On Chinese Trachyphloeini with description of four new species (Coleoptera, Curculionidae, Entiminae)

Abstract Rhinodontodes alashanensissp. nov., Trachyphloeosoma honzasp. nov., T. jirkasp. nov., and T. martinsp. nov. are described from China, illustrated and compared with similar species. The genus Rhinodontodes and the species Rhinodontodes subsignatus Voss, 1967 and Rhinodontus mongolicus Borovec, 2003 are recorded from China for the first time. Keys to all Chinese genera of Trachyphloeini, and to the Chinese species of Rhinodontodes and Trachyphloeosoma, are provided.


Introduction
The Trachyphloeini Gistel, 1848 is a medium-sized tribe of entimines containing small wingless, terricolous species with body size 1.3-6.8 mm, having limited ability to migrate. They are mostly xerothermophilous, associated with steppe habitats, xeric grasslands, stony or sandy places, ranging to sandy semideserts (Borovec 2009 (Figs 1-4) dark brownish, epistome, mucros, and claws reddish brown, fringe of setae on protibiae yellowish. Appressed scales covering antennae, head, pronotum, elytra and legs, except antennal clubs; scales on elytra oval, wider than long, densely and finely longitudinally striate, very dense, imbricate, six or seven scales across interval width, light brownish on disc with small, irregularly scattered dark brownish and greyish spots and with light greyish stripe along lateral margins, occupying three lateral intervals and very short apical part of elytra. Pronotum and head with rostrum with oval appressed scales standing on their edges and visible only as special structure of narrow short lines, only short flat area behind frons with the same appressed scales as elytra. Semi-appressed elytral setae subspatulate to spatulate, in holotype more slender than in paratypes, approximately as long as half of width of one interval, densely and finely longitudinally striate, creating one regular row on each interval, distance between two setae 2 × length of one seta. Pronotum and head with rostrum with almost identical semi-appressed setae, irregularly scattered, on pronotum transversely directed, on rostrum shorter than on elytra and longitudinally directed. Antennal scapes and femora with semi-appressed setae, funicles, tibiae and tarsi with semi-erect, moderately long setae, prominent from outline. Clubs densely and finely setose.
Rostrum 25) 1.17-1.22 × as long as wide, from base slightly, regularly enlarged apicad with straight sides, at apex only slightly wider than at base. Epifrons at basal third distinctly tapered apicad, then weakly enlarged apicad, in both parts with slightly convex sides, at apex distinctly narrower than at base, longitudinally shallowly depressed. Epistome long and conspicuous, distinct in dorsal and lateral view, as wide as apex of rostrum or slightly wider, separated from frons by very narrow carina, in females U-shaped, slender, lengthily exceeding anterior rostral margin, with tips directed anteriad, in males V-shaped, wider, less exceeding anterior rostral margin, with tips directed obliquely, laterally. Frons flat, squamose, bearing in lateral parts four or five pairs of stout apical setae, obliquely directed anteriad. Scrobes in dorsal view visible in apical third of rostrum as narrow furrows; in lateral view narrow, subparallel-sided, weakly curved, directed towards middle of eyes, visible as short furrow only in apical half of rostrum, in basal half with margins weakly indicated. Rostrum in lateral view somewhat convex, separated from head by shallow transverse depression. Eyes almost flat, hardly prominent from outline of head. Head distinctly enlarged basad.
Antennae slender; scapes faintly regularly curved, approximately equally long as funicles, at basal two thirds weakly and regularly enlarged apicad, at apical third enlarged somewhat more, at apex equally wide as clubs. Funicles with segments 1 and 2 conical, long, funicle segment 1 slightly longer and wider than segment 2, in males more slender than in females; in males funicle 1 1.7-1.8 × as long as wide; segment 2 1.8-1.9 × as long as wide; segment 3 1.1 × as long as wide; segments 4 and 5 isodiametric; segment 6 1.1 × as wide as long; segment 7 1.4 × as wide as long; in females funicle 1 1.7-1.8 × as long as wide; segment 2 1.6-1.7 × as long as wide; segment 3 and 4 1.2 × as wide as long; segment 5 1.3 × as wide as long; segment 6 1.4 × as wide as long; segment 7 1.6 × as wide as long.
Penis (Fig. 26) short and wide, 1.91 × as long as wide, in ventral view at base and at apex approximately equally wide, parallel-sided with slightly concave sides; apex regularly rounded to small, regular triangular prolongation; in lateral view wide, regularly curved, subcrescent-shaped, with slender and short apical elongation.
