laterally and bearing small tubercles only in the apical part of the 5th and 7th interstriae, in a straight and long fore tibia, and also in the presence of 2 small sclerites in the area of the aggonoporium of the endophallus.

Etymology. The name of the new species is the Latin masculine adjective “vulgaris” (common).

Stiltoblosyrus gracilis Davidian, sp. n. (Fig. 2, 1; Fig. 5, 6)

Material. Holotype: ♂, China, Yunnan Prov., N of Lanping, 11.3 km SW of Hexi, 26°48ʹ34ʺN, 99°17ʹ16ʺE, H = 3600 m, 10.VI.2016 (G.E. Davidian, I.I. Kabak). Paratype: 1 ♀, as holotype.

Description. Male. Rostrum 1.17 times as wide as long. Head at level of eyes 1.48 times as wide as frons, 1.55 times as wide as rostrum at apex. Rostral dorsum compressed laterally in middle part, parallel-sided in apical half. Length of antennal scape slightly exceeding width of rostrum at antennal insertion; 1st funicular antennal segment 2.32 times as long as wide, slightly wider than 2nd segment; 2nd segment 3.29 times as long as wide, 1.3 times as long as 1st and 2.17 times as long as 3rd one; 3rd–6th segments subequal in length, about 1.5 times as long as wide; 7th slightly wider, 1.4 times as long as wide. Club of antenna fusiform, widest slightly distal to midlength, 2.2 times as long as wide, with sides almost rectilinearly converging toward base in basal half.

Fig. 2.
figure 2

Stiltoblosyrus gen. n., male [(1–3) holotype, (4) paratype]: (1) S. gracilis sp. n., (2) S. delavayi sp. n., (3) S. laticollis sp. n., (4) S. brevicornis sp. n.

Full size image

Pronotum widest distal to midlength, 1.4 times as wide as long, compressed laterally in basal half, slightly raised along midline on disc, with numerous small granules and with several large tubercles.

Elytra oblong-oval, 1.4 times as long as wide, slightly convex laterally in middle part. Elytral striae formed by rather large punctures subequal in width to 2 first interstriae; 6th interstria widest, twice as wide as striae. Sutural and even-numbered interstriae and also elytral striae with small uniform granules. Elytra before apical declivity with transverse row of large tubercles on 3rd, 5th, and 7th interstriae and with 1 large tubercle at apex of 5th interstria distal to this transverse row.

Legs slender; tibiae slender and long. Fore tibia straight, incurved in preapical part, 2.14 times as long as antennal scape, with inclined spiniform granules at inner margin. Hind tibia narrow, nearly straight, with rounded outer apical angle, with small granules along inner margin; process at apex of hind tibia triangular, 1.37 times as long as wide, 0.62 times as long as 1st, and slightly longer than 2nd segment of hind tarsus. 2nd segment of fore tarsus slightly elongate, slightly shorter than 3rd segment; 1st segment of hind tarsus 3.1 times as long as wide and twice as long as 2nd segment; 2nd segment 1.4 times as long as wide.

Venter slightly elongate, 2.4 times as wide as intercoxal process of ventrite I; ventrite I flat, slightly depressed medially in apical half; ventrite V 1.47 times as wide as long, with shallow median depression.

Penis subparallel-sided in middle part, slightly longer than apophyses of aedeagus. Lamella of penis in the form of equilateral triangle slightly compressed laterally and very narrowly rounded apically; ostial plate considerably narrower than penis, with shallow obtuse-angular emargination basally.

Vestiture pale brown and yellowish, with golden metallic sheen, formed by recumbent lanceolate scales pointed apically, by shorter setae in elytral striae, and by longer setiform hairs situated on interstriae and clearly visible at apices of tubercles. Inner margin of hind tibia with obliquely erect fine hairs as long as, or longer than width of tibia; process at apex of tibia with dense subrecumbent hairs dorsally and on outer side.

Body length of holotype 6.75 mm, width 3.40 mm.

Female. Elytra weakly elongate, 1.16 times as long as wide. Legs robust; fore tibia straight, slightly incurved in apical part, with row of slanting spines along inner margin distal to middle. Fore tibia twice as long as antennal scape. Hind tibia straight, with very small spiniform granules on inner margin. 1st segment of hind tarsus 1.9 times as long as wide; 2nd one 1.44 times as long as wide. Ventrites I and V slightly convex, without depression.

Body length 7.0 mm, width 4.0 mm.

Comparative diagnosis. Stiltoblosyrus gracilis differs from most of the congeners in a widely triangular process at the apex of the hind tibia of the male. It is very closely related to S. delavayi sp. n. but differs as follows: the head at the level of the eyes is 1.55 times as wide as the apex of the rostrum; the rostral dorsum is rather strongly compressed laterally in the middle, subparallel-sided in the distal half; the sides of the pronotum are slightly concave in the basal half; the process at the apex of the hind tibia bears no accessory tooth on the ventral side before the apex.

Biology. The insects were collected at night by beating rhododendron branches.

Etymology. The name of the new species is the Latin masculine adjective “gracilis” (gracious).

Stiltoblosyrus delavayi Davidian, sp. n. (Fig. 2, 2; Fig. 5, 6)

Material. Holotype: ♂, China, Yunnan Prov., Laojunshan Mts., 6.26 km SSW of Segengsheng, 27°0ʹ20ʺN, 99°28ʹ33ʺE, H = 3575 m, 6.VI.2016 (G.E. Davidian).

The holotype lacks the left middle tibia with the tarsus.

Description. Male. Rostrum distinctly narrowed toward apex, 1.26 times as wide as long. Rostral dorsum weakly compressed laterally, gradually narrowed toward apex in distal half. Eyes round, strongly convex; head at level of eyes 1.43 times as wide as frons and 1.69 times as wide as rostrum at apex. Length of antennal scape 1.11 times width of rostrum at antennal insertion; 1st funicular antennal segment 0.83 times as long as 2nd segment; 2nd segment 2.86 times as long as wide, 2.4 times as long as 3rd; 3rd, 4th, and 6th segments subequal in length, 1.25 times as long as wide; 5th segment slightly shorter; 7th wider and slightly longer than others. Club of antenna fusiform, widest slightly distal to midlength, 2.1 times as long as wide, with lateral margins straight in basal half.

Pronotum transverse, not compressed laterally, 1.45 times as wide as long, with large tubercles in basal half on disc.

Elytra oval, 1.27 times as long as wide, with large, strongly convex tubercles on disc and apical declivity.

Fore tibia straight, considerably incurved in preapical part, 2.04 times as long as antennal scape. Hind tibia with strongly slanting outer apical angle; process at apex triangular, 1.37 times as long as wide, with small accessory tooth ventrally near apex, 0.6 times as long as 1st, and slightly shorter than 2nd segment of hind tarsus. 1st segment of hind tarsus 2.5 times as long as wide and 1.67 times as long as 2nd segment; 2nd segment 1.5 times as long as wide.

Venter slightly longer than wide, 2.57 times as wide as intercoxal process of ventrite I; ventrite V 1.5 times as wide as long.

Apophyses of aedeagus 1.9 times as long as penis. Penis 1.53 times as long as wide, parallel-sided in basal half, lamella of penis transversely triangular, narrowly rounded apically; ostial plate considerably narrower than penis, with straight basal margin.

Vestiture of body slightly worn, yellowish gray with weak metallic sheen, almost uniform dorsally and laterally; tubercles on elytra mainly without erect hairs. Inner margin of hind tibia with rather sparse, erect hairs slightly shorter than width of tibia.

Body length of holotype 6.5 mm, width 3.3 mm.

Female unknown.

Comparative diagnosis. Stiltoblosyrus delavayi differs from most of the congeners in a widely triangular process at the apex of the hind tibia of the male. It is very closely related to S. gracilis sp. n. in the proportions of the body and in the structure of the process at the apex of the male hind tibia, but differs as follows: the head at the level of the eyes is 1.69 times as wide as the rostrum at the apex, the rostral dorsum is weakly compressed laterally and gradually narrowed in the apical half, the tubercles on the pronotum and elytra are larger, the pronotum is not compressed laterally in the basal half, the hind tibia has a strongly slanting outer apical angle, the process at the apex of the tibia bears a small accessory tooth ventrally before the apex, and the aedeagus is more widely rounded apically.

Etymology. The new species is named after the French missionary Père Jean Marie Delavay (1834–1895), one of the first researchers of the nature of Chinese province of Yunnan; noun in genitive, invariable.

Stiltoblosyrus laticollis Davidian, sp. n. (Fig. 2, 3; Fig. 5, 2)

Material. Holotype: ♂, China, Yunnan Prov., W of Dali City, SW of Yangbi, northeastern slope of Mt. Laoheshang, 25°35ʹ57ʺN, 99°55ʹ03ʺE, H = 3120 m, 22.V.2019 (I.A. Belousov, I.I. Kabak, G.E. Davidian). Paratypes: same locality, 1.3 km S of Mt. Laoheshang, 25°34ʹ58ʺN, 99°54ʹ15ʺE, H = 3070 m, 23.V.2019 (I.A. Belousov, I.I. Kabak, G.E. Davidian), 2 ♀.

