A New Weevil Genus Closely Related to Dactylotinus Korotyaev, 1996 (Coleoptera, Curculionidae: Entiminae) with New Species from the Sino-Tibetan Mountains

Abstract

A new weevil genus, Eudactylotinus gen. n. closely related to Dactylotinus Korotyaev, 1996 (Entiminae, Blosyrini), is described from China. It differs from Dactylotinus in the following features: the pronotum is widest somewhat distal to the middle, compressed laterally in the basal half, with numerous granules and distinct median carina on the disc; the humeri are slanting, rarely rounded; the male fore tibia is not widened at the apex; the inner margin of the middle tibia is not concave, with spines similar to those on the fore and hind tibiae; the armament of the endophallus usually has no unpaired median postostial grater (MPG) and a pair of spinule clusters (PCS). Five new species are described: Eudactylotinus shangrilensis sp. n. (type species), Eu. muliensis sp. n., Eu. premucronatus sp. n., Eu. silvestris sp. n., and Eu. squamulatus sp. n. A key to the five species is given.

The present communication continues the series of publications dealing with the weevils of the Sino-Tibetan mountains of China (Davidian, 2020, 2021) and provides new data on the wingless mountain weevils closely related to the genus Dactylotinus Korotyaev, 1996.

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 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 designations of the genitalia structures are adopted in the text as used by Davidian (2020, 2021). The penis consists of a flattened penis body with 2 apodemes (= apophyses). The ostium is covered by an ostial plate (sclerotized apical plate). The armament of the endophallus includes the following structures: MPG, the median postostial grater; PAS, a pair of the anterior sclerites; PPS, a pair of the posterior sclerites; PER, a pair of the endophallic rods; PCS, a pair of the spinule clusters at the sides of PPS.

The body length was measured from the anterior margins of the eyes to the apex of the elytra.

The photographs of the genitalia and terminalia were taken from the slides in glycerol using an Axio Imager M-1 Carl Zeiss microscope at the Laboratory of Biological Control of Pests of the All-Russian Institute of Plant Protection, St. Petersburg. All the holotypes are deposited in ZIN, some 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

Genus Eudactylotinus Davidian, gen. n.

Type species Eudactylotinus shangrilensis Davidian, sp. n.

Description. Male. Rostrum slightly narrowed toward apex; rostral dorsum compressed laterally in middle part, with thin median carina and with two smoothened converging carinae extending from antennal insertion to medial 1/3 of frons. Antennal scrobes clearly visible dorsally.

Head with transverse sulcus between rostral dorsum and frons, deepest and widest at mid-length; frons slightly wider than apex of rostrum, usually with narrow median sulcus and with wide depressions along eyes; posterior margin of the depressions slightly raised or roundly prominent near eyes. Eyes dorso-lateral, most convex slightly behind the middle and somewhat turned forward; posterior margins of eyes strongly raised above lateral surface of head. Epistome marginate posteriorly with slightly raised glabrous shining black stripe passing into fine median carina. Length of antennal scape subequal to width of rostrum at antennal insertion. 2nd segment of antennal funicle slightly or distinctly longer than 1st segment; 3rd–7th segments usually rounded or elongate (occasionally 3rd segment weakly elongate whereas the other segments rounded); 7th segment slightly larger than or as large as preceding ones. Club fusiform, widest at midlength, pointed apically.

Pronotum transverse, usually widest distal to middle, compressed laterally in basal half, in widest point 1.19–1.30 times as wide as at base. Disc with distinct granules largest at sides, and with distinct, occasionally smoothened median carina not reaching apex and base.

Elytra subparallel-sided; humeri strongly slanting. Disc flattened or weakly convex, usually passing into sides with distinct bend on 7th interstria. Granules on elytral interstriae usually strongly smoothened, arranged in a confused row. Sutural, and also even-numbered interstriae usually without tubercles. Upper part of apical declivity with distinct tubercles on 3rd, 5th, and, occasionally, on 7th interstriae. In addition, large tubercle situated at apex of 5th interstria; small tubercle present at place of merging of 3rd and 9th interstriae. In basal part of elytra, on 3rd, 5th, and 7th interstriae, tubercles usually wide and weakly convex; in Eu. silvestris sp. n., tubercles developed along entire length of these interstriae. In dorsal view, elytral apex and tubercles on 5th interstria situated nearly in line. Striae narrow, 0.2–0.5 times as wide as interstriae, with small granules on partitions between punctures.