Biology. Unknown. Distribution. China, Inner Mongolia (Fig. 52). Etymology. Patronymic, name is derived from the name of type locality. Differential diagnosis. Rhinodontodes alashanensis is similar to the only other known species of the genus, R. subsignatus Voss, 1967. It is possible to distinguish the two species by the following key: 1 Larger body size, 4.5-5.4 mm. Epistome short, with points narrower than rostrum at apex, in females V-shaped, moderately robust, slightly exceeding anterior margin of rostrum   Voss, 1967 Figs 5-8, 27, 29, 52 Rhinodontodes subsignatus Voss, 1967: 277 (original  Remarks. The eighteen specimens examined of R. subsignatus come from Mongolia and also from China, Inner Mongolia Autonomous Region. The four males and 11 females from China differ somewhat from the three females from Mongolia, which share with the holotype slender, subparallel-sided, semi-erect elytral setae, while material from Mongolia has wider, subspatulate, semi-appressed elytral setae. Mongolian and Chinese specimens are almost identical in all other characters thus we assume the shape of elytral setae is a variable character of the species. This is the first record of R. subsignatus from China (Fig. 52). Remarks. The genus is well defined and distinguished by apex of protibiae strikingly enlarged laterally, armed with wide spines, epistome long, rostrum short and wide, distinctly enlarged before eyes and body wide and robust. It was described as monotypic by Faust (1890) and studied later by Voss (1967) and Borovec (2003). Rhinodontus currently contains five valid species from China and Mongolia (Alonso-Zarazaga et al. 2017). Among material from IZCAS and ZIN we discovered specimens which add to our knowledge distribution of the species, which were previously known from only a limited number of specimens. Remarks. This species was described based on three females from China, Xinjiang and Gansu. This is the first additional locality since the original description.

Rhinodontus crassiscapus
Rhinodontus crassiscapus differs from all other species of the genus by its very short, distally thickened scape and by its long raised elytral setae being longer than one half of the interval width.

Remarks.
Nine females from China (Inner Mongolia) have the spermatheca with a shorter ramus and more slender collum and nine spines at the protibial apex in comparison with previously known material, including the type specimens, of the species having only eight spines. Due to the lack of males of this population we currently retain it as conspecific with R. ignarus. Borovec, 2003 Figs 13, 14, 33, 53 Rhinodontus mongolicus Borovec, 2003 Remarks. The species was described based on 17 females from Mongolia, Ulaan Baatar and these are the first additional specimens since the original description. This is also the first record of the species in China (Fig. 53). Rhinodontus mongolicus is very easy distinguishable from all other species of Rhinodontus by the prominent sulci covering eyes in dorsal view and by the slender antennal scape. Voss, 1967 Figs 15, 16, 34 Rhinodontus proximus Voss, 1967: 275 (original  Remarks. This species was described from four specimens from two localities in Mongolia, later recorded also from China. It is very similar to R. ignarus, but differs by possessing eight or nine spines at apex of protibia, tarsal claws connate only in the very short basal part, and also the more slender antenna. Borovec, 2003 Figs 17, 18, 35 Rhinodontus sawadai Borovec, 2003: 40 (original description Remarks. This species was described based on three females from China, Xinjiang; this is the first additional specimen since the original description. Rhinodontus sawadai can be distinguished from other species of the genus by its wider rostrum, curved scape, missing prominences above eyes, and less enlarged outside apex of protibia. Remarks. This genus was described by Wollaston based on material from the island of St. Helena. Additional species were described later, and the present number of valid species is five. The genus was redescribed and compared to all other Palaearctic Trachyphloeini by Borovec (2009), then subsequently revised by Borovec (2014), based on material from China, Vietnam, Japan, Korea, and the Moluccas. Morimoto (2015), in his monography of Japanese Entiminae, surveyed the Japanese species of the genus. China is the most northwestern part of the range of the genus, and Trachyphloeosoma was first recorded from this country only in 2009 by Borovec, based on one male from Yunnan, and subsequently by Borovec (2014)  Body (Figs 19,20) unicoloured piceous brown, antennae and legs slightly paler, reddish brown. The entire body except for frons, antennal funicles with clubs and tarsi covered with a brownish earth-like incrustation which conceals most of the surface; rounded appressed scales, covering the whole body, very hardly visible through this incrustation. Elytra with one conspicuous, dense row of erect, subspatulate setae on each interval, starting just from the base; setae approximately as long as half width of one interval, slightly enlarged apicad, distance between two setae slightly longer than length of one seta. Pronotum and head with rostrum with similar setae, less than half as long as elytral ones, densely irregularly scattered, anteriorly directed. Antennal scapes, femora and tibiae with long, erect, very slender setae, distinctly prominent from outline of scapes and legs.