Description. Male. Rostrum distinctly narrowed toward apex, 1.26 times as wide as long. Rostral dorsum compressed laterally in middle part, subparallel-sided in apical half. Eyes hemispherically convex; head at level of eyes 1.43 times as wide as frons. Length of antennal scape 1.14 times width of rostrum at antennal insertion; 1st funicular antennal segment 2.67 times as long as wide; 2nd segment considerably narrower than, and 1.17 times as long as 1st segment; 3rd–5th segments similar, slightly elongate; 6th segment slightly larger; 7th widest, slightly elongate. Club of antenna fusiform, widest at midlength, 2.45 times as long as wide, slightly compressed laterally in basal half.

Pronotum strongly transverse, 1.57 times as wide as long, widely rounded laterally, widest distal to midlength, with transverse constriction before basal margin; disc slightly swollen, with small shining granules and with matte-shining large tubercles mainly in basal half.

Elytra 1.12 times as long as wide, weakly convex laterally in middle part. Elytral interstriae 1.5–2 times as wide as striae. Sutural and even-numbered elytral interstriae with sparse small granules most convex on apical declivity. Elytra before base with largest tubercle on 7th interstria, in apical part with transverse row of large tubercles before apical declivity and with large conical tubercle at apex of 5th interstria.

Fore tibia straight, distinctly incurved in preapical part, slightly concave along outer margin, with 2 or 3 large dentiform spines at inner margin. Hind tibia slightly curved dorsoventrally, with several strongly slanting spines on inner margin. Fore and middle tibiae with simple dentiform mucro; process at apex of hind tibia slightly larger, weakly downcurved apically, with accessory tooth ventrally near apex, shorter than 2nd segment of hind tarsus. 2nd segment of fore tarsus slightly elongate, shorter than 3rd; 1st segment of hind tarsus 2.09 times as long as wide; 2nd segment 1.62 times as long as wide, equal in length to 3rd segment, 0.72 times as long as 1st.

Venter slightly transverse, 2.02 times as wide as intercoxal process of ventrite I; ventrites I and V with superficial median depression; ventrite V narrowly rounded apically.

Apophyses of aedeagus 1.52 times as long as penis. Penis subparallel-sided in middle part; lamella slightly compressed laterally, with apex widely obtused and shallowly emarginate in middle; ostial plate elongately horseshoe-shaped, not projecting beyond contour of penis.

Vestiture copper-colored with golden sheen. Pronotum with recumbent lanceolate scales and longer raised setiform hairs. Scales on elytra slightly shorter and wider, similar to, or slightly narrower than setae in elytral striae; setiform hairs on interstriae obliquely erect, noticeably longer, most distinct on tubercles. Widest scales about 2.3 times as long as wide. Lateral surface of pronotum with sparse vestiture; entire 10th elytral interstria with sparse scales.

Body length of holotype 6.8 mm, width 3.8 mm.

Female. Club of antenna 2.25 times as long as wide. Middle part of frons and vertex convex. Pronotum 1.49 times as wide as long. Elytra nearly rounded, 1.05 times as long as wide. Largest tubercle on elytra situated at apex of 5th interstria. Fore tibia curved nearly as that in male. 2nd segment of fore tarsus as long as wide; 2nd segment of hind tarsus 1.19 times as long as wide. Ventrite I convex; ventrite V nearly flat. Ramus and collum of spermatheca subequal in length.

Body length 6.6–6.7 mm, width 4.0 mm.

Comparative diagnosis. Stiltoblosyrus laticollis differs from most of the congeners in wide-lanceolate scales on the elytra and also in a very small (shorter than the 2nd segment of the hind tarsus) process at the apex of the male hind tibia. The new species is most closely related to S. brevicornis sp. n. but differs as follows: the rostrum is distinctly narrowed toward the apex, the 2nd funicular antennal segment is noticeably longer than the 1st one, the pronotum is more transverse (1.5 times as wide as long), the fore tibia is slightly concave along the outer margin in the preapical part, its outer apical angle is not widened, the process at the apex of the male hind tibia bears an accessory tooth ventrally before the apex, ventrite V is narrowly rounded apically, the lamella of the penis is clearly narrowed toward the apex and widely obtused.

Biology. The male was collected by sifting the forest litter, and both the females, by beating rhododendron branches at night.

Etymology. The name of the new species is a Latin masculine adjective formed by “latus” (wide) and “collum” (a neck).

Stiltoblosyrus brevicornis Davidian, sp. n. (Fig. 2, 4; Fig. 5, 3; Fig. 6, 3)

Material. Holotype: ♂, China, Yunnan Prov., Diancan Shan, 0.8 km ENE of Mt. Wutaifeng, 25°49ʹ27ʺN, 100°01ʹ40ʺE, H = 3665 m, 27.V.2019 (I.A. Belousov, I.I. Kabak, G.E. Davidian). Paratypes: 11 ♂, 5 ♀, as holotype; 0.9 km NW of Mt. Lianhuafeng, 25°47ʹ39ʺN, 100°01ʹ40ʺE, H = 3675 m, 28.V.2019 (I.A. Belousov, I.I. Kabak, G.E. Davidian), 1 ♂.

Description. Male. Rostrum 1.19 times as wide as long, parallel-sided in apical half or slightly narrowed toward apex. Rostral dorsum compressed laterally, narrowest at midlength. Eyes hemispherical, most convex slightly behind the middle; head at level of eyes 1.48 times as wide as frons. Antennal scape weakly convex outward before base, its length slightly exceeding width of rostrum at antennal insertion; 2nd funicular segment 2.25 times as long as wide, slightly narrower than, or as long as 1st segment, slightly longer or shorter than it; 3rd and 4th segments similar, slightly elongate, 0.55 times as long as 2nd one; 5th segment nearly round; 6th wider and slightly elongate; 7th widest, as long as wide, slightly narrower than antennal scape in apical part and 1.75 times as wide as 2nd funicular segment. Club of antenna fusiform, widest at midlength, 2.3 times as long as wide.

Pronotum 1.45–1.49 times as wide as long, widest distal to midlength, slightly compressed laterally before base; disc with small shining granules subequal in size to punctures in elytral striae, also with large tubercles mainly in basal half.

Elytra oval, 1.17 times as long as wide, weakly convex laterally in middle part. Interstriae 1.5–3 times as wide as striae. Sutural and even-numbered interstriae with small granules similar to those on pronotum. Elytra before apical declivity with transverse row of large tubercles on 3rd, 5th, and 7th interstriae and also with large tubercle at apex of 5th interstria.

Fore tibia straight, clearly incurved and weakly concave on outer side in preapical part; outer apical angle slightly widened; inner margin with row of rather long spines in apical half. Process at apex of hind tibia small, 0.71 times as long as 2nd segment of hind tarsus. 2nd segment of fore tarsus as long as wide; 1st segment of hind tarsus 2.11 times as long as wide; 2nd segment slightly elongate, 0.53 times as long as 1st one.

Venter slightly transverse, 2.07 times as wide as intercoxal process of ventrite I; ventrite I clearly depressed; apical margin of ventrite V widely rounded, with wide superficial median depression.

Apophyses of aedeagus 2.57 times as long penis. Penis very short and wide; penis tube transverse, 1.24 times as wide as long; apex of lamella of penis widely rounded, with small median emargination; ostial plate not projecting beyond contour of penis.

Vestiture copper-colored with matte sheen. Pronotum with lanceolate recumbent scales. Scales on elytra mainly shorter and wider, occasionally oblong-oval, clearly narrower than setae in elytral striae, 0.50–0.67 times as long as subrecumbent setiform hairs on interstriae. Elytra with densest vestiture in preapical part, with ill-defined transverse band before apical declivity. Sides of mesothorax with sparse vestiture; 10th elytral interstria nearly glabrous in basal half.

Body length 6.2–7.3 mm, width 3.4–4.2 mm; those in holotype 6.63 mm and 3.5 mm, respectively.

Female. Frons clearly convex in middle part, with fine median sulcus. Pronotum 1.44–1.57 times as wide as long. Elytra 1.13 times as long as wide. Fore tibia slightly incurved in preapical part; outer apical angle weakly widened. Ventrite I convex; ventrite V triangular, narrowly rounded apically.

Body length 6.55–7.3 mm, width 3.9–4.2 mm.

Comparative diagnosis. Stiltoblosyrus brevicornis differs from most of the congeners mainly in wide-lanceolate and oblong-oval scales on the elytra and also in a small (shorter than the 2nd segment of the hind tarsus) process at the apex of the hind tibia of the male. The new species is most closely related to S. laticollis sp. n. but differs as follows: the rostrum is parallel-sided in the apical half or slightly narrowed toward the apex, the 2nd funicular antennal segment is 2.25 times as long wide and subequal in length to the 1st one, the pronotum is less transverse, the fore tibia of the male is weakly concave along the outer margin in the preapical part, the outer apical angle is slightly widened, ventrite V is superficially depressed and apically widely rounded, the lamella of the penis is widely rounded at the apex.

Biology. The insects were collected at night in the upper belt of the growth of bamboo on the soil surface near rhododendron bushes (Fig. 6, 3).