Legs moderately thickened; fore tibia slightly or distinctly incurved in apical part, with distinct spines or with weakly elongate granules along inner margin, with unwidened outer apical angle. Outer margin of apical comb of hind tibia directed distad, not bent inwards. Inner apical angle of tibiae with spiniform mucro; hind tibia with or without premucro. 2nd segment of fore tarsus usually almost as long as wide or distinctly elongate.

Ventrite 5 with deep rounded medial depression along nearly entire length.

Penis body flattened and wide; its dorsal wall membranous, like that in most species of the tribe; ventral wall sclerotized, shorter than apodemes. Lamella of penis very short; apical margin of penis and ostial plate widely rounded or obtused. Apical part of penis (that with sclerotized sides) strongly transverse. Endophallic armament almost symmetrical, with one or two pairs of large sclerites in PAS area and with long PER, which is 1.5–2.0 times as long as apodemes of penis. MPG and PPS present only in Eu. silvestris sp. n.

Body usually with irregular vestiture, with glabrous or nearly glabrous areas; antennae and tarsi with vestiture formed by hair-like setae. Scales usually narrowly lanceolate, occasionally oval, brown or ocherous; subrecumbent setiform hairs on elytral interstriae most cleraly visible mainly on tubercles; punctures in striae with very small setiform hairs. Pale scales forming longitudinal stripes along medial 1/3 of pronotal disc and transverse band before apical elytral declivity. Sides of elytra nearly glabrous or with vestiture sparser than that on disc. Venter with hairs or with very narrow pale or dark brown scales pointed apically.

Female. Elytral humeri slanting or rounded. Fore tibia nearly straight or slightly incurved in apical part. All tibiae with similar mucro, without premucro. Ventrite 5 with distinct oblong superficial depression. Styli on coxites of ovipositor distinctly elongate. Vagina with large oblong-oval sclerotized plate. Lamella of spiculum ventrale slightly wider than long or as long as wide, with numerous hairs at apex. Collum of spermatheca as long as or slightly longer than ramus, weakly widened in apical part.

Comparative diagnosis. The new genus is closely related to Dactylotinus Korotyaev, 1996, sharing with it the following features: the length of the antennal scape is subequal to the width of the rostrum at the antennal insertion; the 1st segment of the antennal funicle is usually shorter than the 2nd segment; ventrite 5 has a deep rounded medial depression along the nearly entire length; the venter is covered with smooth, usually elongate scales; the apical part of the penis with sclerotized sides is strongly transverse; the apical margin of the penis and ostial plate is widely rounded or obtused; the endophallic armament includes large sclerites in the PAS area; PER is distinctly longer than the apodemes.

Comparative diagnoses of the genera Dactylotinus and Eudactylotinus gen. n. are given here in the form of a key. The taxonomic positions of the genera Dactylotinus, Dactylotus Schoenherr, 1847, Kamius Korotyaev, 1996, Nipponoblosyrus Korotyaev, 1996, and Dactylotinomorphus Davidian, 2021 were discussed in Davidian (2021).

Rostrum narrowed toward apex or slightly widened in apical part; rostral dorsum usually without distinctly outlined, smooth and shining black stripe behind epistome. Pronotum widely, almost regularly rounded at sides, widest usually near midlength; disc finely and uniformly punctate, without granules; median carina absent or strongly smoothened and ill-defined. Elytra with widely rounded humeri; interstriae usually without distinct tubercles or with tubercles only in apical part. Elytral disc convex in cross-section, usually smoothly passing into sides, without bend on 7th interstria. Fore tibia of male widened or not widened outwards apically; middle tibia with inner margin slightly or distinctly emarginate in apical half, with row of slanting spines larger than those on fore and hind tibiae; hind tibia without premucro. Ventrite 5 of male with medial part of apical margin usually bordered by notches at sides. Elytra usually with uniform vestiture formed by narrow lanceolate scales and setae. Endophallic armament with MPG, PAS (one pair of sclerites), PPS, and PCS. Collum of spermatheca gradually narrowed toward apex or almost of the uniform width along entire length …….. Dactylotinus Korotyaev, 1996.

