﻿Review of the genus Xenicotela Bates, 1884 (Cerambycidae, Lamiinae, Lamiini)

﻿Abstract The species of the genus Xenicotela Bates, 1884 are reviewed. One new species, Xenicotelamuchenisp. nov., is described from Yunnan, China. Monochamusbinigricollis Breuning, 1965 and Monochamusvilliersi Breuning, 1960 are transferred to Xenicotela as follows: Xenicotelavilliersi (Breuning, 1960) comb. nov. and Xenicotelabinigricollis (Breuning, 1965) comb. nov.Xenicoteladistincta (Gahan, 1888) is newly reported from Myanmar and Xenicotelabinigricollis is excluded from the fauna of China. All species are redescribed and illustrated. A key to the known Xenicotela species is provided.


Introduction
established the genus Xenicotela for Xenicotela fuscula Bates, 1884 [currently considered a synonym of Xenicotela pardalina (Bates, 1884)] from Higo, Japan.Recently, Xie et al. (2022) reviewed the Chinese species of the genus, increasing the number of species to five, which are known from Japan, South Korea, China, Vietnam, Laos, Nepal and India.
The present paper is a further study.The genus is reviewed, a new species is described, two Monochamus Dejean, 1821 species are transferred to Xenicotela, new photographs of the types of Monohammus distinctus Gahan, 1888 andNephelotus tonkineus Pic, 1926 are provided and a key to the known species is given.