Etymology. The name of the new species is a Latin masculine adjective formed by “brevis” (short) and “cornu” (a horn).

Stiltoblosyrus kabaki Davidian, sp. n. (Fig. 3, 1; Fig. 5, 10)

Material. Holotype: ♂, China, Yunnan Prov., Mts Laojunshan, NE of Liming, 4.2 km S of Muzhengdu, 27°6ʹ34ʺN, 99°45ʹ3ʺE, H = 3695 m, 3.VI.2016 (G.E. Davidian). Paratypes: 3 ♀, as holotype.

Description. Male. Rostrum weakly transverse, gradually narrowed toward apex, 1.19 times as wide as long. Rostral dorsum rather strongly compressed laterally, narrowest at midlength, distinctly rounded laterally in apical half. Eyes strongly convex, nearly hemispherical; head at level of eyes 1.46 times as wide as frons. Length of antennal scape 1.13 times width of rostrum at antennal insertion; 1st funicular antennal segment slightly wider than and 0.81 times as long as 2nd one; 2nd segment 3.2 times as long as wide and 2.28 times as long as 3rd; 3rd segment equal to 6th one, 1.4 times as long as wide; 4th and 5th segments elongate, slightly shorter than 3rd; 7th widest, 1.23 times as long as wide. Club of antenna fusiform, widest distal to midlength, 2.33 times as long as wide, slightly compressed laterally in basal half, twice as long as 1st segment.

Fig. 3.
figure 3

Stiltoblosyrus gen. n., male [(1) holotype, (2–4) paratype]: (1) S. kabaki sp. n., (2) S. lisu sp. n., (3) S. andreii sp. n., (4) S. curvimanus sp. n.

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Pronotum widest distal to midlength, 1.43 times as wide as long, clearly constricted laterally before base, with numerous granules and several large tubercles on disc.

Elytra widely oval, 1.29 times as long as wide, weakly convex laterally in middle part; interstriae 2–3 times as wide as striae. Sutural and even-numbered interstriae with small granules; 3rd, 5th, and 7th interstriae with rows of large tubercles. Large tubercle at base of 5th interstria not projecting beyond contour of humeri; distance between 2 large tubercles at apex of 5th interstria distinctly shorter than that between last of them and small tubercle at place of merging of 3rd and 9th interstriae.

Fore tibia S-curved, clearly incurved in apical part, with several spiniform granules along inner margin. Hind tibia ventrally considerably convex in basal half, with distinct round granules; process of inner apical angle 1.32 times as long as wide, narrowly rounded apically, deeply longitudinally sulciform concave laterally, 1.5 times as wide and 0.58 times as long as 1st segment, 1.25 times as long as 2nd segment. 2nd segment of fore tarsus 1.5 times as long as wide, slightly shorter than 3rd segment; 1st segment of hind tarsus 3.35 times as long as wide; 2nd segment 1.91 times as long as wide, slightly longer than 3rd segment.

Aedeagus short and wide; penis and apophyses equal in length; penis arcuately curved dorso-ventrally, 1.43 times as long as wide, subparallel-sided at midlength, widely rounded and shallowly emarginate medially at apex; ostial plate horseshoe-shaped.

Vestiture mainly brown with golden sheen, with paler and denser scales in preapical part of elytra and in transverse band before apical declivity. Recumbent lanceolate, apically pointed scales on elytra 1.5–2 times as long as setae in elytral striae, 0.50–0.67 times as long as setiform hairs; latter most distinct on tubercles. Lateral surface of pronotum and elytra with distinct vestiture. Process at apex of hind tibia with dense long hairs dorsally.

Body length of holotype 8.1 mm, width 4.1 mm.

Female. Frons flat or slightly convex in middle part. Eyes strongly convex; head at level of eyes 1.54–1.6 times as wide as frons. Pronotum 1.53 times as wide as long. Elytra widely oval, 1.2 times as long as wide. Fore tibia in apical half about uniform in width; 2nd segment of fore tarsus slightly elongate; 1st segment of hind tarsus 1.67 times as long as 2nd one; 2nd segment 1.49 times as long as wide. Ventrite I flat.

Body length 7.6–8.1 mm, width 4.2–4.6 mm.

Comparative diagnosis. Stiltoblosyrus kabaki clearly differs from all the species in the following characters: the process at the apex of the hind tibia is longitudinally sulciform concave laterally, narrowly rounded distally, 1.5 times as wide and 0.58 times as long as the 1st segment of the hind tarsus. The new species differs from S. gracilis sp. n. and S. delavayi sp. n., also possessing a wide process at the apex of the male hind tibia, in a larger body, in an S-curved fore tibia of the male, and in a widely rounded apex of the aedeagus.

Biology. The insects were collected at night, probably from iris.

Distribution. The species occurs together with S. titanicus sp. n. and S. pulcher sp. n.

Etymology. The new species is named after I.I. Kabak; noun in genitive, invariable.

Stiltoblosyrus lisu Davidian, sp. n. (Fig. 3, 2; Fig. 5, 11)

Material. Holotype: ♂, China, W Yunnan Prov., SSW of Liuku, from 25°41ʹ19ʺN, 98°46ʹ07ʺE to 25°41ʹ13ʺN, 98°46ʹ03ʺE, H = 3735–3815 m, 20.V.2006 (I.A. Belousov, I.I. Kabak). Paratypes: 6 ♂, 7 ♀, as holotype; same locality, SW of Liuku, 25°42ʹ58ʺN, 98°45ʹ11ʺE, H = 3640 m, 24.V.2006 (I.A. Belousov, I.I. Kabak), 1 ♀.

Description. Male. Integument glossy. Rostrum slightly transverse, 1.17 times as wide as long. Rostral dorsum compressed laterally in middle part, subparallel-sided in apical half, separated from frons by transverse sulcus deepest in middle part. Head and pronotal disc dorsally mostly with micropunctation. Eyes strongly convex; posterior margin of eyes strongly raised above lateral surface of head; head at level of eyes 1.47 times as wide as frons. Length of antennal scape 1.17 times width of rostrum at antennal insertion; 1st funicular antennal segment slightly shorter than 2nd segment; 2nd segment 3.4 times as long as wide, 2.25 times as long as 3rd; 3rd–7th segments weakly elongate; 7th segment widest; club fusiform, widest at midlength, 2.29 times as long as wide, with lateral margins rectilinearly converging toward base in basal half.

Pronotum widely rounded laterally, widest near, or slightly distal to midlength, 1.3 times as wide as long, weakly constricted before basal margin, with smoothened tubercles on disc.

Elytra 1.34 times as long as wide, subparallel-sided in medial 2/3. Striae partly confused and vague; interstriae 1.5–2 times as wide as striae. Sutural and even-numbered interstriae with smoothened granules larger than punctures in striae. Elytra with large, occasionally merging tubercles on 3rd, 5th, and 7th interstriae; largest tubercles forming transverse row before apical declivity on 3rd and 5th interstriae; 1 large tubercle preset at apex of 5th interstria.

Legs slender, long. Fore tibia smoothly incurved in apical half. Hind tibia truncate apically, with straight outer apical angle, ventrally deeply emarginate before corbel, with angular projection before emarginations. Process of inner apical angle knife-shaped, pointed apically, with straight dorsal margin, with ventral margin convex in apical half and occasionally with angular ledge before base, 1.2 times as long as 1st segment of hind tarsus. 2nd segment of fore tarsus elongate; 1st segment of hind tarsus 2.64 times as long as wide, 1.75 times as long as 2nd segment.

Venter slightly longer than wide, 2.4 times as wide as intercoxal process of ventrite I; ventrite I weakly depressed, slightly shorter than ventrites II–IV combined; ventrite V moderately convex, with superficial depression in middle part.

Apophyses of aedeagus 1.85 times as long penis; penis 1.4 times as long as wide. Lamella of penis transverse, with widely rounded apex slightly obtused in middle. Endophallus entirely densely covered with small sclerites, with 2 large symmetrical sclerites at level of basal 1/3 of apophyses, with serrate inner margin.

Vestiture pale gray, occasionally with brownish tint, without metallic sheen, densest on apical elytral declivity; sides of elytra nearly glabrous. Baculiform recumbent scales obtused, rarely slightly pointed apically, 4–6 times as long as wide; raised setiform hairs 1.5– 2 times as long as scales, most distinct on tubercles and apical elytral declivity. Angular projection on ventral side of hind tibia with long erect setae before emargination.

Body length 8.6–9.7 mm, width 4.0–4.5 mm; those in holotype 9.0 and 4.15 mm, respectively.

Female. Fore tibia straight or slightly incurved in apical part. Hind tibia truncate apically. Venter 2.65 times as wide as intercoxal process of ventrite I; ventrite I convex in middle part; ventrites II–IV weakly punctate, nearly glossy black; ventrite V triangular. Vagina bearing long sclerotized stripe with accessory areas of sclerotization (occasionally ill-defined) at sides.

Body length 8.9–10.3 mm, width 4.8–5.6 mm.