—Rostrum narrowed toward apex; rostral dorsum usually with distinctly outlined, raised smooth black stripe behind epistome. Pronotum widest usually distal to middle, considerably compressed laterally in basal half; disc with distinct median carina, with numerous granules and occasionally with tubercles. Elytra with humeri strongly slanting; interstriae with distinct tubercles on 3rd, 5th, and 7th interstriae in apical part or along their entire lengths. Elytral disc flattened or weakly convex, usually passing into sides with distinct bend on 7th interstria. Fore tibia of male not widened at apex; middle tibia with inner margin not emarginate, with spines similar to those on fore and hind tibiae; hind tibia with or without premucro. Ventrite 5 of male usually with smooth apical margin. Elytra usually with nonuniform vestiture formed by narrow lanceolate or oval scales, with small or, occasionally, large glabrous areas. Endophallic armament without PCS, usually also without MPG and PPS, with one or two pairs of sclerites in PAS area. Collum of spermatheca more or less strongly widened in apical part …….. Eudactylotinus gen. n.

Distribution. The new genus is distributed in the Chinese provinces of Sichuan and Yunnan at the altitudes of 2500–4000 m.

Etymology. The name of the new genus is a masculine noun in apposition formed of the Greek prefix “eu” (true) and the name of the genus Dactylotinus.

Eudactylotinus shangrilensis Davidian, sp. n. (Fig. 1, 1; Fig. 3, 2, 6, 7)

Material. Holotype: ♂, China, Yunnan Prov., Tianbaoshan, between Shangri-La and Habaxue Shan, NE of Xiaozhongdian, 27°35ʹ47ʺN, 99°54ʹ34ʺE, H = 4160 m, 21.V.2015 (I.A. Belousov, G.E. Davidian, I.I. Kabak). Paratypes: 7 ♂, 4 ♀, as holotype; same locality, 27°36ʹ00ʺN, 99°54ʹ05ʺE, H = 4015 m, 20.V.2015 (I.A. Belousov, G.E. Davidian, I.I. Kabak), 1 ♀; same locality, SE of Niguge, 27°36ʹ38ʺN, 99°56ʹ13ʺE, H = 4285 m, 22.V.2015 (I.A. Belousov, G.E. Davidian, I.I. Kabak), 2 ♂.

Description. Male. Rostrum transverse, 1.29–1.30 times as wide as long, 1.15 times as wide at base as at apex. Transverse sulcus between frons and rostral dorsum distinct in medial part, considerably not reaching sides. Frons with narrow median sulcus along nearly entire length. Lateral parts of frons with wide depressions, their posterior margin distinctly raised along eyes. Head at level of eyes 1.48–1.58 times as wide as frons.

Length of antennal scape 0.88–0.92 times apical width of rostrum. 2nd funicular segment 1.07–1.10 times as long as 1st and 1.89 times as long as 3rd segment; 3rd–7th segments round or slightly elongate. Club 2.23 times as long as wide.

Pronotum strongly compressed laterally in basal half, 1.43–1.48 times as wide as long, at widest point 1.23–1.25 times as wide as at base; disc almost entirely very finely punctate, with merging granules and with wide distinct median carina.

Elytra subparallel-sided, with strongly slanting humeri, 1.16 times as long as wide, 1.72–1.75 times as wide as pronotum. Striae approximately 0.33–0.40 times as wide as intertstriae; punctures in them slightly differing in size. 5th elytral interstria considerably convex at base; 7th interstria raised along nearly entire length, most clearly visible behind humeri. 3rd and 5th interstriae in upper part of apical declivity with well-developed tubercles subequal in size. Distance from tubercle at apex of 5th interstria to preceding tubercle slightly shorter than or nearly as long as that to small tubercle at place of merging of 3rd and 9th interstriae.

Fore tibia slightly incurved, with inner margin weakly concave in apical half. 2nd segment of fore tarsus weakly transverse, 1.12 times as wide as long.

Venter with nearly isodiametrical microsculpture, finely punctate, with dense small granules; depression on ventrite 5 occupying 0.39–0.40 of ventrite width.

Apical margin of penis and ostial plate widely obtused. Endophallic armament with two pairs of subequally large, simple, acute sclerites in the PAS area; MPG and PPS absent.

Vestiture formed by recumbent, mainly very narrow lanceolate yellowish, pale brown, and pale gray scales, occasionally with weak bluish tint, and also with longer subecumbent setae more distinct on apical declivity. Setae in elytral striae narrow, clearly shorter than scales. Elytra with vestiture most dense on apical declivity, usually with pale transverse band before latter; sides with distinct scales slightly sparser than those on disc.

Body length 5.4–6.0 mm, width 3.20–3.65 mm; in the holotype 5.7 mm and 3.4 mm, respectively.