Material and methods
Specimens from the following institutional or private collections were examined and/or photographed in this study: ZooKeys 1183: 185-204 (2023) The male genitalia of the new species were dissected and soaked in glycerine in a centrifuge tube.The genitalia were prepared by first soaking the whole beetle in boiling water for several minutes, then opening the abdomen from the apex along the dorsopleural margin.The genitalia were then removed with fine forceps and ophthalmic scissors, and later cleared in 10% KOH at 80-100 °C for several minutes.
All photographs of the habitus were taken using a Canon 7D Mark II digital camera equipped with a Canon EF 100 mm f/2.8LIS USM, while images of genitalia were taken with a Leica DFC450 digital camera mounted on a Leica M205A microscope.Images of genitalia were taken by keeping them in glycerine.All images were edited using Adobe Photoshop 2020 release.
Diagnosis.Small-bodied; body length usually less than 20 mm.Eyes coarsely faceted.Antennae long and slender, usually more than twice body length in male and about twice body length in female; antennomeres III-XI basally and apically annulated with light-coloured pubescence, basal antennomeres distinctly fringed with sparse setae ventrally; scape short, distinctly constricted before the apex, with a narrow and completely closed cicatrix at apex; antennomere III distinctly longer than fourth, about 2.0 times as long as scape.Pronotum transverse, lateral spine short, tapered.Elytra elongate, with subparallel sides, apices rounded.Procoxal cavities closed posteriorly.Mesosternal process not tuberculate, mesocoxal cavities open at sides.Legs moderately long, femora clavate, mesotibiae without grooves near external apex, claws widely divergent.
Redescription.Female.Body length 7.0-13.0mm, humeral width 2.0-3.5 mm.Body reddish brown to blackish brown, clothed with greyish-yellow pubescence forming mottling on dorsal surface.Antennae slightly lighter in colour, basal four to six segments fringed with rather sparse setae ventrally, base and extreme apex of antennomeres III-X, base and apex of antennomere XI annulated with greyish-white pubescence.Elytra clothed with rather uneven pubescence forming irregular light patches interspersed with dark patches formed by ground colour of elytra, with a vague, incomplete, dark transverse band behind middle.Underside clothed with fairly even pubescence.
Head finely punctate; frons transverse, with a smooth longitudinal median sulcus extending to occiput; eyes coarsely faceted, lower lobe longer than gena.Antennae slender, about 2.0 times as long as body, with the apex of the sixth segment surpassing elytral apex; scape robust and short, base thin, apex distinctly constricted before cicatrix; antennomere III distinctly longer than antennomere IV, about 2.5 times as long as scape; antennomeres III-X slightly thickened at extreme apex.Pronotum transverse, lateral spine small and short, coniform; surface punctured similarly to head, disc slightly uneven.Scutellum lingulate.Elytra elongate, about 2.5 times as long as width across humeri; sides slightly expanded outwards after basal third, then evenly arched and narrowed backwards; apices rounded; surface punctures coarser and sparser than those on head and pronotum, sparser and even finer towards the apex; disc slightly depressed on the basal third.Legs moderately long, femora slightly clavate, claws divaricate.
Male.Similar to female, antennae thicker and longer, about 2.5-3.0 times as long as body, with the apex of the fifth segment or the base of the sixth segment exceeding the elytral apex.
Comments.Bates (1884) described this species twice in the same publication, as M. pardalinus and X. fuscula, based on specimens from different localities.Breuning (1944) transferred M. pardalinus into the genus Xenicotela and proposed X. fuscula as its synonym.The holotype of M. pardalinus is larger in size than the holotype of X. fuscula, with longer antennae with the basal six antennomeres fringed with setae, the antennae appear darker in colour and the pubescent rings on the antennomeres look more obvious, while in the holotype of X. fuscula, only the basal four segments of the antennae are fringed with sparse setae, the fifth segment is only fringed with one or two setae and the pubescent rings on the antennomeres appear less distinct than those of the former specimen.These characters made them look like different species.Bates (1884) considered both holotypes to be males.In fact, they are females, according to the antennae / body length ratio (about 2: 1, in males 2.5-3: 1).Tavakilian and Chevillotte (2023) stated that types of both X. pardalinus and X. fuscula are conserved in the MNHN.This is not correct, as Bates described them from the collection of George Lewis (1839Lewis ( -1926)), which is in the NHMUK.Assam, India.Xenicotela distincta : Breuning 1944: 373;Gressitt 1951: 382;Breuning 1961: 354;Rondon and Breuning 1970: 458;Hubweber et al. 2010: 288;Weigel et al. 2013: 288;Kariyanna et al. 2017: 253;Lin and Tavakilian 2019: 324;Xie et al. 2022: 147. Nephelotus 4-maculatus Pic, 1925: 16.Type locality: Tonkin, Vietnam.Nephelotus tonkineus Pic, 1926: 143.Distribution.China (Yunnan, Guizhou), India (Assam, Sikkim), Vietnam (Tonkin), Nepal, Laos, Myanmar (new country record).
Redescription.Male.Body length 13.0 mm, humeral width 4.0 mm.Body mostly blackish brown, clothed with yellowish and dark-brown pubescence.Frons clothed with uniform yellowish pubescence, decorated with a black velvet patch behind each upper eye lobe.Antennae reddish brown, basal five segments fringed with sparse setae ventrally, base and extreme apex of antennomeres III-X, base and apical half of antennomere XI annulated with spare greyish-yellow pubescence.Pronotum decorated with a black velvet patch edged with greyish-yellow to yellow pubescent border on each side of basal half.Scutellum clothed with yellowish pubescence at edges.Elytra dark brown, clothed with yellowish and dark-brown pubescence forming a mixture of irregular dark and light markings.Underside mostly clothed with greyish-yellow pubescence, ventrites fringed with short yellowish setae at posterior edge and with two dark-brown spots on each side forming two incomplete longitudinal stripes.Legs mostly reddish brown; femurs and tibiae decorated with a darkbrown median annulation.
Head finely punctate, frons transverse, lower eye lobes shorter than genae.Antennae long, about 2.0 times as long as body, scape robust, distinctly constricted before cicatrix; antennomere III a little longer than antennomere IV, about 2.0 times as long as scape; antennomeres III-X slightly protruding inwards at apex.Pronotum transverse; lateral spine short and blunt, coniform; disc punctured similarly to head.Scutellum lingulate.Elytra elongate, about 2.0 times as long as width across humeri, with subparallel sides and rounded apices; surface punctures similar to those of pronotum, gradually inconspicuous towards apex.Legs moderately long, femora slightly clavate, claws divaricate. Female.Unknown.