Comparative diagnosis. Stiltoblosyrus lisu differs from all the congeners in the following characters: the pronotum is widest at the midlength; the hind tibia of the male is truncate apically and deeply emarginate along the inner margin before the corbel; the sides of the elytra are nearly glabrous; the aedeagus is large, with 2 large sclerites in the basal part of the endophallus; the vagina is usually more heavily sclerotized.

Etymology. The new species is named after one of the nationalities inhabiting Yunnan Province of China; noun in apposition, invariable.

Stiltoblosyrus andreii Davidian, sp. n. (Fig. 3, 3; Fig. 5, 13; Fig. 6, 1, 2)

Material. Holotype: ♂, China, Yunnan Prov., N of Weixi City, 2.7 km S of Apu Vill., 27°17ʹ17ʺN, 99°19ʹ37ʺE, H = 3250 m, 22.VI.2019 (G.E. Davidian). Paratypes: 8 ♂, 2 ♀, as holotype; same locality, SW of Guoditang, 6.4 km ENE of Weixi City, 27°12ʹ38ʺN, 99°21ʹ22ʺE, H = 3235 m, 29.V.2016 (G.E. Davidian, I.I. Kabak, A.A. Molchanov), 1 ♂.

Description. Male. Rostrum gradually narrowed toward apex. Frons moderately convex in middle part, separated from eyes by depressions. Eyes round, almost hemispherically convex, with posterior margins rather strongly raised above lateral surface of head; head at level of eyes 1.44 times as wide as frons. Length of antennal scape 1.12 times width of rostrum at antennal insertion; 1st funicular antennal segment 0.77 times as long as 2nd one; 2nd segment 3.44 times as long as wide; 3rd–7th segments slightly elongate; 5–7th occasionally almost round; 7th segment widest; club fusiform, widest at midlength, 2.17 times as long as wide; lateral margins straight in basal half.

Pronotum widest distal to midlength, 1.4 times as wide as long, weakly constricted laterally before base; disc with small rounded shining granules and rather small tubercles shining apically; median carina ill-defined or absent.

Elytra oviform, 1.3 times as long as wide; interstriae 2–3 times as wide as striae. Sutural and even-numbered interstriae with row of small granules equal in size to punctures in striae; 3rd, 5th, and 7th interstriae with tubercles among which largest one forming transverse row before apical declivity. Distance between 2 large tubercles in apical part of 5th interstria distinctly longer than that between the last of them and small tubercle at place of merging of 3rd and 9th interstriae.

Fore tibia weakly S-curved, considerably incurved in apical part. Hind tibia curved dorsoventrally and strongly flattened laterally; ventral margin of tibia angularly widened before base; dorsal side with fine sulcate sculpture in basal half. Fore and middle tibiae with numerous, partly spiniform tubercles on inner margin; hind tibia almost entirely smooth. Articular surface of hind tibia with long sword-shaped process behind place of attachment of tarsus; this process directed backwards, equal to length of 2 first tarsal segments combined, with lower margin usually bearing distinct setiferous tooth at base. 2nd segment of fore tarsus nearly as long as wide; 1st segment of hind tarsus very long, 3.1 times as long as wide; 2nd segment elongate, 0.41 times as long as 1st one.

Venter 2.67 times as wide as intercoxal process of ventrite I; ventrite V convex, with round median depression in apical half.

Aedeagus rather short; penis and apophyses subequal in length; penis convex laterally, widest in middle part, 1.9 times as long as wide. Lamella of penis strongly narrowed toward apex, narrowly rounded at end, half as long as penis; ostial plate as long as wide, widely rounded along apical margin, usually not projecting beyond contour of lamella.

Vestiture formed by recumbent lanceolate scales pointed at end, mainly brown and pale brown, occasionally interspersed with pale gray and white scales. Length of scales on interstriae and setae in striae subequal to diameter of punctures in striae; obliquely erect setiform hairs on odd-numbered interstriae longer. Lateral surface of elytra with distinct vestiture. Inner margin of hind tibia with short row of hairs before apical angle.

Body length 7.3–8.4 mm, width 3.7–4.2 mm; those in holotype 7.7 and 3.7 mm, respectively.

Female. Frons strongly convex in medial 1/3, with median sulcus. Pronotum with obliterate callus-shaped median carina. Elytra widely oviform. Venter 2.9 times as wide as intercoxal process of ventrite I. Fore tibia straight, widened toward apex, slightly incurved along outer margin in apical part. Ventral margin of hind tibia nearly straight, cariniformly bordered in preapical part. 1st segment of hind tarsus 1.9 times as long as wide; 2nd segment elongate, 0.56 times as long as 1st one.

Body length 7.90–8.30 mm, width 4.55–4.95 mm.

Comparative diagnosis. Stiltoblosyrus andreii clearly differs from all the congeners in the following characters: the distance between 2 large tubercles in the apical part of the 5th interstria is distinctly longer than that between the last of them and a small tubercle at the place of merging of the 3rd and 9th interstriae; the hind tibia of the male is strongly flattened laterally, curved dorsoventrally, with a fine sulcate sculpture dorsally in the basal half; the ventral margin of the tibia is angularly widened before the base; behind the place of attachment of the tarsus, the articular surface bears a long sword-shaped process directed backwards; the 1st segment of the hind tarsus is 3.1 times as long as wide. In addition, the new species differs from the majority of the species in the frons strongly convex in the middle part, in an S-curved fore tibia of the male, and in the structure of the aedeagus.

Biology. The insects were collected at night by beating rhododendron branches of (Fig. 6, 1, 2).

Etymology. The new species is named after my comrade Andrei Andreevich Molchanov, a participant of our numerous expeditions to the Caucasus, Siberia, Turkey, and China. Noun in genitive, invariable.

Stiltoblosyrus curvimanus Davidian, sp. n. (Fig. 3, 4; Fig. 5, 12; Fig. 6, 4)

Material. Holotype: ♂, China, Yunnan Prov., N of Weixi City, mountain 4.2 km E of Lidima Vill., 27°40ʹ34ʺN, 99°19ʹ14ʺE, H = 4100 m, 23.VI.2015 (G.E. Davidian). Paratypes: 1 ♂, 2 ♀, as holotype; same locality, N of Weixi City, Dewei Line, mountain range between Xiaruolisuzuxiang and Yezhizhen villages, 27°39ʹ05ʺN, 99°10ʹ26ʺE, H = 3785 m, 13.VI.2013 (I.A. Belousov, I.I. Kabak, G.E. Davidian), 1 ♂, 1 ♀; same locality, 27°39ʹ18ʺN, 99°10ʹ27ʺE, H = 3935 m, 13.VI.2013 (I.A. Belousov, I.I. Kabak, G.E. Davidian), 1 ♂.

Description. Male. Rostrum considerably narrowed toward apex, 1.26 times as wide as long. Rostral dorsum compressed laterally in middle, subparallel-sided in apical half. Eyes hemispherical, most convex slightly behind middle; head at level of eyes 1.52 times as wide as frons. Frons weakly convex, with deep depression in middle and minute median sulcus not reaching vertex. Length of antennal scape slightly exceeding width of rostrum at antennal insertion; 1st funicular antennal segment 2.5 times as long as wide; 2nd segment 3.13 times as long as wide, narrower than, and 1.04 times as long as 1st one; 3rd segment 1.33 times as long as wide, 0.46 times as long as 2nd segment; 4th and 5th segments slightly elongate; 6th round; 7th slightly wider than preceding segment, round, widest, 1.41 times as wide as 1st segment. Club widely fusiform, widest at midlength, 2.09 times as long as wide, slightly convex laterally in basal half.

Pronotum widest distal to midlength, 1.36 times as wide as long, with transverse constriction before base; disc with small shining granules most distinct at sides and with numerous large tubercles.

Elytra oblong-oval, parallel-sided in middle part, 1.32 times as long as wide. Elytral striae formed by rather large punctures, distinctly narrower than interstriae; sutural and even-numbered interstriae with sparse small granules equal in size to, or smaller than those on pronotal disc. Largest tubercles at base of elytra situated on 5th and 7th interstriae, first of them slightly projecting beyond contour of slanting humeri. Largest tubercles on elytral apex situated on 3rd interstria before apical declivity and at apex of 5th interstria.

Fore tibia angularly incurved in apical 1/3, with distinct slanting spines along inner margin. Hind tibia almost regularly arcuately curved; its inner margin smooth in apical half, without granules; process of inner apical angle with weak transverse constriction in middle part, rounded apically, 0.76 times as wide and 0.48 times as long as 1st tarsal segment, 0.85 times as long as 2nd segments. 2nd segment of fore tarsus slightly elongate; 1st segment of hind tarsus 2.5 times as long as wide; 2nd segment 1.45 times as long as wide, subequal in length to 3rd one.

Venter slightly longer than wide, 2.58 times as wide as intercoxal process of ventrite I; ventrite I shallowly depressed; ventrite V 1.74 times as wide as long, widely rounded apically, with round, rather deep depression in apical half.

Apophyses of aedeagus 1.26 times as long as penis. Penis parallel-sided in basal part, slightly compressed laterally before lamella, 1.79 times as long as wide; lamella triangular, narrowly rounded apically; ostial plate as long as wide, acute-angularly emarginate basally.