Female. Posterior margin of depressions on frons along eyes more strongly raised than that in male. Elytra wider, with less strongly slanting humeri. Tubercle at apex of 5th interstria largest; distance from it to penultimate tubercle subequal to distance to the tubercle at place of merging of 3rd and 9th interstriae.

Body length 5.75–6.50 mm, width 3.60–3.95 mm.

Fig. 1.

Eudactylotinus gen. n., male, holotypes: (1) Eu. shangrilensis sp. n., (2) Eu. muliensis sp. n., (3) Eu. premucronatus sp. n., (4) Eu. squamulatus sp. n.

Comparative diagnosis. Eudactylotinus shangrilensis is very similar to Eu. premucronatus sp. n. in habitus and in the structure of the endophallus, but differs in the absence of a premucro on the male hind tibia. It differs from Eu. squamulatus sp. n. in very narrow lanceolate scales on the elytra and in the shape of the distal pair of simple acute sclerites in the PAS area.

Etymology. The name of the new species is derived from that of the Tibetan village of Shangri-La (= Zhongdian) in Yunnan Province of China; this is a noun in apposition, invariable.

Eudactylotinus squamulatus Davidian, sp. n. (Fig. 1, 4; Fig. 3, 3; Fig.4, 1, 2)

Material. Holotype: ♂, China, Yunnan Prov., ENE of Shangri-La, 5.5 km NE of Mizhu, Potatso National Park, 27°54ʹ46ʺN, 99°52ʹ42ʺE, H = 4275 m, 10.VI.2019 (I.A. Belousov, G.E. Davidian, I.I. Kabak). Paratype: ♀, same locality, E of Shangri-La, 3.2 km NE of Hongpocun Vill., 27°50ʹ43ʺN, 99°49ʹ55ʺE, H = 3675 m, 7.VI.2019 (I.A. Belousov, G.E. Davidian, I.I. Kabak).

Description. Male. Rostrum weakly transverse, 1.29 times as wide as long, 1.11 times as wide at base as at apex. Eyes moderately convex; head at level of eyes 1.46 times as wide as frons. Lateral parts of frons with wide depressions; posterior margin of the depressions slightly raised along eyes. Length of antennal scape 0.94 times apical width of rostrum. 2nd funicular segment 1.23 times as long as 1st, and 2.47 times as long as 3rd segment; 3rd–7th segments nearly round; 7th segment widest. Club widely fusiform, 2.53 times as long as wide, with sides straightly converging toward base in basal half.

Pronotum transverse, 1.51 times as wide as long, at widest point 1.25 times as wide as at base, distinctly narrowed toward base and very weakly constricted before it; posterior angles not attenuate and not projecting aside. Disc weakly tuberculate, with numerous granules each bearing a setiferous pore; median carina distinct, rather wide.

Elytra parallel-sided, with strongly slanting humeri, 1.22 times as long as wide and 1.59 times as wide as pronotum. Disc flattened, with distinct, subequal tubercles before apical declivity on 3rd and 5th interstriae. Distance from tubercle at apex of 5th elytral interstria to preceding tubercle clearly shorter than that to tubercle at place of merging of 3rd and 9th interstriae. Basal part of 5th interstria weakly raised; 7th interstria regularly convex along entire length, without tubercles. Elytral striae formed by round punctures 0.33–0.40 times as wide as intertstriae; partitions between punctures subequal to punctures in size.

Fore tibia slightly incurved. Inner margins of tibiae with very short, slanting spiniform granules numerous on fore, and sparser on hind tibia. Hind tibia without premucro. 2nd segment of fore tarsus slightly transverse.

Venter densely covered with small granules, with very fine ill-defined longitudinal folds and with small areas of isodiametrical microsculpture.

Apical margin of penis and ostial plate widely obtused. Endophallic armament in PAS area with two pairs of large sclerites; basal sclerites simple, acute; right distal sclerite three-pointed, and left one, two-pointed; MPG and PPS absent.

Body with vestiture uneven leaving small glabrous areas, with recumbent, narrow and wide, weakly elongate scales, and also with subrecumbent pale brown and grayish yellow setae with weak golden luster. Pronotal disc with pale scales forming 2 longitudinal stripes along medial 1/3. Setae on elytral interstriae at most 1.5 times as long as scales, arranged in one or two (in some places) confused rows; small setae in elytral striae hair-like on glabrous areas and widely lanceolate on densely clothed areas; their length distinctly less than diameter of punctures. Apical declivity almost entirely densely scaled, with transverse pale band before it; sides nearly glabrous.

Body length of holotype 5.8 mm, width 3.3 mm.