Distribution. Vietnam (Tonkin).
Comments.This species is very similar to X. distincta, differing mainly in the elytral pattern.The irregular dark patches on the middle of each elytron are not connected into a large transverse band, while X. distincta shows a clear broad transverse middle dark band on each elytron.In addition, this species has the scutellum with the wider lighter-coloured pubescent border.The taxonomic status of this species needs to be further confirmed based on additional material.(Gressitt, 1942) Fig. 7a-f Monochamus convexicollis Gressitt, 1942: 83;Gressitt 1951: 393;Breuning 1961: 370;Chou 2004 Type material examined.Holotype, female (IZAS); label details are shown in Fig. 7f.
Type material examined.Holotype, male (MNHN), the label details are shown in Fig. 8e.Redescription.Male.Body length 13.0 mm, humeral width 4.5 mm.Body mostly dull reddish brown, clothed with greyish-yellow to pale-yellow and brown pubescence mottled on dorsal surface.Head and pronotum slightly darker than elytra; legs somewhat blackish brown.Head decorated with a dark-brown pubescent patch behind each upper lobe of eyes and a pair of homogeneous patches located at the basal half of pronotum, edged with pale-yellow pubescence and widely separated anteriorly.Antennae reddish brown; scape and pedicel densely clothed with greyish-yellow pubescence; base and extreme apex of antennomeres III-X; base and apical half of antennomere XI annulated with greyish-yellow pubescence; basal five segments fringed with sparse greyish-yellow setae ventrally.Scutellum covered with whitish yellow throughout.Elytra dull reddish brown, mottled with greyish-yellow to pale-yellow and brown pubescence.Tibiae decorated with a narrow subbasal and a wide apical annulus of greyish-yellow to pale-yellow pubescence.
Frons transverse, densely and finely punctate; lower lobes of eyes about as long as genae.Antennae long, about 2.5 times as long as body, with the apex of the fifth segment or the base of the sixth one exceeding the elytral apex; scape robust and short, base narrowed, apex distinctly constricted before cicatrix; antennomere III slightly longer than antennomere IV, about 2.5 times as long as scape; extreme apex of antennomeres III-X obviously thickened inwards.Pronotum transverse; lateral spine short and blunt, coniform; disc dotted with fine punctures.Scutellum lingulate.Elytra elongate, about 2.2 times as long as width across humeri, with subparallel sides and rounded apices; surface finely punctate, the punctures gradually becoming finer and sparser towards apex; disc slightly raised at centre of basal third, followed by a weak central depression.Legs moderately long, femora slightly clavate, claws divaricate. Female.Unknown.

Distribution. Vietnam (Tonkin).
Comments.This species has the mesotibiae without grooves near the apex, the head decorated with two black velvet patches behind the upper eye lobes, the scape distinctly constricted before the apical cicatrix, the basal five antennomeres fringed ventrally and antennomeres III-XI annulated with light-coloured pubescent rings on the base and apex, the pronotum with two black velvet patches on the base, the elytra mottled with light-coloured pubescence mixed with brown pubescence and the tibiae ringed with dark and light-coloured pubescence.All characters are consistent with the genus Xenicotela.
This species is very similar to X. bimaculata, from which it can be distinguished by the male antennae being much longer (about 2.5 times as long as body), the scutellum wholly covered with light-coloured pubescence, the base of the tibiae mostly dark with a light-coloured pubescent ring and the elytra more mottled.In X. bimaculata, the male antennae are only about 2.0 times as long as body, the scutellum is mostly clothed with light-coloured pubescence and the base of the tibiae is mostly clothed with light-coloured pubescence.Xenicotela villiersi is also similar to X. convexicollis but differs in antennomeres V-VIII more protruding inwards at the apex and the elytra less elongate, without a transverse dark band behind the middle.(Breuning, 1965), comb.nov.