Vestiture of dorsal side mainly brownish with matte metallic sheen; elytra with wide transverse yellow band before apical declivity. Pronotum with recumbent, nearly hair-like scales, slightly interspersed with wider lanceolate scales. Scales on elytra shorter, widest of them forming transverse band; subrecumbent setiform hairs slightly longer, clearly visible on tubercles and on apical declivity. Lateral surface of pronotum and elytra with distinct vestiture; wide parts of femora with transverse pale bands; hind tibia of male with dense row of erect hairs along inner margin in apical 1/4.

Body length 6.95–7.5 mm, width 3.5–3.8 mm; those in holotype 7.5 and 3.7 mm, respectively.

Female. Club short, 1.8 times as long as wide. Fore tibia considerably incurved before apex; hind tibia slightly curved dorso-ventrally and inward. Pronotum 1.34 times as wide as long; elytra 1.17 times as long as wide. Venter as long as wide; ventrite V flat, 1.52 times as wide as long. Collum of spermatheca slightly wider than, and about twice as long as ramus.

Body length 7.4 mm, width 4.1–4.15 mm.

Comparative diagnosis. Stiltoblosyrus curvimanus differs from all the congeners in the following characters of the male: the hind tibia is strongly arcuately curved dorsoventrally and smooth on the inner margin in the apical half; the process of the inner apical angle is weakly transversely constricted in the middle part, rounded at the end, 0.85 times as long as the 2nd segment of the hind tarsus; ventrite V is deeply roundly depressed in the apical half.

Biology. The insects were collected at night by beating branches of treelike rhododendron with white flowers.

Etymology. The name of the new species is a Latin masculine adjective formed by the verb “curvare” (to curv) and “manus” (a hand).

Stiltoblosyrus longipes Davidian, sp. n. (Fig. 4, 1; Fig. 5, 14)

Material. Holotype: ♂, China, Yunnan Prov., Laojunshan, watershed of the rivers running to Shigu and Liming, 26°53ʹ27ʺN, 99°39ʹ14ʺE, H = 3950 m, 4.VI.2014 (I.A. Belousov, I.I. Kabak). Paratypes: same locality, eastern slope of Mt. Laojunshan, 26°52ʹ17ʺN, 99°37ʹ53ʺE, H = 3780 m, 4.VI.2014 (I.A. Belousov, I.I. Kabak), 2 ♂, 1 ♀; same locality, Laojunshan, watershed of the rivers running to Shigu and Liming, H = 3795 m, 3.VI.2014 (I.A. Belousov, I.I. Kabak), 1 ♂, 2 ♀.

Description. Male. Rostrum 1.21 times as wide as long, weakly narrowed from base, subparallel-sided in preapical part. Rostral dorsum distinctly compressed laterally, narrowest near middle, slightly widened toward apex. Head at level of eyes 1.36 times as wide as frons. Length of antennal scape slightly exceeding width of rostrum at antennal insertion; 1st funicular segment slightly wider than 2nd segment; 2nd segment 4 times as long as wide and 1.33 times as long as 1st segment; 3rd–6th segments subequal, weakly elongate, 0.37 times as long as 2nd segment; 7th segment widest, slightly elongate or as long as wide; club fusiform, widest at midlength, twice as long as wide.

Fig. 4.
figure 4

Stiltoblosyrus gen. n., male [(1, 2, 4) paratype; (3) holotype]: (1) S. longipes sp. n., (2) S. zhangi sp. n., (3) S. titanicus sp. n., (4) S. asyae sp. n.

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Pronotum widest distal to midlength, 1.32 times as wide as long; disc with tubercles and granules most numerous at sides.

Elytra oblong-oval, with flattened disc, subparallel-sided in middle part, 1.26 times as long as wide; tubercle at base of 5th interstria not projecting beyond contour of the slanting humeri. Interstriae 1.5–2 times as wide as striae. Sutural and even-numbered interstriae with vague row of small granules. Distance between 2 large tubercles in apical part of 5th interstria distinctly shorter than that between last of them and small tubercle at place of merging of 3rd and 9th interstriae.

Fore tibia distinctly incurved in preapical part; its inner margin with distinct granules spiniform in apical half. Hind tibia flat on outer surface at level of corbel; process of inner apical angle long, slightly shorter than 1st–3rd segments of hind tarsus combined, 1.3 times as long as 2 basal segments. 2nd segment of fore tarsus weakly elongate, 1.17 times as long as wide; 1st segment of hind tarsus 2.07 times, and 2nd segment 1.27 times as long as wide.

Venter slightly longer than wide, 2.16 times as wide as intercoxal process of ventrite I; ventrite I moderately depressed; ventrite V convex at sides of wide median depression.

Penis 1.2 times as long as apophyses; lamella of penis nearly subulate apically, 1.5 times as long as, or slightly shorter than wide; ostial plate not projecting beyond contour of lamella, 0.48 times as long as lamela.

Vestiture yellowish gray with weak metallic sheen. Recumbent lanceolate scales on pronotum and elytra similar, 5–7 times as long as wide; setiform hairs distinct on tubercles and apical elytral declivity. Pronotum laterally with ill-defined longitudinal pale bands in median 1/3; elytra usually with distinct transverse pale band before apical declivity; lateral surface of pronotum and elytra with distinct vestiture.

Body length 8.2–8.4 mm, width 4.0–4.3 mm; those in holotype 8.4 and 4.3 mm, respectively.

Female. Pronotum 1.25–1.35 times as wide as long, with narrow superficial median sulcus on disc. Elytra 1.25 times as long as wide. Fore tibia considerably widened toward apex, slightly incurved in preapical part. Hind tibia with distinct granules on inner margin along entire length.

Body length 8.2–8.9 mm, width 4.5–4.8 mm.

Comparative diagnosis. Stiltoblosyrus longipes sp. n. clearly differs from most of the congeners in a long process of the inner apical angle of the male hind tibia and in a subulate apex of the aedeagus. The process of the apex of the male hind tibia is shorter than that in S. titanicus sp. n. and longer than that in S. zhangi sp. n. The new species also differs from S. titanicus sp. n. in a flattened elytral disc and in a subulately attenuate lamella of the penis. In contrast to those in S. zhangi sp. n., the outer margin of the male hind tibia is flat at the level of the corbel, and the ostial plate does not project beyond the contour of the lamella of the penis.

Etymology. The name of the new species is a Latin invariable adjective formed by “longus” (long) and “pes” (a leg).

Stiltoblosyrus zhangi Davidian, sp. n. (Fig. 4, 2; Fig. 5, 7; Fig. 7, 1, 2)

Material. Holotype: ♂, China, Yunnan Prov., divide between Mekong and Yangtze rivers, ESE of Xiacun, SSW of Ana Yakegua, 27°42ʹ43ʺN, 99°07ʹ54ʺE, H = 3855 m, 1.VI.2017 (G.E. Davidian). Paratypes: 9 ♂, 3 ♀, as holotype; same locality, 4.8 km ENE of Wadang, 27°49ʹ09ʺN, 99°07ʹ51ʺE, H = 3965 m, 4.VI.2017 (G.E. Davidian), 4 ♂; same locality, Mekong Valley, ENE of Yezhixiang, NE of Houqing, 27°42ʹ53ʺN, 99°06ʹ29ʺE, H = 3650 m, 30.V.2017 (G.E. Davidian), 5 ♂, 2 ♀.

Description. Male. Rostrum narrowed toward apex, 1.32 times as wide as long. Rostral dorsum distinctly compressed laterally in middle, rounded laterally in apical half. Head at level of eyes 1.48 times as wide as frons. Length of antennal scape equal to, or slightly exceeding width of rostrum at antennal insertion. 2 basal funicular antennal segment equal in length, or 1st slightly shorter; 2nd segment 2.73 times as long as wide; 3rd–6th segments similarly elongate, half as long as 2nd segment; 7th segment widest, 1.33 times as long as wide; club of antenna fusiform, widest at midlength, 2.18 times as long as wide, with lateral margins straight in basal half.

Fig. 5.
figure 5

Stiltoblosyrus gen. n., aedeagus dorsally (1–17), ovipositor (18), spiculum ventrale (19), and spermatheca (20): (1, 18–20) S. belousovi sp. n., (2) S. laticollis sp. n., (3) S. brevicornis sp. n., (4) S. vulgaris sp. n., (5) S. gracilis sp. n., (6) S. delavayi sp. n., (7) S. zhangi sp. n., (8) S. fairmairei sp. n., (9) S. pulcher sp. n., (10) S. kabaki sp. n., (11) S. lisu sp. n., (12) S. curvimanus sp. n., (13) S. andreii sp. n., (14) S. longipes sp. n., (15) S. titanicus sp. n.; (16) S. asyae sp. n.; (17) S. khalidi sp. n.

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Pronotum widest distal to midlength, 1.33–1.38 times as wide as long; disc with numerous granules and with several tubercles.

Elytra oblong-oval, subparallel-sided in middle part, 1.24 times as long as wide; tubercle at base of 5th interstria slightly projecting beyond contour of slanting humeri. Sutural and even-numbered interstriae with vague rows of very small granules smaller than those on pronotum.