Female. Frons with wide deep depressions along eyes; posterior margin of the depressions roundly prominent. Elytra with wide and small scales similar to those in holotype. Female differing from male in widely rounded humeri and also in strongly raised 3rd and 5th interstriae of elytra. Tibiae with more distinct numerous spines on inner margin.

Body length 7.60 mm, width 4.55 mm.

Comparative diagnosis. The new species is most closely related to Eu. shangrilensis sp. n., but differs from it in the vestiture mainly formed by rather wide small scales and also in the endophallic armament with the basal pair of sclerites simple, acute; right of the distal sclerites three-pointed, and left one, two-pointed. From Eu. premucronatus sp. n. and Eu. muliensis sp. n. this species differs in the absence of a premucro on the male hind tibia.

Etymology. The name of the new species is a Latin masculine adjective referring to the vestiture formed by small scales (“squamulae”).

Eudactylotinus premucronatus Davidian, sp. n. (Fig. 1, 3; Fig. 3, 4)

Material. Holotype: ♂, China, Yunnan Prov., W of Lake Lugu, from 27°40ʹ39ʺN, 100°34ʹ20ʺE to 27°40ʹ35ʺN, 100°34ʹ20ʺE, H = 4220–4290 m, 30.V.2012 (I.A. Belousov, G.E. Davidian, I.I. Kabak, A.E. Korolev). Paratypes: 4 ♂, 4 ♀, as holotype.

Description. Male. Rostrum transverse, 1.27–1.33 times as wide as long, 1.10–1.15 times as wide at base as at apex. Head at level of eyes 1.46–1.55 times as wide as frons. Transverse sulcus before frons considerably not reaching sides of rostrum. Frons laterally with wide smooth depressions; posterior margin of the depressions slightly raised. Length of antennal scape 0.92–0.94 times apical width of rostrum. 2nd funicular segment 1.07–1.20 times as long as 1st, and 2.15–2.21 times as long as 3rd segment; 3rd and 4th segments elongate, 1.25 times as long as wide; 5–7th segments usually round. Club widely fusiform, 2.20–2.36 times as long as wide.

Pronotum 1.50–1.55 times as wide as long, at widest point 1.28–1.30 times as wide as at base, moderately compressed laterally in basal half; with basal angles not projecting aside. Disc considerably tuberculate, with distinct median carina, with dense, rather large smoothened granules each bearing a distinct setiferous pore.

Elytra parallel-sided, with strongly slanting humeri, 1.15–1.20 times as long as wide, 1.46–1.62 times as wide as pronotum. Interstriae 2.0–2.5 times as wide as striae, with dense small granules smaller than those on pronotum; punctures in striae slightly varying in size. 3rd and 5th interstriae with well-developed, subequal tubercles before apical declivity. Distance from tubercle at apex of 5th interstria to preceding tubercle shorter than that to small tubercle at place of merging of 3rd and 9th interstriae. 7th interstria mostly weakly convex, most clearly raised behind base.

Fore tibia considerably incurved near apex, S-curved along inner margin, with small slanting spines almost similar to those on middle and hind tibiae. Hind tibia with distinct mucro and premucro equal in size. 2nd segment of fore tarsus slightly transverse.

Ventrite 1 and lateral parts of ventrite 2 with numerous small granules; ventrites 2–5 almost entirely with isodiametrical microsculpture. Depression in central part of ventrite 5 occupying 0.32–0.34 of its width.

Apical margin of penis and ostial plate widely obtused. Endophallic armament with two pairs of large dentiform simple acute sclerites with wide base in the PAS area; MPG and PPS absent.

Elytra with narrow recumbent lanceolate pale brown and yellowish scales, with longer subrecumbent setae on interstriae and with nearly glabrous areas around punctures in elytral striae forming ill-defined mottled pattern. Setae in elytral striae parallel-sided or lanceolate, distinctly shorter than scales. 9th and 10th interstriae with scales sparser in basal half than in apical part. Venter with very narrow recumbent pale scales and with inconspicuous long subrecumbent brown hairs.

Body length 6.0–6.55 mm, width 3.45–3.90 mm; in holotype, 6.45 and 3.60 mm, respectively.

Female. Lateral parts of frons widely and smoothly depressed; posterior margin of depression weakly raised. Spermatheca with wide cornu approximately twice as wide as ramus; сollum widened in apical part, as long as ramus.

Body length 6.2–6.5 mm, width 3.70–3.95 mm.