Rhinodontus sawadai
Rostrum (Figs 19,20,36) 1.25-1.31 × wider than long, at base 1.18-1.23 × wider than at apex, evenly tapered anteriad with almost straight sides, at short basal part with shallowly concave sides; in profile short and wide, convex. Epifrons distinctly tapered anteriad with straight sides, at level of antennal insertion narrow, 0.65-0.68 × as wide as corresponding width of rostrum, with ill-defined, shallow, longitudinal furrow. Frons conspicuous, glabrous, smooth and shiny, posteriorly continuous with epifrons. Epistome indistinct. Antennal scrobes in dorsal view fully visible as furrows, reaching eyes; in lateral view with dorsal margin directed towards middle of eye and ventral margin deeply below ventral margin of eye. Eyes small, in dorsal view protruding from outline of head; in lateral view placed in dorsal third, distance from dorsal margin of head longer than diameter of eye.
Penis (Fig. 42) short, 1.57 × as long as wide, subparallel-sided, slightly evenly enlarged apicad, in apical part shortly subtriangular, tip rounded, sides of tip shallowly concave; in lateral view moderately wide, ventral side almost straight, dorsal side irregularly rounded, tip pointed and curved upwards.
Bionomics. The majority of the material was collected by sifting wet debris under trees along the border of an old orchard.
Etymology. The new species is dedicated to one of the collectors and a very good friend of the second author, Dr. Jan Růžička (University of Life Science, Prague). The Czech name Jan has its nickname "Honza". The specific name is a noun in apposition.
Distribution. China, Yunnan (Fig. 54). Differential diagnosis. Trachyphloeosoma honza sp. nov. shares with T. martin sp. nov. short and robust protibiae, short and wide rostrum and subspatulate setae. It is easily distinguished from T. martin sp. nov. by elytral setae on all elytral intervals, dorsal margin of antennal scrobes directed towards middle of eye and female sternite VIII lacking fenestra, while T. martin sp. nov. has elytral setae only on odd intervals, dorsal margin of scrobes directed above dorsal margin of eye and female sternite VIII with longitudinal fenestra. In comparison with non-Chinese species, T. honza sp. nov. is similar to T. advena Zimmerman, 1956, known from Japan, Korea and introduced to U.S.A. and T. ryukyuensis Morimoto, 2015, known from Japan, in the funicle being 7-segmented and body covered by appressed setae and elytra with raised setae on all intervals. It is possible to distinguish T. honza sp. nov. from both by short subspatulate setae, distinctly shorter than width of an elytral interval (long piliform setae on elytra, approximately as long as width of interval in T. advena and T. ryukyuensis), elytral setae distinctly bent backwards in lateral view (perpendicularly erect in T. advena and T. ryukyuensis) and plate of sternite VIII in females without fenestra (with fenestra in T. advena and T. ryukyuensis). Description. Body length: 2.06-2.44 mm, holotype 2.06 mm. Body (Figs 21,22) including antennae and legs unicoloured piceous brown. The entire body except for frons, antennal funicles with clubs and tarsi covered with a brownish earth-like incrustation which conceals most of the surface; appressed scales, covering the whole body, with hardly visible shape, but in lateral parts rounded, finely densely striolate. Elytra with one conspicuous, dense row of long erect setae on each interval, starting from the base; setae as long as width of one interval, very slender, slightly and evenly enlarged apicad, distance between two setae slightly longer than length of one seta. Pronotum and head with rostrum with identically long and shaped setae as elytral setae, densely irregularly scattered, anteriorly directed. Antennal scapes, femora and tibiae with long, erect, very slender setae, distinctly prominent from outline of scapes and legs.