Fore tibia distinctly incurved in preapical part. Hind tibia distinctly, nearly cariniform convex on outer surface at level of corbel; process of inner apical angle slightly longer than 1st and 2nd segments of hind tarsus combined. 2nd segment of fore tarsus as long as wide or elongate; 1st segment of hind tarsus 2.33 times, and 2nd 1.54 times as long as wide, slightly longer than 3rd segment.

Venter slightly elongate, 2.16–2.2 times as wide as intercoxal process of ventrite I; ventrite I weakly depressed; ventrite V rounded apically, with round median depression in apical half.

Penis 1.65 times as long as apophyses; lamella of penis elongate, subulate apically, 1.73 times as long as penis tube; ostial plate more than half as long as lamella, clearly projecting beyond its contour.

Vestiture copper-colored with weak metallic sheen, formed by recumbent lanceolate scales and setiform obliquely erect hairs pointed apically and most distinct on apical elytral declivity. Scales on pronotum narrower than those on elytra; sides of pronotum and elytra with distinct vestiture.

Body length 7.1–8.5 mm, width 3.5–4.4 mm; those in holotype 8.0 and 4.1 mm, respectively.

Female. Pronotum 1.47 times as wide as long. Elytra 1.18–1.30 times as long as wide. Fore tibia weakly widened toward apex, slightly incurved in preapical part. Ventrite I convex; ventrite V flat, widely triangular, narrowly rounded apically.

Body length 7.3–8.0 mm, width 3.85–4.60 mm.

Comparative diagnosis. Stiltoblosyrus zhangi differs from most of the congeners in a large process at the apex of the male hind tibia. The new species is most closely related to S. titanicus sp. n. and S. longipes sp. n. but differs in a smaller body, in the outer side of the male hind tibia strongly convex at the level of the corbel, in a shorter process of its inner apical angle, and also in the ostial plate noticeably projecting beyond the contour of the penis.

Biology. The insects were collected at night by beating rhododendron and currant branches.

Etymology. The new species is named after Dr. Runzhi Zhang (IZCAS, Beijing), the leading Chinese expert on weevils. Noun in genitive, invariable.

Fig. 6.
figure 6

Habitats of Stiltoblosyrus gen. n.: (1, 2) S. andreii sp. n.: 6.4 km ENE of Weixi City, SW of Guoditang, 3235 m; (3) S. brevicornis sp. n. Diancan Shan, 0.8 km ENE of Mt. Wutaifeng, 3665 m; (4) S. curvimanus sp. n.: mountain 4.2 km E of the Lidima Vill., 4100 m.

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Stiltoblosyrus titanicus Davidian, sp. n. (Fig. 4, 3; Fig. 5, 15)

Material. Holotype: ♂, China, Yunnan Prov., Laojunshan Mts., NE of Liming, 4.2 km S of Muzhengdu, 27°06ʹ34ʺN, 99°45ʹ03ʺE, H = 3695 m, 3.VI.2016 (G.E. Davidian). Paratypes: 1 ♂, 1 ♀, as holotype. The holotype lacks the apex of the left middle tibia and the tarsus.

Description. Male. Rostrum slightly transverse, 1.07 times as wide as long, weakly converging from base to apex, subparallel-sided before apex. Rostral dorsum compressed laterally in middle, parallel-sided in apical half. Head at level of eyes 1.5 times as wide as frons. Length of antennal scape 1.11 times width of rostrum at antennal insertion; 1st funicular antennal segment slightly wider and 0.82 times as long as 2nd one; 2nd segment 4 times as long as wide; 3rd–6th segments similar, weakly elongate, 0.3 times as long as 2nd segment; 7th widest, 1.2 times as long as wide; club of antenna fusiform, widest at midlength or slightly distal, 2.17 times as long as wide, with lateral margins straight in basal half.

Pronotum widest distal to midlength, 1.28 times as wide as long, slightly compressed laterally in basal half, with small granules and rather large tubercles on disc.

Elytra oblong-oval, rather strongly convex in transverse direction, 1.42 times as long as wide; tubercle at base of 5th interstria not projecting beyond contour of slanting humeri.

Fore tibia distinctly incurved in preapical part; hind tibia slightly convex on outer surface at level of corbel. Process of inner apical angle of hind tibia very long, widest in apical half, slightly longer than hind tarsus. 2nd segment of fore tarsus 1.14 times as long as wide; 1st segment of hind tarsus 2.28 times, and 2nd 1.54 times as long as wide.

Venter slightly elongate; ventrite I weakly depressed; ventrite V with distinct wide median depression nearly along entire length, with moderately widely rounded apex.

Apophyses 1.24 times as long as penis. Lamella of penis in the form of equilateral triangle or slightly elongate, subequal in length to penis tube; ostial plate several times shorter than lamella, not projecting beyond its contour.

Recumbent lanceolate scales 7 times as long as wide, subequal in size on pronotum and elytra; setae in elytral striae slightly shorter and narrower than scales; obliquely erect setiform hairs on elytral interstriae longer, most distinct on apical declivity. Lateral surface of pronotum and elytra with distinct vestiture.

Body length 8.5–8.9 mm, width 4.0 mm; those in holotype 8.9 and 4.0 mm, respectively.

Female. Frons convex in middle part, with distinct median sulcus. Head at level of eyes 1.45 times as wide as frons. Pronotum with fine median sulcus. Elytra widely oval, slightly convex laterally, 1.25 times as long as wide; disc considerably depressed along 2 first interstriae. All tibiae with uniform dentiform mucro. Fore tibia distinctly widened toward apex, slightly incurved inward in preapical part; hind tibia with dense spines on inner margin. 2nd segment of fore tarsus slightly elongate; 1st segment of hind tarsus twice as long as wide, 1.33 times as long 2nd one; 2nd segment 1.64 times as long as wide. Venter 2.33 times as wide as intercoxal process of ventrite I; ventrite I convex. Ramus of spermatheca entirely recumbent to cornu, nearly half as wide as it.

Body length 8.7 mm, width 4.65 mm.

Comparative diagnosis. Stiltoblosyrus titanicus differs from all the congeners in a very long (longer than the hind tarsus) process at the apex of the hind tibia of the male. The new species is most closely related to S. longipes sp. n. but differs in a larger body, in transversely convex elytra, and in a triangular lamella of the penis. The female of the new species hardly differs from the co-occurring S. kabaki sp. n. in prominent eyes, in the frons convex in the middle part, and in the fore tibia clearly widened toward the apex.

Biology. The insects were collected at night by beating rhododendron branches.

Etymology. The name of the new species is a Latin masculine adjective formed by “Titans,” descendants of the gods Uranus and Gaia in the Ancient Greek mythology.

Stiltoblosyrus asyae Davidian, sp. n. (Fig. 4, 4; Fig. 5, 16; Fig. 7, 3)

Material. Holotype: ♂, China, Yunnan Prov., N of Lijiang, W of Maguwa, 4.2 km SE of Shanggaohan Vill., 27°26ʹ33ʺN, 100°19ʹ27ʺE, H = 4055 m, 24.V.2017 (G.E. Davidian). Paratypes: 14 ♂, 12 ♀, as holotype; W of Bengluo Vill., 27°25ʹ47ʺN, 100°19ʹ57ʺE, H = 3635 m, 23.V.2017 (G.E. Davidian), 1 ♂.

Description. Male. Integument mainly matte. Rostrum almost entirely parallel-sided; rostral dorsum distinctly compressed laterally, parallel-sided in apical 2/3. Eyes strongly convex, most convex slightly behind middle; head at level of eyes at 1.43–1.52 times as wide as frons. Length of antennal scape slightly exceeding width of rostrum at antennal insertion; 1st funicular antennal segment slightly wider and shorter than 2nd segment; 2nd segment 3.14 times as long as wide; 3rd and 4th segments slightly elongate; 5–7th nearly round; 7th segment widest; club slightly compressed laterally in basal half, 2.12 times as long as wide.

Fig. 7.
figure 7

Habitats of Stiltoblosyrus gen. n.: (1, 2) S. zhangi sp. n.: ESE of Xiacun, SSW of Ana Yakegua, 3855 m; (3) S. asyae sp. n.: W of Maguwa, 4.2 km SE of Shanggaohan Vill., 4055 m; (4) S. khalidi sp. n.: northwestern slope of Mt. Yulongxueshan, 4005–4125 m.

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Pronotum strongly transverse, widest distal to midlength, 1.41 times as wide as long; disc swollen, with numerous granules and several large, slightly smoothened tubercles; sides with large granules.

Elytra weakly elongate, 1.17 times as long as wide. Elytral interstriae 2.5–3.0 times as wide as striae. Even-numbered and sutural interstriae with shining granules similar in size to, or larger than punctures in striae. Large tubercles on 3rd, 5th, and 7th elytral interstriae usually as wide as interstriae, forming transverse row before apical apical declivity. Distance between 2 large tubercles in apical part of 5th interstria noticeably shorter than that between last of them and small tubercle at place of merging of 3rd and 9th interstriae.