Comparative diagnosis. Eudactylotinus premucronatus is similar to Eu. shangrilensis sp. n. and Eu. squamulatus sp. n. in the structure of the pronotum and in the sculpture of the elytra, but differs in the posterior part of the frons slightly raised near the eyes and in the male hind tibia with a distinct premucro. In addition, it differs from Eu. squamulatus sp. n. in narrow scales of the vestiture and in the endophallic armament with a distal pair of simple acute sclerites in the PAS area.

Etymology. The name of the new species is a Latin masculine adjective derived from the noun “premucro.”

Eudactylotinus muliensis Davidian, sp. n. (Fig. 1, 2; Fig. 3, 5)

Material. Holotype: ♂, China, Sichuan Prov., S of Muli, 27°43ʹ16ʺN, 101°15ʹ13ʺE to 27°43ʹ03ʺN, 101°15ʹ05ʺE, H = 3975–4120 m, 22.V.2012 (I.A. Belousov, G.E. Davidian, I.I. Kabak, A.E. Korolev).

The holotype lacks claw-segment of the left fore and right hind tarsus; the left antennal funicle is disjointed between the 3rd and 4th segments.

Description. Male. Rostrum weakly transverse, 1.22 times as wide as long, 1.5 times as long as the longitudinal diameter of eye. Epistome nearly as long as wide. Lateral parts of frons widely and smoothly depressed; posterior margin of the depressions slightly raised along eyes. Length of antennal scape 0.98 times apical width of rostrum. 2nd funicular segment 1.25 times as long as 1st, and twice as long as 3rd segment; 3rd and 4th segments subequally elongate, 1.39 times as long as wide; 5–7th segments slightly elongate. Club widely fusiform, twice as long as wide.

Pronotum 1.54 times as wide as long, at widest point (at the midlength) 1.29 times as wide as at base. Sides widely rounded, constricted before base, with projecting posterior angles. Disc with distinct median carina and with weak convex rounded granules each bearing a distinct setiferous pore, with continuous micropunctation in between.

Elytra widely oval, weakly convex at sides, with strongly slanting humeri, 1.1 times as long as wide and 1.54 times as wide as pronotum. Interstriae each with a confused row of small, strongly smoothened granules; sutural and even-numbered interstriae nearly flat; others weakly convex. 5th interstria with weak tubercles in basal half. Upper part of apical declivity with tubercles on 3rd, 5th, and 7th interstriae. Tubercle at apex of 5th interstria largest; distance from it to penultimate tubercle slightly shorter than that to small tubercle at place of merging of 3rd and 9th interstriae. Striae formed by small, sparse punctures, 0.2 times as wide as interstriae; granules on partitions between punctures slightly smaller than those on interstriae.

Fore tibia distinctly bent inwards at apex, with inner margin smoothly convex in middle part and bearing a row of rather large, slanting spines and thickened pointed setae pressed to them. Middle and hind tibiae not widened in middle part, with short spines. Mucrones on fore and middle tibiae subequal in size, slightly larger than that on hind tibia. Hind tibia with distinct lamelliform premucro and with lamelliform attenuate inner apical margin of corbel. 2nd segment of fore tarsus as wide as long.

Venter smooth, with isodiametrical sculpture, weakly lustrous, nearly impunctate and non-granulate; ventrite 5 with wide rounded medial depression.

Penis widely rounded at apex; ostial plate slightly obtused. Endophallus with one pair of large, rather long two-pointed PAS sclerites curved toward each other; left of them slightly more strongly shifted toward apex than right one; MPG and PPS absent.

Vestiture orange-brown, without metallic luster, consisting of recumbent narrow and widely lanceolate scales and also of longer subrecumbent setae condensed along striae. Disc and apical declivity of elytra with similar vestiture, without transverse band; sides of elytra nearly glabrous.

Body length of holotype 6.55 mm, width 4.0 mm.

Female unknown.

Comparative diagnosis. Eudactylotinus muliensis differs from all the congeners in the pronotum widely rounded laterally and with the posterior angles considerably projecting aside and also in the endophallic armament with one pair of large elongate sclerites in the PAS area. In addition, it differs from Eu. silvestris sp. n., Eu. shangrilensis sp. n., and Eu. squamulatus sp. n. in the presence of a premucro on the male hind tibia.

Etymology. The name of the new species is derived from that of the Tibetan village of Muli in Sichuan Province of China; this is a noun in apposition, invariable.