Trachyphloeosoma jirka
Rostrum (Figs 21, 22, 37) 1.12-1.18 × wider than long, at base 1.18-1.20 × wider than at apex, evenly tapered anteriad, at basal half with straight sides; in profile moderately long and slender, convex, at apex distinctly declined. Epifrons in basal half distinctly tapered anteriad, in apical half almost parallel-sided, narrow, 0.61-0.67 × as wide as rostrum in corresponding part, with ill-defined, slender, longitudinal furrow. Frons conspicuous, smooth, shiny, angularly declined from epifrons. Epistome small, short, indistinct, just at apical portion of rostrum, posteriorly narrowly carinate. Antennal scrobes in dorsal view visible as wide furrows, reaching  eyes; in lateral view distinctly subtriangular, strikingly enlarged posteriad with dorsal margin directed above dorsal margin of eye and ventral margin deeply below ventral margin of eye. Eyes small, in dorsal view hardly protruding from outline of head; in lateral view placed subdorsally, distance from dorsal margin of head shorter than diameter of eye.
Pronotum (Figs 21, 22) 1.21-1.28 × wider than long, widest at anterior third, with distinctly rounded sides, slightly constricted behind anterior margin; disc flatly and irregularly granulate, among granules irregularly punctate with rough and fine punctures; in lateral view pronotum slightly convex, anterior margin strongly obliquely directed back beneath towards coxae.
Abdominal ventrites sparsely roughly punctate; ventrite 2 slightly longer than ventrite 1 and distinctly longer than ventrites 3 and 4 combined; suture between ventrites 1 and 2 sinuate, the others straight. Metaventral process as wide as transverse diameter of metacoxa.
Bionomics. This species was collected by sifting in sparse secondary forest.
Etymology. This species is dedicated to Dr. Jiří Hájek, curator of National Museum in Prague, who loaned us very interesting material of Trachyphloeosoma for study and also collected the specimens of this species. The nickname of Jiří is "Jirka" in the Czech language. The specific name is a noun in apposition.
Distribution. China, Jiangxi (Fig. 54). Differential diagnosis. Trachyphloeosoma jirka sp. nov. is easily distinguishable among Chinese Trachyphloeosoma species by its long and slender protibiae, distinctly curved inwards at apical part, long piliform setae as long on pronotum as on elytra, long and slender rostrum with frons distinctly declined downwards, subdorsal eyes and long and slender plate of female sternite VIII. In comparison with non-Chinese species, T. jirka sp. nov. is, in the funicle 7-segmented, body covered by appressed setae and elytra with raised setae on all intervals similar to T. advena Zimmerman, 1956, known from Japan, Korea and introduced to U.S.A. and T. ryukyuensis Morimoto, 2015, known from Japan. It is possible to distinguish it from both by erect setae on pronotum equal in length to elytral setae (distinctly shorter in T. advena and T. ryukyuensis), elytra long, oval, 1.42-1.46 × longer than wide (oval, 1.26-1.31 × longer than wide long in T. advena and T. ryukyuensis) and protibiae slender, distinctly curved inwards at apical portion (short and robust, only slightly curved in T. advena and T. ryukyuensis) and also plate of sternite VIII in females without fenestra (with fenestra in T. advena and T. ryukyuensis). Description. Body length: 1.63-2.31 mm, holotype 1.63 mm. Body (Figs 23,24) including antennae and legs unicoloured piceous brown. Entire body except of frons, antennal funicles with clubs and tarsi covered with a brownish earth-like incrustation which conceals integument; rounded scales with hardly visible shape, but at least on pronotum, head and rostrum irregularly star-shaped. Elytra with one conspicuous dense row of erect, subspatulate setae only on odd-numbered intervals; setae almost as long as width of one interval, enlarged apicad, distance between two setae distinctly longer than length of one seta. Pronotum and head with rostrum with similar setae, approximately half length of elytral setae, densely irregularly scattered, anteriorly directed. Antennal scapes, femora and tibiae with short, erect, very slender setae, prominent from outline of scapes and legs.  Rostrum (Figs 23,24,38) 1.38-1.42 × wider than long, at base 1.23-1.28 × wider than at apex, evenly tapered anteriad with straight sides; in profile short and wide, convex. Epifrons in basal half distinctly tapered anteriad, in apical half almost parallelsided, narrow, 0.62-0.67 × as wide as rostrum in corresponding part, with ill-defined, longitudinal furrow. Frons glabrous, smooth and shiny, posteriorly continuous with epifrons. Epistome indistinct. Antennal scrobes in dorsal view visible as furrows, not reaching eyes; in lateral view distinctly subtriangular, short, strikingly enlarged posteriad with dorsal margin directed above dorsal margin of eye and ventral margin deeply below ventral margin of eye. Eyes very small, in dorsal view hardly protruding from outline of head; in lateral view placed in dorsal third, distance from dorsal margin of head distinctly longer than diameter of eye.