Fore tibia incurved in apical part, with S-shaped inner margin; hind tibia straight; articular surface slightly widened toward place of attachment of tarsus in lateral view, with rounded outer margin. Inner margin of tibia with distinct granules part of which spiniform. Articular surface on hind tibia with distinct carina between place of attachment of tarsus and outer margin of corbel; process of inner apical angle widened in apical half, narrowly rounded apically, with ledge on ventral side before widening, 1.3–1.4 times as long as 1st segment of hind tarsus. 2nd segment of fore tarsus as long as wide; 1st segment of hind tarsus 2.17 times, and 2nd 1.35 times as long as wide.

Venter 2.07 times as wide as intercoxal process of ventrite I; ventrite I depressed; ventrites II–IV combined nearly as long as ventrite V; ventrite V weakly convex, with wide superficial median depression, rounded apically, slightly emarginate apically in medial 1/3.

Penis convex laterally in middle part; lamella of penis distinctly narrowed toward apex, obtused at end, with small median emargination; ostial plate horseshoe-shaped, not projecting beyond contour of lamella. Apophyses equal in length to penis.

Vestiture of body slightly spotty, brownish-gray without metallic sheen, occasionally with transverse pale band before apical declivity; sides of elytra with distinct vestiture; lower half of apical declivity usually with denser copper-colored vestiture. Lanceolate recumbent scales on elytra 4–6 times as long as wide, slightly longer than obtused setae in elytral striae, 0.33–0.50 times as long as the obliquely erect setiform hairs on interstriae. Scales on pronotum slightly narrower. In setal comb along outer margin of corbel on hind tibia, longer arcuately curved setae in proximal part hanging over shorter straight setae in its distal part.

Body length 7.2–9.15 mm, width 3.9–4.6 mm; those in holotype 8.55 and 4.53 mm, respectively.

Female. Rostrum slightly narrowed toward apex, considerably widened at base. Rostral dorsum parallel-sided in apical half. 3rd and 4th funicular segments of antenna round or slightly elongate; 5–7th segments round. Pronotum transverse, widest distal to midlength, 1.48–1.65 times as wide as long, with widely rounded and occasionally almost angularly convex sides. Elytra widely oval, 1.17 times as long as wide. Outer margin of fore tibia straight; outer apical angle slightly widened. Hind tibia straight, widened outward apically; its inner margin with numerous granules part of which spiniform. Venter 2.15 times as wide as intercoxal process of ventrite I.

Body length 8.0–9.3 mm, width 4.6–5.3 mm.

Comparative diagnosis. Stiltoblosyrus asyae differs from all the congeners in a distinct carina on the articular surface of the hind tibia of the male between the place of attachment of the tarsus and the outer margin of the corbel. The new species is very closely related to S. khalidi sp. n. but differs as follows: in lateral view, the articular surface of the hind tibia of the male is slightly widened toward the place of attachment of the tarsus; the outer margin of the corbel is rounded; the setal comb along the outer margin of the corbel in the proximal part consisting of longer, arcuately curved setae hanging over the shorter straight setae in the distal part; the armament of the endophallus is formed by uniform small spicules.

Biology. The insects were collected at night by beating branches of bushy rhododendron.

Etymology. The new species is named after my daughter Аsya Genrikhovna Davidian who helped me in collecting. Noun in genitive, invariable.

Stiltoblosyrus khalidi Davidian, sp. n. (Fig. 5, 17; Fig. 7, 4)

Material. Holotype: ♂, China, Yunnan Prov., N of Lijiang, northwestern slope of Mt. Yulongxueshan, from 27°07ʹ32ʺN, 100°07ʹ57ʺE to 27°07ʹ52ʺN, 100°08ʹ36ʺE, H = 4125–4005 m, 7.VII.2007 (I.A. Belousov, I.I. Kabak).

Description. Male. Rostrum slightly narrowed toward apex, considerably thickened at base, 1.07 times as wide as long. Rostral dorsum compressed laterally, parallel-sided in apical half. Antennal scape slightly shorter than width of rostrum at antennal insertion; 1st funicular antennal segment 0.83 times as long as 2nd one; 2nd segment 2.67 times as long as wide and 2.18 times as long as 3rd one; 3rd and 4th segments similarly weakly elongate; 5th and 6th segments slightly elongate; 7th segment round, 1.2 times as wide as 6th. Club widely fusiform, widest distal to midlength, 2.2 times as long as wide, as long as 4–7th segments combined, with lateral margins straight in basal half.

Pronotum 1.56 times as wide as long.

Elytra 1.16 times as long as wide and 1.4 times as wide as pronotum. Sutural and even-numbered interstriae with distinct round granules subequal in size to punctures in elytral striae.

Fore tibia distinctly incurved in apical part, with S-shaped inner margin. Hind tibia nearly straight along outer margin; apical part of inner margin smooth, without granules; articular surface in lateral view distinctly narrowed to place of attachment of tarsus; outer margin of corbel truncate. Articular surface of hind tibia with inconspicuous carina between place of attachment of tarsus and outer margin of corbel. Process at apex of hind tibia slightly longer and narrower than 1st segment of hind tarsus, 1.6 times as long as 2nd segment. 2nd segment of fore tarsus triangular, as long as wide; 1st segment of hind tarsus 2.1 times as long as wide; 2nd segment 1.41 times as long as wide, 0.65 times as long as 1st segment.

Venter slightly transverse, 1.95 times as wide as intercoxal process of ventrite I; ventrite V rather widely truncate apically, with round median depression in apical half.

Penis and apophyses of aedeagus subequal in length; penis tube subparallel-sided, noticeably longer than lamella. Lamella of penis narrowed toward apex, slightly rounded at end, with small median emargination; ostial plate elongately horseshoe-shaped, slightly longer than lamella. Endophallus with numerous punctiform sclerites, with 2 arcuately curved sclerites at base of apophyses.

Vestiture mainly brown without metallic sheen, paler in lower half of apical elytral declivity. Lanceolate recumbent scales on elytra subequal in size to paler setae in elytral striae, 0.40–0.67 times as long as the erect setiform hairs most distinct on tubercles and apical elytral declivity. Pronotum with narrower scales and hairs. Setal comb along outer margin of corbel on hind tibia consisting of uniform straight setae.

Body length of holotype 6.8 mm, width 3.7 mm.

Female unknown.

Comparative diagnosis. Stiltoblosyrus khalidi is very similar to S. asyae sp. n. but differs in a smaller body, in the presence of 2 small arcuately curved sclerites in the endophallus at the level of the base of the apophyses, and also in the structure of the hind tibia: in lateral view, its apical part is smoothly narrowed toward the place of attachment of the tarsus, the carina on the articular surface of the hind tibia is inconspicuous, the apical comb consisting of uniform straight setae, and the process of the inner apical angle is shorter.

Etymology. The new species is named after my comrade and colleague Khalid Aliev, an expert on Hymenoptera (Apoidea). Noun in genitive, invariable.

Key to the Species of the Genus Stiltoblosyrus gen. n. (mainly based on the characters of the male)

1 (2). Antennal scape short, its length 0.81 times width of rostrum at antennal insertion. Elytra widely oval, with ill-defined tubercles on 3rd and 5th interstriae, without tubercles on 7th interstria. Tibiae straight, slender, long; process of inner apical angle of hind tibia of male obtused apically, with small tooth ventrally, slightly shorter than 2nd segment of hind tarsus ........ S. vulgaris sp. n.

2 (1). Length of antennal scape slightly exceeding or equal to width of rostrum at antennal insertion. Elytra subparallel-sided or slightly convex in middle part, with large tubercles on 3rd, 5th, and 7th interstriae. Fore tibia of male S-curved or incurved in apical part; process of inner apical angle of hind tibia usually long, but occasionally short.

3 (4). Pronotum regularly rounded laterally, widest near midlength. Hind tibia of male deeply emarginate on inner margin before corbel, truncate apically in both sexes; process of inner apical angle slightly wider than, and 1.25 times as long as 1st segment of hind tarsus. Sides of pronotum and elytra nearly glabrous ........ S. lisu sp. n.

4 (3). Pronotum widest considerably distal to midlength, strongly narrowed toward base. Hind tibia not emarginate on inner margin before corbel in male, more or less rounded apically in both sexes. Sides of pronotum and elytra usually with distinct vestiture, occasionally with sparse scales.

5 (6). Distance between 2 large tubercles in apical part of 5th interstria distinctly exceeding that between posteriormost of them and small tubercle at place of merging of 3rd and 9th interstriae. Frons strongly convex in medial part, separated from eyes by noticeable depressions. Fore tibia of male S-curved; hind tibia of male strongly flattened laterally, curved dorsoventrally along entire length, finely sulcate dorsally in basal half, with ventral margin nearly blade-shaped and forming angular projection near base. Articular surface behind place of attachment of tarsus with long sword-shaped process directed backwards and equal in length to 2 basal tarsal segments combined. 1st segment of hind tarsus of male strongly elongate, 3.1 times as long as wide ........ S. andreii sp. n.

6 (5). Distance between 2 large tubercles in apical part of 5th interstria usually noticeably shorter than that between posteriormost of them and small tubercle at place of merging of 3rd and 9th interstriae. Frons usually weakly convex in medial part. Fore tibia of male more or less incurved in apical part, rarely S-curved. Hind tibia of male rounded in cross-section; process of inner apical angle directed anteriorly, rounded, obtused, or slightly pointed apically.