Eudactylotinus silvestris Davidian, sp. n. (Fig. 2; Fig. 3, 1, 8–10)

Material. Holotype: ♂, China, Sichuan Prov., Maoxian–Songpan road, 4.65 km NE of Dadiancun, 31°58ʹ18ʺN, 103°41ʹ55ʺE, 2575 m, 28.VI.2015 (G.E. Davidian). Paratypes: 1 ♂, 1 ♀, as holotype; W of Maoxian, 7.15 km NW of Kekecun, 31°41ʹ33ʺN, 103°44ʹ46ʺE, H = 2435 m, 6.VII.2015 (G.E. Davidian), 1 ♀; northwestern slope of Jiuding Shan, SE of Maoxian, 2.3 km E of Leshicun, 31°38ʹ57ʺN, 103°52ʹ11ʺE, H = 2755 m, 27.VI.2019 (I.A. Belousov, G.E. Davidian, I.I. Kabak), 1 ♀; northwestern slope of Jiuding Shan, E of Maoxian, 3.3 km ESE of Heicitang, 31°39ʹ57ʺN, 103°54ʹ22ʺE, H = 2815 m, 30.VI.2019 (I.A. Belousov, G.E. Davidian, I.I. Kabak), 1 ♀.

Description. Male. Integument mainly matte, with isodiametrical microsculpture, with strongly smoothened granules. Rostrum clearly narrowed toward apex, 1.22–1.25 times as wide as long, 1.11–1.16 times as wide at base as at apex. Transverse sulcus at base of rostrum distinct along entire length, continued onto frons medially in the form of a short fine groove. Eyes strongly convex; head at level of eyes 1.65 times as wide as frons. Lateral parts of frons weakly widely depressed, slightly raised in posterior part along eyes. Length of antennal scape equal to apical width of rostrum. 2nd funicular segment 1.23 times as long as 1st, and 1.86–1.93 times as long as 3rd segment; 3rd–7th segments subequal, distinctly elongate; 3rd segment 2.1 times as long as wide. Club widely fusiform, 2.29 times as long as wide.

Pronotum widest distal to middle, at widest point 1.19–1.30 times as wide as at base and 1.30–1.47 times as wide as long. Disc with smoothened granules in central part and with smoothened median carina.

Fig. 2.

Eudactylotinus silvestris sp. n., male, holotype.

Elytra with slanting humeri, weakly convex laterally, 1.19 times as long as wide, 1.6 times as wide as pronotum. Striae 0.20–0.25 times as wide as interstriae, formed by small, widely spaced punctures. 3rd, 5th, and 7th interstriae with distinct rows of tubercles along entire length; tubercles on 5th and 7th interstriae subequal behind base and before apical declivity; 4th interstria with smaller tubercles. Tubercle at apex of 5th elytral interstria as large as or slightly smaller than penultimate tubercle; distance from it to penultimate tubercle slightly exceeding that to tubercle at place of merging of 3rd and 9th interstriae.

Fore tibia slightly incurved in apical part; inner margin clearly concave in apical half of tibia. Inner margins of middle and hind tibiae strongly convex in middle part, with distinct slanting spines larger than those on fore tibia. Hind tibia without premucro. 2nd segment of fore tarsus elongate.

Venter matte, with entire surface isodiametrically microreticulate and with very small punctures and granules. Ventrite 5 with deep rounded medial depression 0.51–0.54 times as wide as the ventrite.

Apical margin of penis and ostial plate widely rounded, obtused in medial part. Endophallic armament with small MPG and PPS, with two pairs of sclerites in PAS area (sclerites of basal pair dentiform; distal ones rounded apically, each with a row of short teeth slanting outwards).

Dorsal side of body with rather sparse vestiture formed by very narrow and by moderately widened lanceolate yellow scales with weak metallic luster, also with subrecumbent setae on elytral interstriae. Inconspicuous hair-like setae in elytral striae much shorter than diameter of punctures. Scales forming 2 stripes along medial 1/3 of pronotal disc, rather densely covering sides of pronotum and occasionally apical elytral declivity. Large areas on disc and sides of elytra nearly glabrous.

Body length 7.35–7.40 mm, width 4.15–4.25 mm; in holotype, 7.35 and 4.15 mm, respectively.

Female. Posterior part of frons slightly raised along eyes. Elytra 1.75–1.78 times as wide as pronotum. Inner margins of tibiae nearly straight. Ventrite 5 moderately convex, with distinct superficial depression in medial 1/3. Lamella of spiculum ventrale as long as wide, slightly elongate, or transverse. Collum of spermatheca usually undulate, weakly widened distally, distinctly longer than ramus.

