Amamiclytus subnitidus Holzschuh, 1984

Niisato, Tatsuya & Han, Chang-do, 2011, A revision of the genus Amamiclytus Ohbayashi from Taiwan and the Ryukyu Islands (Coleoptera, Cerambycidae), ZooKeys 118, pp. 19-52 : 30-34

Amamiclytus subnitidus Holzschuh, 1984 Figs 159 –1226–333547– 52

Amamiclytus subnitidus Holzschuh, 1984: 358, fig. 6; type locality: Formosa, Takao Hsien, Laopi.

Amamiclytus hirtipes : Kojima et al. 1965: 74; Yu et al. 2001: 97, pl. 14, fig. 22; Chou 2004: 207.

Description.

Male and female. Body length (from vertex to elytral apices) 3.2-5.1 mm in ♂, 3.7-5.3 mm in ♀. Colour black, more or less glossy in general, distinctly so on elytra, dark brown on antennae, meso- and metathoraces, abdomen, brown on legs except for yellowish-brown tarsi, mouthparts, except for black mandibles, yellowish-brown. Body sparsely clothed with fine pale pubescence, with a few erect long pale hairs on genae, pronotum, pro- and mesosterna, abdominal ventrites, and along undersides of mid and hind legs except for tarsi; head sparsely clothed with pale hairs, and moderately with pale gray pubescence on frons and genae in ♂, sparsely so in ♀; antennae with long pale brown hairs along undersides of segments 2-4; pronotum thinly pubescent, sparsely with erect long pale hairs, Pb at sides transverse, slightly narrowed inwards; scutellum thinly with pale pubescence; elytra rather thinly with pale pubescence, without erect, long, pale hairs, B around scutellum rather densely pubescent, S absent, La on basal fourth semicircular, distinctly oblique, Lp on apical 2/5, almost complete, relatively narrow, slightly arcuate, A along apical margin densely pubescent; ventral surface with Ps dense near basal 2/3, Msl and Mss distinct, Mta dense along posterior margin of metasternum except near middle, distinctly dense and entire on apical 2/3 of metepisternum; V1 and V2 at sides dense, narrow to middle, V3 feebly present at sides near apical margin, though sometimes disappeared.

Head across eyes almost as wide as pronotum, HW/PW 0.91-1.13 (M 0.99) in ♂, 0.83-1.00 (M 0.91) in ♀; frons distinctly wide, about 1.7 times as wide as long, arcuately dilated apicad, with a fine shallow smooth median line, closely roughly punctured; clypeus slightly convex; vertex raised towards antennal cavities which are separated each other by 2/5 the width of occiput; occiput distinctly convex, feebly sparsely punctured. Antennae thin and long, gradually thickened apicad, attaining apical fifth in ♂ or 2/5 in ♀ of elytra; 3rd segment 1.5-2.0 times as long as 4th segment, terminal segment elongate in ♂.

Pronotum rather distinctly longer than wide, completely arcuate at sides; PL/PW, 1.05-1.33 (M 1.21) in ♂, 1.00-1.33 (M 1.15) in ♀, PB/PA 0.82-1.08 (M 0.95) in ♂, 0.92-1.00 (M 0.95) in ♀, EL/PL 2.36-3.27 (M 2.80) in ♂, 2.67-3.30 (M 2.95) in ♀, PW/EW 0.76-0.95 (M 0.84) in ♂, 0.68-0.80 (M 0.74) in ♀; disc moderately convex though slightly depressed above, provided with large shallow punctures. Scutellum regularly triangular, slightly acute at apex.

Elytra moderate in length, rather slender, EL/EW 2.58-3.13 (M 2.83) in ♂, 2.27-2.70 (M 2.51) in ♀; sides rather strongly rounded at humeri, gently arcuate at a level between basal fourth and apical half, then gently arcuate and narrowed to apices which are oblique, without any dent at inner and outer angles; disc evenly convex, sparsely provided with deep, more or less coarse punctures.

Ventral surface almost smooth, provided with a few coarse punctures on prosternum, minute ones on meso- and metathoraces and abdomen; ♂ anal ventrite 3/10 the length of basal width, truncate at apical margin.

Legs slender, relatively long; hind legs 1.5-2.0 times as long as elytra, with femur strongly swollen in apical half, and exceeding elytral apices at apical fifth, 1st tarsal segment 1.7-2.4 times as long as the following two segments combined.