7 (8). Fore and hind tibiae of male strongly incurved in slightly more than apical 1/3; inner margin of hind tibia smooth in apical half, without granules; process of inner apical angle half as long as 1st, and slightly shorter than 2nd segment of hind tarsus. Ventrite V of male with round deep depression in apical half. Elytra with bright pale transverse band of scales before apical declivity ........ S. curvimanus sp. n.

8 (7). Fore tibia of male moderately incurved near apex, rarely S-shaped; hind tibia straight or slightly curved in apical part. Inner margin of hind tibia of male distinctly granulate or smooth in apical half; process of inner apical angle usually long, less frequently short, occasionally triangular. Ventrite V of male with superficial depression. Elytra before apical declivity with or without pale band of scales.

9 (12). Process at apex of hind tibia of male shorter than 2nd segment of hind tarsus. Vestiture of dorsal side mainly formed by wide-lanceolate scales. Lamella of penis widely obtused or rounded apically.

10 (11). Rostrum distinctly narrowed toward apex. 2nd funicular segment 3.6 times as long as wide, noticeably longer than 1st segment. Process at apex of hind tibia of male bifurcate apically, noticeably shorter than 2nd segment of hind tarsus. Ventrite V narrowly rounded apically. Lamella of penis distinctly narrowed toward apex and obtused. Sides of elytra with distinct vestiture ........ S. laticollis sp. n.

11 (10) Rostrum slightly narrowed toward apex or parallel-sided in apical half. 2nd funicular segment 1.75–2.25 times as long as wide, slightly longer or shorter than, or as long as 1st segment. Process at apex of hind tibia of male slightly shorter than 2nd tarsal segment. Ventrite V of male widely rounded apically. Lamella of penis widely rounded apically. 10th elytral interstria nearly glabrous ........ S. brevicornis sp. n.

12 (9). Process at apex of hind tibia of male longer than 2nd segment of hind tarsus. Vestiture mainly formed by long lanceolate and hair-like, rarely wide-lanceolate scales. Lamella of penis triangular, occasionally subulate, obtused or rounded apically.

13 (18). Process at apex of hind tibia of male noticeably longer, occasionally much longer than 2 basal segments of hind tarsus combined. Lamella longer than wide, triangular or subulate.

14 (15). Process at apex of hind tibia of male widest in apical half, slightly longer than hind tarsus. Elytral disc transversely convex. Lamella of penis triangular, slightly longer than wide ........ S. titanicus sp. n.

15 (14). Process at apex of hind tibia of male shorter than 1st–3rd segments of hind tarsus combined. Elytral disc flattened. Lamella of penis subulate.

16 (17). Hind tibia of male distinctly convex laterally at level of corbel. Process at apex of hind tibia of male slightly longer than 1st and 2nd segments of hind tarsus combined. Ostial plate of penis clearly projecting beyond its contour ........ S. zhangi sp. n.

17 (16). Hind tibia of male flat or slightly convex laterally at level of corbel. Process at apex of hind tibia of male slightly shorter than 1st–3rd segments of hind tarsus combined, 1.3 times as long as 2 basal segments. Ostial plate of penis not or slightly projecting beyond its contour ........ S. longipes sp. n.

18 (13). Process of inner apical angle of hind tibia of male distinctly shorter than 2 basal segments of hind tarsus combined. Lamella of penis triangular, not longer than wide, or with obtused or rounded apex occasionally shallowly emarginate medially.

19 (28). Process of inner apical angle of hind tibia of male considerably narrower than, usually as long as or longer than, occasionally shorter than 1st segment of hind tarsus.

20 (25). Articular surface on hind tibia of male outward of place of attachment of tarsus smooth, without carina; process of inner apical angle not widened toward apex, as long as, or shorter than 1st segment of hind tarsus, occasionally as long as, or longer than 2nd segment. Intercoxal process of ventrite I narrower, 0.42–0.45 times as wide as venter. Ventrite V rounded apically. Vestiture usually brown with golden metallic sheen.

21 (22). Elytra oblong-oval, 1.38 times as long as wide. Large tubercle at base of 5th elytral interstria slightly projecting beyond contour of humeri. Pronotum and elytra with uniform vestiture of uniform lanceolate copper-colored scales with metallic sheen, usually without transverse band before apical elytral declivity. Process of inner apical angle of hind tibia of male pointed, undulate along ventral margin, depressed on outer side at base, equal in length to 2nd, and noticeably shorter than 1st segment of hind tarsus ........ S. belousovi sp. n.

22 (21). Elytra shortly oval, 1.15–1.23 times as long as wide. Large tubercle at base of 5th elytral interstria not projecting beyond contour of humeri. Pronotum with lanceolate recumbent scales mainly narrower than those on elytra. Process of inner apical angle of hind tibia of male obtused or rounded apically, straight or weakly curved along ventral margin, deeply emarginate on outer side at base, as long as, slightly longer, or slightly shorter than 1st segment of hind tarsus.

23 (24). Elytra 1.23 times as long as wide, weakly convex laterally. Humeri with moderately convex tubercle on 7th interstria. Process of inner apical angle of hind tibia of male 1.02–1.19 times as long as 1st, and 1.65–1.76 times as long as 2nd segment of hind tarsus. Apophyses of aedeagus 2.40–2.85 times as long as penis. Lamella of penis 2.37 times as wide as long, with straight sides ........ S. pulcher sp. n.

24 (23). Elytra 1.15 times as long as wide, subparallel-sided in middle part. Slanting humeri with strongly convex tubercle on 7th interstria. Process of inner apical angle of hind tibia of male as long as, or slightly shorter than 1st segment of hind tarsus, 1.34 times as long as 2nd segment. Apophyses of aedeagus shorter, 1.92–1.96 times as long as penis. Lamella of penis 1.7 times as wide as long, convex laterally ........ S. fairmairei sp. n.

25 (20). Articular surface on hind tibia of male with distinct or inconspicuous carina outward of place of attachment of tarsus. Process at apex of hind tibia of male longer than 1st segment of hind tarsus, distinctly widened in apical half. Intercoxal process of ventrite I wider, 0.46–0.51 times as wide as venter. Ventrite V truncate apically. Vestiture usually gray without metallic sheen.

26 (27). Articular surface on hind tibia of male with distinct carina outward of place of attachment of tarsus, slightly widened in lateral view toward place of attachment of tarsus; outer margin of corbel rounded; in proximal part, setal comb along outer margin of corbel consisting of long arcuately curved setae hanging over shorter straight setae in distal part. Process at apex of hind tibia of male 0.85 times as wide and 1.38 times as long as 1st tarsal segment. Armament of endophallus formed by uniform small spicules ........ S. asyae sp. n.

27 (26). Articular surface on hind tibiae of male with inconspicuous carina outward of place of attachment of tarsus; in lateral view, it is smoothly narrowed to place of attachment of tarsus; its setal comb formed by uniform straight setae along entire outer margin. Process at apex of hind tibia of male slightly longer and narrower than 1st segment. Armament of endophallus formed by small spicules, with 2 larger, arcuately curved sclerites at level of base of apophyses ........ S. khalidi sp. n.

28 (19). Process of inner apical angle of hind tibia of male as wide as, or noticeably wider than 1st segment of hind tarsus, clearly shorter than it.

29 (30). Beetles robust, larger (7.6–8.1 mm). Fore tibia of male S-curved. Process of inner apical angle of hind tibia of male longitudinally sulciform concave on outer side, 1.32 times as long as wide, 1.5 times as wide and 0.58 times as long as 1st tarsal segment. 1st segment of hind tarsus 3.35 times as long as wide. Lamella of penis widely rounded ........ S. kabaki sp. n.

30 (29). Beetles more slender, smaller (6.5–7.0 mm). Fore tibia of male straight, incurved in apical part. Process of inner apical angle of hind tibia of male triangular, flat laterally, 1.37 times as long as wide, as wide as, or slightly wider than 1st segment of hind tarsus. 1st segment of hind tarsus 2.5–3.1 times as long as wide. Lamella of penis subtriangular, clearly narrowed toward apex.

31 (30). Head at level of eyes 1.55 times as wide as rostrum at apex. Rostral dorsum rather strongly compressed laterally, subparallel-sided in apical half. Pronotum with basal half compressed laterally. Hind tibia of male with rounded outer apical angle; process of inner apical angle of hind tibia 1.37 times as long as wide, without accessory tooth ventrally near apex, 0.62 times as long as 1st segment of hind tarsus, slightly longer than 2nd segment ........ S. gracilis sp. n.

32 (31). Head at level of eyes 1.69 times as wide as rostrum at apex. Rostral dorsum weakly compressed laterally, gradually narrowed toward apex in distal half. Pronotum with basal half not compressed laterally. Hind tibia of male with strongly slanting outer apical angle; process of inner apical angle 1.37 times as long as wide, with small accessory tooth ventrally near apex, 0.6 times as long as 1st segment of hind tarsus, as long as 2nd segment ........ S. delavayi sp. n.