Fig. 7g, h
Monochamus binigricollis Breuning, 1965: 51;Rondon and Breuning 1970: 461; Lin and Tavakilian 2019: 310.Type locality: Pak Kading, Laos.Redescription.Female.Body length 13.0 mm, humeral width 4.0 mm.Body mostly blackish brown, clothed with off-white, pale yellowish-brown to greyish-yellow and dark-brown pubescence.Head decorated with a dark-brown pubescent patch behind each upper eye lobe, a pair of homogeneous patches located at the base half of pronotum, widely separated anteriorly and indistinctly edged with pale-yellow pubescence on anterior and lateral sides.Antennae reddish brown; scape and pedicel densely clothed with greyish-yellow pubescence; base and extreme apex of antennomeres III-X; base and apical half of antennomere XI annulated with greyish-yellow pubescence; basal five segments fringed with sparse greyish-yellow setae ventrally.Scutellum completely clothed with greyish-yellow pubescence.Elytra dark brown, clothed with off-white, pale yellowish-brown to greyish-yellow and dark-brown pubescence forming a mottled pattern, distinctly dotted with irregular dark-brown spots; each elytron adorned with a large broad dark-brown median patch, slightly reduced near the suture.Tibiae decorated with a narrow subbasal and a wide apical annulus of greyish-yellow to pale-yellow pubescence.
Frons transverse, finely punctate; lower eye lobes slightly longer than genae.Antennae long, about 1.9 times as long as body; scape robust and short; base narrowed; apex distinctly constricted before cicatrix; antennomere III a little longer than antennomere IV, about 2.0 times as long as scape; antennomeres III-X slightly thickened at extreme apex.Pronotum transverse; lateral spine coniform, with pointed apex; disc dotted with fine punctures.Scutellum lingulate.Elytra elongate, about 2.3 times as long as width across humeri, with subparallel sides and rounded apices; punctures a little coarser and sparser than those on head and pronotum, sparser and even finer towards the apex; disc slightly raised at centre of basal third, followed by a weak central depression.Legs moderately long, femora slightly clavate, claws divaricate.
Comments.This species has the antennae with the scape robust and short and distinctly constricted before the cicatrix, basal five antennomeres fringed with sparse setae ventrally, and antennomeres III-XI annulated with light-coloured pubescence on base and apex; the pronotum with the lateral spine small, short and coniform, and the middle legs with the tibia without grooves.These characters are consistent with the genus Xenicotela.
This species is similar to X. distincta and X. griseomaculata, from which it differs in the lower eye lobe being longer than gena, the scutellum completely covered with light-coloured pubescence, and the base and the apex of elytra mostly clothed with light-coloured pubescence interspersed with small irregular dark-brown spots.In X. distincta, the lower eye lobe is about as long as gena, the scutellum is only clothed with the light-coloured pubescence on the edge and the elytra are not dotted with small irregular dark-brown spots.In X. griseomaculata, the lower eye lobe is shorter than gena, the scutellum is not clothed with light-coloured pubescence on the basal centre, and the base and apex of the elytra are mostly dark, adorned with light-coloured pubescent patches.Wang (1998) incorrectly identified the specimens of X. distincta from Guizhou and Yunnan as this species on the basis of the main features of two black spots behind the upper eye lobes and at the base of pronotum respectively.In fact, X. binigricollis can be easy distinguished from X. distincta, as mentioned above.Consequently, it must be excluded from the fauna of China based on the information currently available.Description.Male.Body length 16.2-19.0mm, humeral width 5.1-5.7 mm.Body mostly dark brown; antennae and legs mostly dull reddish brown, clothed with greyish-yellow, greyish-white and black pubescence forming maculations.Head densely clothed with greyish-yellow pubescence, denser and longer on labrum and clypeus, with a long oval black velvet spot behind each upper eye lobe.Antennae clothed with greyish-yellow pubescence; base and extreme apex of antennomeres III-X, basal fifth and apical two-fifths of antennomere XI annulated with sparse greyish-yellow to greyish-white pubescence.Pronotum clothed with greyish-yellow pubescence on the middle and greyish-white pubescence at sides, decorated with a short finger-like black spot on each side of basal half with apex directed obliquely outwards, base broken by a patch of greyish-yellow pubescence on the middle.Scutellum clothed with greyish-yellow pubescence, thinly edged with more light-coloured pubescence.Elytra mostly clothed with greyish-yellow pubescence, interspersed with irregular dark-brown pubescent spots throughout and white spots mainly on basal and apical fourth.Underside clothed with denser pubescence, decorated with irregular dark-brown spots on both sides; ventrites fringed with greyish-yellow pubescence on the apical margin.Legs mostly clothed with greyish-yellow pubescence; tibiae decorated with a dark pubescent ring at middle.