Male genitalia. Median lobe about 1/3 the length of elytra moderately elongate and slender; ventral plate almost equal in width to or slightly shorter than ventral plate, gently narrowed to apex which is rounded; ventral plate almost parallel-sided near basal 2/5 then strongly narrowed to apex which is distinctly, strongly pointed at the extremity, weakly reflex in profile; median struts long and slender, almost 7/10 the length of median lobe. Endophallus densely provided with minute and medium-sized spinous spicules behind crescent-like sclerites at a level between basal 3/10 and 3/5, densely covered with minute serrate spicules on apical fourth. Tegmen slightly elongate, distinctly shorter than median lobe; parameres wide, slightly elongate, nearly half the length of tegmen, divided in apical third, gently arcuate in external margins, arcuately emarginate in inner margins, almost rounded at apices which are provided with numerous short and long setae; basal ridge moderately raised; ring part gently narrowed to apex which is widely expanded. Eighth tergite slightly elongate, almost quadrate, slightly dilated apicad in apical 2/5, apical margin weakly emarginate, provided with numerous short and a few long setae. Eighth sternite transverse, about 1/4 the length of median lobe, slightly emarginate at apical margin, strongly prominent at the middle of basal margin.

Female genitalia. Coxite lobe ovoid, scattered with four or five short setae. Stylus almost equal in length to coxite lobe, more or less elongate, gently dilated apicad. Bursa copulatrix large, distinctly constricted in basal half. Spermatheca, narrow, weakly arcuate; gland attached just behind apex; duct thin and strongly coiled throughout.

Specimens examined.

