Research Article |
Corresponding author: Maxwell V. L. Barclay ( m.barclay@nhm.ac.uk ) Corresponding author: Wenkai Wang ( wwk@yangtzeu.edu.cn ) Academic editor: Francesco Vitali
© 2023 Guanglin Xie, Maxwell V. L. Barclay, Wenkai Wang.
This is an open access article distributed under the terms of the Creative Commons Attribution License (CC BY 4.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original author and source are credited.
Citation:
Xie G, Barclay MVL, Wang W (2023) Review of the genus Xenicotela Bates, 1884 (Cerambycidae, Lamiinae, Lamiini). ZooKeys 1183: 185-204. https://doi.org/10.3897/zookeys.1183.112490
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The species of the genus Xenicotela Bates, 1884 are reviewed. One new species, Xenicotela mucheni sp. nov., is described from Yunnan, China. Monochamus binigricollis Breuning, 1965 and Monochamus villiersi Breuning, 1960 are transferred to Xenicotela as follows: Xenicotela villiersi (Breuning, 1960) comb. nov. and Xenicotela binigricollis (Breuning, 1965) comb. nov. Xenicotela distincta (Gahan, 1888) is newly reported from Myanmar and Xenicotela binigricollis is excluded from the fauna of China. All species are redescribed and illustrated. A key to the known Xenicotela species is provided.
Coleoptera, Cerambycidae, identification key, new species, new combination, taxonomy
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 and Nephelotus tonkineus Pic, 1926 are provided and a key to the known species is given.
Specimens from the following institutional or private collections were examined and/or photographed in this study:
LGBC Collection of Larry G. Bezark, Sacramento, California, USA;
MCC Collection of Mu Chen, Shanghai, China;
NOC Collection of Nobuo Ohbayashi, Miura, Japan;
SWU Southwest University, Chongqing, China;
YZU Yangtze University, Jingzhou, China.
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/2.8L IS 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.
Xenicotela
Bates, 1884: 242;
Xenicotela fuscula Bates, 1884 [= Xenicotela pardalis (Bates, 1884)].
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.
Japan, South Korea, China, Vietnam, Laos, Myanmar (new country record), Nepal, India.
The genus was often confused with Monochamus (
Monochamus pardalinus
Bates, 1884: 239;
Xenicotela pardalina:
Xenicotela fuscula
Bates, 1884: 242;
Holotype
of Monohammus pardalinus, female (
One male, Japan: Honshu, Tottori Pref., Mt. Daisen, July 22–23, 1974, coll. Y. Notsu (NOC); One female, Japan: Shikoku, Tokushima Oref., Dosu-toge, July 29, 1973, coll. M. Sakai (NOC).
Female. Body length 7.0–13.0 mm, 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.
Japan (Hokkaido, Honshu, Sado, Oki, Shikoku, Kyushu, Tanegashima, Yakushima), South Korea (Seoraksan).
Monohammus distinctus
Gahan, 1888: 392;
Xenicotela distincta:
Nephelotus 4-maculatus Pic, 1925: 16. Type locality: Tonkin, Vietnam.
Nephelotus tonkineus Pic, 1926: 143. Type locality: Tonkin (Hoa Binh), Vietnam.
Xenicotela distincta m. tonkinensis Breuning, 1944: 373.
Monochamus binigricollis:
Holotype
of Monohammus distinctus, male (
One female, ‘Burmah’ (
China (Yunnan, Guizhou), India (Assam, Sikkim), Vietnam (Tonkin), Nepal, Laos, Myanmar (new country record).
One female specimen of this species labelled ‘Burmah’ (old spelling of Burma, i.e., Myanmar) was found in
Nephelotus bimaculatus Pic, 1925: 16. Type locality: Tonkin (Hoa Binh), Vietnam.
Xenicotela bimaculatus:
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 dark-brown 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.
Vietnam (Tonkin).
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.
Monochamus convexicollis
Gressitt, 1942: 83;
Xenicotela convexicollis:
Holotype
, female (
Xenicotela spp. a–f Xenicotela convexicollis (Gressitt, 1942) g–h Xenicotela binigricollis (Breuning, 1965) comb. nov. a, c male, from Zhejiang (Tianmushan), China b, d female, from Zhejiang (Tianmushan), China e, f holotype (female) and labels g female, from Bac Kạn (Ba Be national park), Vietnam h holotype, female.
One male and one female: China, Zhejiang, Lin’an, West Tianmushan, July 13, 2012, collected by Guanglin Xie (YZU); one female: China, Zhejiang, Lin’an, Qingliangfeng, May 22, 2012, collected by Guanglin Xie (YZU).