Xenicotela griseomaculata
Head finely and sparsely punctate; frons transverse, slightly convex, with a smooth longitudinal median sulcus extending to occiput.Eyes coarsely faceted; lower lobe about as long as gena.Antennae long, about 2.1-2.3 times as long as body; scape robust, thin at base, distinctly constricted before cicatrix; antennomere III distinctly longer than antennomere IV, about 2.7 times as long as scape; antennomere IV longer than antennomere V, antennomeres V-X strongly toothed inwards at apex.Pronotum transverse, anterior and posterior margins subequal in width; lateral spine coniform, with blunt apex; disc slightly convex, finely and sparsely punctate, with a little flat centre.Scutellum lingulate.Elytra elongate, about 2.3 times as long as width across humeri, with subparallel sides and rounded apices; surface punctures a little coarser than those on head and pronotum, gradually becoming finer and sparser towards apex, with basal fourth slightly longitudinally elevated centrally.Underside inconspicuously punctate; apical margin of distal ventrite nearly straight.Legs moderately long, femora slightly clavate, mesotibiae without grooves near external apex, claws divaricate.
Male genitalia.Tergite VIII with both sides subparallel at basal third, then converging straight to apex, apex broadly truncated, clothed with short to medium straight setae along apical and lateral sides.Tegmen about 2.37 mm long, maximum width of ringed part about 0.97 mm.Paramere about 0.39 mm long, base about 0.25 mm wide, length/width ratio about 1.56, rounded apically, clothed with setae of different lengths and thicknesses at apex.Median lobe about as long as tegmen, slightly arcuate in lateral view, apical margin of dorsal plate and ventral plate rounded; median struts relatively broad, about one-half as long as median lobe.
Female.Body length 24.1-27.1 mm, humeral width 7.3-8.5 mm.Similar to male, antennae about 1.8 times as long as body; elytra about 2.2 times as long as width across humeri; antennomeres V-X slightly thickened apically.
Distribution.China: Yunnan.Etymology.The new species is named after Mr Chen Mu, in gratitude for his offering the material of this new species for this study.
Comments.The new species differs from other species of the genus in the elytra with distinct, small, separate, irregular, white spots and the male antennae with prominent teeth on the apices of antennomeres V-IX.