Body length 7.1–8.4 mm, width 4.3–5.0 mm.

Fig. 3.

Eudactylotinus gen. n., aedeagus dorsally (1–5), ovipositor (6, 8), spermatheca (7, 9) and spiculum ventrale (10): (1, 8–10) Eu. silvestris sp. n., (2, 6, 7) Eu. shangrilensis sp. n., (3) Eu. squamulatus sp. n., (4) Eu. premucronatus sp. n., (5) Eu. muliensis sp. n.

Comparative diagnosis. Eudactylotinus silvestris differs from the other species of the genus in the following characters: the body is larger; the elytra with rows of large tubercles along the 3rd, 5th, and 7th interstriae; the middle and hind tibiae of the male are clearly widened inward in the middle part, with large slanting spines; the endophallic armament has MPG and PPS.

Etymology. The name of the new species is a Latin masculine adjective meaning “of the forest.”

Fig. 4.

Habitat (1) and presumable host plant (2) of Eudactylotinus squamulatus sp. n.: ENE of Shangri-La, 5.5 km NE of Mizhu, 4275 m.

Key to the Species of the Genus Eudactylotinus gen. n.

1 (2). 3rd–7th segments of antennal funicle rather strongly elongate; 3rd segment 2.1 times as long as wide. Elytra with rows of tubercles on 3rd, 5th, and 7th interstriae; distance from tubercle at apex of 5th interstria to preceding tubercle exceeding that to the small tubercle at place of merging of 3rd and 9th interstriae. Inner margin of middle and hind tibiae of male clearly convex in middle part, with a row of rather thick spines. 2nd segment of fore tarsus elongate. Endophallic armament in the PAS area with two pairs of sclerites; MPG and small elongate PPS present ........ Eu. silvestris sp. n.

2 (1). 3rd–7th funicular segments usually round; if weakly elongate, then 3rd segment 1.39 times as long as wide. 3rd and 5th elytral interstriae usually weakly convex in basal part and with distinct tubercles in apical part. Distance from tubercle at apex of 5th interstria to penultimate tubercle usually shorter than that to the small tubercle at place of merging of 3rd and 9th interstriae. Inner margins of male middle and hind tibiae weakly to inconspicuously convex in middle part, with small spines or granules. 2nd segment of fore tarsus as long as wide or slightly wider than long. Endophallic armament without MPG and PPS, with one or two pairs of sclerites in the PAS area.

3 (4). Pronotum widest at midlength, widely rounded laterally, strongly narrowed before base, with posterior angles considerably projecting aside. Inner margin of fore tibia of male considerably convex in middle part, with rather large slanting spines. Hind tibia of male with lamelliform premucro. Abdomen smooth, with isodiametrical microsculpture, nearly without punctures and granules. Endophallic armament with two sclerites in the PAS area ........ Eu. muliensis sp. n.

4 (3). Pronotum widest distal to middle, clearly compressed laterally in basal half, slightly narrowed before base, with basal angles not projecting aside. Inner margin of fore tibia of male inconspicuously or more distinctly convex in middle part, usually with small slanting spines. Hind tibia of male with or without spiniform premucro. Abdomen on two basal ventrites or entirely with distinct, usually rather dense small granules. Endophallic armament with two pairs of sclerites in the PAS area.

5 (6). Hind tibia of male with distinct spiniform premucro. Frons inconspicuously raised in posterior part along eyes in male and weakly raised there in female. Vestiture formed by narrow lanceolate scales. Abdomen with small distinct granules mainly on two basal ventrites ........ Eu. premucronatus sp. n.

6 (5). Hind tibia of male without premucro. Frons weakly or moderately raised in posterior part along eyes. Vestiture mainly formed by narrow lanceolate or oval scales. Entire abdomen densely covered with small granules.

7 (8). Dorsal vestiture formed by strongly elongate lanceolate scales. Frons of male and female distinctly raised in posterior part along eyes. Endophallic armament with two pairs of large simple acute sclerites in the PAS area ........ Eu. shangrilensis sp. n.

8 (7). Dorsal vestiture formed by narrow and wide lanceolate, occasionally oval scales. Frons weakly raised in posterior part along eyes in male, strongly raised there in female. Endophallic armament with two pairs of sclerites in PAS area: basal sclerites simple, acute; right distal sclerite three-pointed, and left one two-pointed ........ Eu. squamulatus sp. n.