Penis (Fig. 43) long and slender, 2.91 × as long as wide, subparallel-sided with straight sides, slightly evenly tapered apicad; tip long, subtriangular with slightly concave sides; in lateral view slender, distinctly irregularly curved, tip pointed.
Bionomics. Type material was sifted from leaf litter in secondary forest partly with Cyathea and bamboo.
Etymology. This species is named after the curator of the National Museum in Prague and also the collector of the type specimens, Dr. Martin Fikáček. The specific name is a noun in apposition.
Distribution. China, Hainan (Fig. 54). Differential diagnosis. Trachyphloeosoma martin sp. nov. is very easily recognizable among Chinese species by the elytral raised setae only on odd-numbered intervals and also by the pronotum being somewhat longer, only slightly wider than long, not distinctly granulate on disc, almost flat. Within the genus, Trachyphloeosoma martin sp. nov. is similar only to T. roelofsi Sharp, 1896 from Japan and T. setosum (Wollaston, 1869) known from St. Helena, where it is apparently introduced (but region of origin not yet known). Trachyphloeosoma martin sp. nov. is similar to them in having raised elytral setae only on odd intervals, but distinguished from them by a more slender and longer rostrum, 1.38-1.42 × wider than long (1.56-1.73 × in T. roelofsi and T. setosum), longer and more slender elytra, 1.44-1.48 × longer than wide, (1.19-1.27 × in T. roelofsi and T. setosum), and also by the different shape of the spermatheca, with collum distinctly longer than wide (isodiametric in T. roelofsi), or long and irregularly curved cornu (short and regularly curved in T. setosum). Remarks. This species was described by Sharp from Nagasaki, Japan. Zimmerman (1956) compared the series of Trachyphloeosoma setosum Wollaston, 1869 from St. Helena with Sharp´s material of T. roelofsi from Japan and found the two series represent only one species and placed them in synonymy. However, Morimoto (2015) resurrected the name T. roelofsi as an independent species, and distinguished it from T. setosus Wollaston from St. Helena. Trachyphloeosoma roelofsi is thus known from Japan and Taiwan, while T. setosus is assumed as a species introduced to St. Helena without knowledge of its original country. Trachyphloeosoma species   1 Protibiae long and slender, 6.1-6.3 × longer than wide at midlength, at apical portion distinctly inwardly curved (Fig. 41). Elytral setae piliform, as long as setae on pronotum (Fig. 22). Rostrum long and slender, 1.12-1.18 × wider than long (Fig. 37). Frons distinctly declined from epifrons (Fig. 37). Distance between head and eye shorter than diameter of eye in profile (Fig. 37). Plate of female sternite VIII more elongate, rhombic, 2.0-2.2 × longer than wide, lacking fenestra (Fig. 49) Elytral setae on all elytral intervals, half as long as width of interval (Fig. 19). Epifrons with straight sides (Fig. 36). Dorsal margin of antennal scrobes directed towards middle of eye (Fig. 36). Pronotum shorter, 1.17-1.22 × wider than long, widest at midlength, distinctly granulate (Fig. 36). Penis short and wide, in profile wide (Fig. 42). Spermatheca with ramus and collum equally sized (Fig. 44). Female sternite VIII lacking fenestra (Fig. 48). China: Yunnan T. honza sp. nov. -Elytral setae on odd-numbered elytral intervals only, almost as long as width of interval (Fig. 23). Epifrons with concave sides (Figs 38,39). Dorsal margin of antennal scrobes directed above eye (Figs 38,39). Pronotum slightly longer, 1.07-1.15 × wider than long, widest at anterior third, almost flat (Fig. 23). Penis long and slender, slender in profile (Fig. 43). Spermatheca with collum distinctly longer than ramus (Figs 46,47). Female sternite VIII with distinct slender fenestra (Figs 50, 51)  Rostrum more slender, 1.38-1.42 × wider than long (Fig. 38). Eyes smaller, in profile with greater distance from dorsal margin of head (Fig. 38). Elytra oval, 1.44-1.48 × longer than wide. Spermatheca with ramus distinctly longer than wide (Fig. 46). Female sternite VIII with plate 1.5-1.7 × longer than wide and fenestra reaching midlength of plate (Fig. 50) (Fig. 39). Eyes larger, in profile nearer to dorsal margin of head (Fig. 39). Elytra suboval, 1.19-1.27 × longer than wide. Spermatheca with ramus isodiametric (Fig. 47). Female sternite VIII with plate twice as long as wide and fenestra reaching basal part of plate (Fig. 51)