Discussion
The species of the genus Xenicotela have a small body size (usually less than 20 mm in length) and are similar in appearance to the small-bodied species of the genus Monochamus and are often treated as members of the latter.The key distinguishing feature between these two genera is the presence or absence of an oblique groove near the apex of the mesotibia.In Xenicotela, the mesotibia lacks a groove near the apex.Furthermore, the scape is short, distinctly narrowed at the base, slightly swollen in the middle, clearly constricted before the apex, appearing subfusiform; the lateral spine of the pronotum is short and blunt, coniform.Antennomeres with light-coloured pubescent rings at the base and apex and fringes on the lower sides appear to be stable generic features in Xenicotela, while the presence or absence of fringes on the lower sides of the antennae cannot be used to distinguish these two genera, as several subgenera of Monochamus occurring in Africa, such as Ethiopiochamus Dillon & Dillon, 1961, Parochamus Dillon & Dillon, 1961and Quasiochamus Dillon & Dillon, 1961, are all fringed on the lower edge of the antennae (Dillon and Dillon 1961).An African species, Monochamus (Quasiochamus) nigrobasimaculatus Breuning, 1981 (Fig. 10), is very similar to members of Xenicotela in appearance, being of comparable body size, with two black velvet spots behind the upper eye lobes, the light-coloured pubescent rings at the base and apex on antennomeres III-XI, the light-coloured and dark pubescent rings on the femur, and the elytra mostly mottled, with two inconspicuous transverse dark spots after the middle.Although Breuning (1981) stated that there are no fringes on the lower sides of the antennae (non frangées en dessous), photographs of the holotype show that the antennae are distinctly fringed with the sparse pale-yellow setae below on basal five antennomeres, which also matches well with the features of Xenicotela.However, this species has large lateral pronotal spines and cylindrical scapes with unexpanded middle parts, which make it slightly different from Xenicotela.The presence or absence of a groove near the apex of the mesotibia is difficult to determine from the photographs and can only be determined after examination of the holotype.If the mesotibia has no groove, this species should be transferred into Xenicotela; conversely, if the mesotibia has a groove, its current status should be retained.As we were so far unable to directly examine the holotype, we are unable to draw a conclusion.
Monochamus is a large genus in the tribe Laminii, currently comprising 21 subgenera and over 160 species.It shows a considerable morphological variation among subgenera, which is well worth reviewing.In recent years, some species have been removed from Monochamus to other genera: M. gravidus Pascoe, 1858 to Meges Pascoe, 1866 (Bi et al. 2022), M. serratus Gahan, 1906, M. semigranulatus Pic, 1925, M. asper Breuning, 1935and M. latefasciatus Breuning, 1944to Trachystohamus Pic, 1936(Vitali and Gouverneur 2022), M. convexicollis Gressitt, 1942to Xenicotela (Xie et al. 2022), and M. fruhstorferi Breuning, 1964to Annamanum Pic, 1925[sub Annamanum lunulatum (Pic, 1934)] (Lin and Lingafelter 2018).In the present study, two additional species, M. binigricollis and M. villiersi, are transferred to Xenicotela.As the genera are studied in more depth it is likely that more species will change their current status.deposited in MNHN, to Nobuo Ohbayashi (Miura, Japan) and Junsuke Yamasako (Institute for Plant Protection, NARO, Japan) for offering the holotype photograph of M. binigricollis and the photograph of X. pardalina, to Larry Bezark (Sacramento, USA) for offering the photograph of M. binigricollis and revising the manuscription, to Meiying Lin (Mianyang Normal University, Sichuan, China) for providing the holotype photograph of M. convexicollis and revising the manuscript, to Ping Wang (Yangtze University, Jingzhou, China) for dissecting and photographing the genitalia of the new species, to Shulin Yang (Guizhou Normal University, Guiyang, China) for sharing the photograph of X. distincta, to Chen Mu (Shanghai, China) for offering the specimens of the new species for this study, and especially to Francesco Vitali (Musée national d'histoire naturelle de Luxembourg, Luxembourg), subject editor of ZooKeys, for carefully revising and patiently handling the manuscript.

Figure 2 .
Figure 2. Holotype of Xenicotela fuscula Bates, 1884, female a dorsal view b lateral view c frontal view d labels.

Figure 3 .
Figure 3. Xenicotela distincta (Gahan, 1888), specimen from Myanmar a dorsal view b ventral view c lateral view d frontal view e labels.

Figure 4 .
Figure 4. Holotype of Monohammus distinctus Gahan, 1888 a dorsal view b ventral view c lateral view d frontal view e labels.

Figure 5 .
Figure 5. Syntypes of Nephelotus tonkineus Pic, 1926 a-e male f-j female.a, f dorsal view b, g ventral view c, h lateral view d, i frontal view e, j labels.

Figure 6 .
Figure 6.Holotype of Nephelotus bimaculatus Pic, 1925 a dorsal view b ventral view c lateral view d frontal view e labels.

Figure 9 .
Figure 9. Xenicotela spp.a, b, g holotype of Xenicotela griseomaculata, male c-f, h-o Xenicotela mucheni sp.nov.c, d, h male e, f female a, c, e, i, k dorsal view b, d, f, j, m, n ventral view l, o lateral view g, h frontal view i-o male genitalia i, j tergite VIII k-l tegmen + median struts n, o spiculum gastrale.Scale: 0.5 mm.