1♂ (holotype), Formosa, Takao Hsien, Laopi, 6 –IV– 1978, Kezuka leg. (Holzschuh coll.). [Taoyuan County, N. Taiwan] 2♂♂, 1♀, near Mt. Lala Shan, Fuxing Township, 12 –V– 1978, T. Shimomura leg.; 1♂, same locality, 28 –VI– 1979, J.-J. Luo leg.; 2♂♂, Sihleng, Fuxing Township, 26 –IV– 1982, N. Ohbayashi leg. [Hsinchu County, N. Taiwan] 1♂, Dalu Forest Road, Wufeng Township, alt. 1,400m, 5 –IV– 1994, C.-C. Chen leg.; 2♂♂, 2♀♀, same locality and collector, 24 –IV– 1994; 2♂♂, same locality, alt. 1,100~1,400m, 18 –V– 2002, Y.-L. Lin leg.; 2♀♀, same locality and collector, 7 –VII– 2004; 1♂, 1♀, same locality and collector, 24 –V– 2009; 1♂, 1♀, same locality, East Feeder, 27~28 –VI– 2003, D.-I. Hwang leg.; 4♂♂, 1♀, Mt. Lidong Shan, Jianshi Township, alt. 1,400m, 22 –V– 2005, Y.-L. Lin leg.; 1♀, Yufong, Jianshi Township, alt. 800m, 4 –IV– 2009, Y.-L. Lin leg. [Taichung County, C. Taiwan] 2♂♂, Deji Reservoir, Heping Township, 30 –IV– 1982, N. Ohbayashi leg.; 3♂♂, 2♀♀, Mt. Anma Shan, Heping Township, 5~28 –VI– 2002, N. Ohbayashi leg.; 1♂, 1♀, Siangyang~Liyuan, alt. 1,793~2,250m, 8 –VII– 2005, S.-T. Hisamatsu leg.; 1♀, Lilengsi Forest Road, Heping Township, alt. 1,700m, 25 –IV– 2000, W.-I Chou leg. [Nantou County, C. Taiwan] 1♀, Cueifong, Ren’ai Township, 5 –VI– 1976, T. Matsumoto leg.; 1♂, Meifong, Ren’ai Township, 7 –V– 1973, K. Matsuda leg.; 1♂, 1♀, same locality, 27 –IV– 1977, S. Saito leg.; 1♀, Songgang~Meifong, Ren’ai Township, 3 –V– 1977, J. Ito leg.; 1♂, Meiyuan, Ren’ai Township, 20 –IV– 1995, M. Hayashi leg.; 3♂♂, same locality, 28 –IV– 1995, M. Yagi leg.; 1♀, Nanshansi, Ren’ai Township, 17 –IV– 1977, W. Suzuki leg.; 1♀, same locality, 13 –IV– 1978, M. Ito leg.; 1♂, same locality, 24 –III– 1979, T. Ito leg.; 1♂, same locality and collector, 21 –IV– 1982; 1♀, same locality, 31 –III– 1980, M. Yagi leg.; 1♂, 1♀, same locality, 28~30 –III– 1981, H. Torigai leg.; 1♂, 1♀, Lianhuachih, Yuchi Township, 16 –III– 1978, J. Ito leg.; 1♀, same locality, 25 –III– 1980, K. Matsuda leg.; 13♂♂, 6♀♀, same as the preceding but 27 –III– 1980; 1♀, Sun moon Lake, Yuchi Township, 9 –IV– 1978, M. Ito leg.; 1♂, same locality, 13 –V– 1996, C.-K. Yu leg.; 1♀, same locality, alt. 800m, 3 –IV– 2000, Y.-L. Lin leg.; 2♂♂, 1♀, Bilyusi, Ren’ai Township, alt. 2,200m, 12 –V– 2002, Y.-L. Lin leg.; 1♂, same locality, 15 –V– 2007, C.-C. Chen leg.; 3♂♂, Mt. Guandao Shan, alt. 1,500m, Ren’ai Township, 12 –V– 1984, J.-J. Luo leg.; 1♀, same locality, 23 –V– 1985, M. Yagi leg.; 1♀, same locality and collector, 20 –IV– 1986; 1♀, same locality, 5 –V– 1985, K. Kusama leg.; 2♂♂, same locality, 12 –V– 2007, Y.-L. Lin leg.; 2♂♂, 1♀, Gaofeng, Ren’ai Township, 22 –III– 2007, native collector leg.; 2♂♂, 1♀, same locality, 5 –V– 2009, J.-J. Luo leg. [Hualien County, E. C. Taiwan] 1♀, Bilyu, Xiulin Township, 8 –V– 1977, S. Saito leg.; 1♂, 1♀, same locality, 2 –VI– 1978, M. Ito leg.; 2♂♂, 1♀, same locality and collector, 9 –VI– 1978; 3♂♂, same locality and collector, 13 –VI– 1978; 3♂♂, same locality and collector, 14 –VI– 1978; 9♂♂, 1♀, same locality and collector, 15 –VI– 1978; 1♂, same locality and collector, 17 –V– 1978. [Chiayi County, S. Taiwan] 1♀, Jhaoping, Alishan Township, 9 –VI– 1938, Y. Yano leg. [Kaohsiung County, S. Taiwan] 1♀, Shanping, Maolin Township, 30 –III– 1978, K. Matsuda leg.; 1♂, Mt. Nanfenshan, Liouguei Township, 22 –IV– 1985, W.-R. Chen leg.; 2♂♂, 1♀, Tengjhih, Taoyuan Township, alt. 1,400m, 28 –III– 2007, Y.-L. Lin leg. [Pingdong County, S. Taiwan] 1♂, Siaoguei Lake, Wutai Township, alt. 1,500m, 2 –V– 1998, C.-C. Chen leg.; 1♂, 1♀, Mt. Dahan Shan, Chunri Township, alt. 1,200m, 21 –IV– 2005, Y.-L. Lin leg.; 1♂, same locality and collector, 13 –IV– 2009; 1♂, 1♀, same locality and collector, 5 –V– 2009.; 1♀, same locality, 16 –IV– 2007, T. Niisato leg.; 1♂, same locality and collector, 5 –V– 2009; 7♂♂, 1♀, same locality and collector, 3 –V– 2009. 1♂, Tiantizo, 1 –VIII– 1976, K. Matsuda leg.

Geographical distribution.

Taiwan.

Comments.

Amamiclytus subnitidus Holzschuh is closely related in external morphology and pubescent maculation to Amamiclytus setiger sp. n., but is clearly separable from the latter by the sparsely pubescent pronotum, the absence of erect long pale hairs on elytra, and the transverse frons which is 1.7 times as wide as long instead of being as wide as long. These two species are also easily distinguished by the male genitalia. This species has the elongate median struts which are about 7/10 the length of the median lobe, and has a rather strongly expanded base of the ring part of the tegmen.

The population from Bilyu, Xiulin Township in east-central part of the central mountains of Taiwan, shows a slight colour variation in antennae and legs which are clearly pale brown, but other characteristics agree quite well with the populations from other localities.

This is the most common species from the genus in Taiwan, and widely recorded from various localities north to south on the island. The adult beetles appear from early spring to early summer (March to June), and visit various tree blossoms.