China (Zhejiang, Taiwan).
The redescription and comments about this species refer to
Monochamus villiersi
Breuning, 1960: 33;
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.
Vietnam (Tonkin).
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.
Monochamus binigricollis
Breuning, 1965: 51;
Holotype
, female (
One female, Vietnam: Bac Kạn Province, National Park (LGBC).
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.
Male. Unknown.
Laos (Pak Kading), Vietnam (Tonkin).
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.
Xenicotela griseomaculata
Holotype , male, China: Chongqing, Wuxi County, Xiabao township, Shuanghe Village, 31°21'4"N, 109°11'24"E, July 26, 2019, coll. Bin Chen.
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.
China (Chongqing).
Description and comments on this species are provided by
Holotype : male, China: Yunnan Province, Ruili (瑞丽), July 29, 2018, coll. local collector, deposited in the Insect Collection, College of Agriculture, Yangtze University (YZU). Paratypes: one male and two females, China: Yunnan Province, Yingjiang County (盈江), Xima (昔马), Alt. 600–1200 m, July 29 to August 10, 2018, coll. by local collector, deposited in the Collection of Mu Chen (MCC, Shanghai, China).
Male. Body length 16.2–19.0 mm, 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.
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.
China: Yunnan.
The new species is named after Mr Chen Mu, in gratitude for his offering the material of this new species for this study.
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.
1 | Elytra mostly clothed with greyish-yellow pubescence, without whitish pubescent patches | 2 |
– | Elytra decorated with distinct greyish white or white pubescent spots or, at least, with light-coloured pubescent maculations of off-white pubescence mixed with greyish-yellow pubescence | 6 |
2 | Pronotum with two distinct dark-brown spots | 3 |
– | Pronotum without such spots; elytral pubescence thin; each elytron with an incomplete transverse dark-brown patch after middle | Xenicotela pardalina (Bates, 1884) |
3 | Scutellum wholly covered with light-coloured pubescence | 4 |
– | Scutellum only clothed with light-coloured pubescence on edge, with dark-brown pubescence on central part | 5 |
4 | Light-coloured pubescent ring at base of antennomere III relatively long, about one-fourth as long as antennomere III; dark-brown spots on pronotal base distinctly edged with pale-yellow pubescence; each elytron without distinct transverse dark patches | Xenicotela villiersi (Breuning, 1960), comb. nov. |
– | Light-coloured pubescent ring on base of antennomere III shorter than one-fourth of length of antennomere III; dark-brown spots on pronotal base without conspicuous pubescent border; each elytron with a distinct but incomplete transverse dark patch | Xenicotela convexicollis (Gressitt, 1942) |
5 | Each elytron with a distinct large transverse dark-brown patch on the middle | Xenicotela distincta (Gahan, 1888) |
– | Each elytron with irregular dark-brown patches that do not fuse into a distinct large transverse dark-brown patch on middle | Xenicotela bimaculata (Pic, 1925) |
6 | Apex of male antennomeres V–IX only weakly protruding inwards; elytra with relatively large light-coloured pubescent patches | 7 |
– | Apex of male antennomeres V–IX strongly toothed inwards; elytra with scattered irregular small white pubescent spots | Xenicotela mucheni sp. nov. |
7 | Apical fourth of elytra mostly clothed with light-coloured pubescence, with irregular dark spots | Xenicotela binigricollis (Breuning, 1965), comb. nov. |
– | Apical fourth of elytra mostly dark, with greyish-white pubescent patches | Xenicotela griseomaculata Xie, Barclay & Chen, 2022 |
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, 1961 and Quasiochamus Dillon & Dillon, 1961, are all fringed on the lower edge of the antennae (
An African species, Monochamus (Quasiochamus) nigrobasimaculatus Breuning, 1981 (Fig.
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 (
We wish to express our sincere thanks to Antoine Mantilleri (Muséum national d’Histoire naturelle, Paris) for taking the photographs of type specimens deposited in
The authors have declared that no competing interests exist.
No ethical statement was reported.
This research was supported by the China Scholarship Council (202008420315) and the National Natural Science Foundation of China (31672327).
Funding acquisition: WW. Writing – original draft: GX. Writing – review and editing: MVLB.
Guanglin Xie https://orcid.org/0000-0003-3273-8985
Maxwell V. L. Barclay https://orcid.org/0000-0003-4989-2014
Wenkai Wang https://orcid.org/0000-0002-4482-076X
All of the data that support the findings of this study are available in the main text.