Amamiclytus nubilus, Niisato, Tatsuya & Han, Chang-do, 2011

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 : 36-39

Amamiclytus nubilus sp. n. Figs 15 –163759– 64

Description.

Male and female. Body length (from vertex to elytral apices) 3.6-4.5 mm in ♂, 4.0-5.2 mm in ♀. Colour almost as in Amamiclytus subnitidus , though distinctly matted in general. Body densely clothed with fine pale pubescence, partly with erect, long, pale hairs especially dense on mid and hind tibiae; head moderately with pale hairs, rather densely with pale gray pubescence on frons in ♂, sparsely in ♀; antennae moderately with pale pubescence, with long pale brown hairs on undersides of segments 2-5; pronotum rather densely with pale pubescence, with erect, long, pale hairs, Pb conspicuous; scutellum rather thinly with pale pubescence; elytra densely with light brown pubescence throughout, without erect, long, pale hairs, B absent, S on basal tenth dense and elongate, La on basal third strongly arcuate, slightly oblique, Lp on apical 2/5 almost complete, narrow, distinctly oblique, A distinct though rather narrow; prosternum densely with white pubescence near basal 2/3, Msl and Mss distinct, Mta dense and enlarged on entire of metepisternum; V1-V4 dense, narrow to middle, though V3-V4 sometimes sparse; fore and mid legs with pale gray pubescence, especially dense on femora.

Head almost as wide as pronotum, HW/PW 0.89-1.00 (M 0.99) in ♂, 0.89-1.00 (M 0.95) in ♀; frons as long as wide, arcuately dilated apicad, with a thin weak smooth median line, finely sparsely punctured; clypeus slightly convex; vertex raised towards antennal cavities which are separated from each other by half the width of occiput; occiput distinctly convex, sparsely punctured. Antennae thin and long, gradually dilated apicad, attaining apical half in ♂ or 3/5 in ♀ of elytra; 3rd segment 1.3-2.0 times as long as 4th segment, terminal segment short, rounded at apex in ♂.

Pronotum slightly or moderately longer than wide, weakly arcuate at sides; PL/PW, 1.13-1.38 (M 1.25) in ♂, 1.10-1.29 (M 1.19) in ♀, PB/PA 1.00-1.00 (M 1.00) in ♂, 1.00-1.06 (M 1.01) in ♀, EL/PL 2.45-3.22 (M 2.80) in ♂, 2.69-3.00 (M 2.86) in ♀, PW/EW 0.75-0.90 (M 0.84) in ♂, 0.75-0.83 (M 0.79) in ♀; disc moderately convex, provided with large shallow punctures. Scutellum regular triangular, acute at apex.

Elytra relatively long and slender; EL/EW 2.70-3.18 (M 2.94) in ♂, 2.50-2.83 (M 2.68) in ♀; sides distinctly rounded at humeri, gently arcuate at a level between basal fifth and apical half, then gently arcuate and narrowed to apices which are oblique, slightly arcuate at margins, minutely acute at outer angles; disc evenly convex, densely provided with fine shallow punctures.

Ventral surface almost smooth, provided with a few coarse punctures on prosternum, with minute punctures on meso- and metathoraces, and abdomen; anal ventrite in ♂, 3/5 the length of basal width, moderately arcuate at apical margin.

Legs slender, relatively long; hind legs 1.5-1.8 times length of elytra, with femur weakly swollen in apical half, exceeding elytral apices at apical fifth, 1st tarsal segment 1.5-2.0 times as long as the following two segments combined.

Male genitalia. Median lobe nearly 2/5 the length of elytra, wide, moderately elongate; ventral plate almost equal in width to, or a little shorter than ventral plate, gently narrowed to apex which is bluntly rounded; ventral plate almost parallel–sided near basal half then more or less strongly narrowed to apex which is distinctly pointed at the extremity, weakly reflexed in profile; median struts elongate, almost half the length of median lobe. Endophallus densely provided with minute spinous spicules behind crescent-like sclerites from basal 1/5 to 3/5, densely covered with minute serrate sclerites on apical third. Tegmen more or less elongate, distinctly shorter than median lobe; parameres elongate, slightly slender, nearly 2/5 the length of tegmen, divided in apical third, with lobe gently arcuate in external margin, arcuately emarginate in inner margin, almost rounded at apices which are provided with numerous short and a few long setae; basal ridge moderately raised, gently convergent to apex. Eighth tergite slightly elongate, semicircular, gently convergent to apex in apical half, with apical margin weakly arcuate, provided with numerous short setae. Eighth sternite more or less small, distinctly transverse, gently emarginate at apical margin.

Female genitalia. Coxite lobe ovoid, sparsely provided with short and long setae. Stylus almost half oflength ofcoxite lobe, elongate, gently dilated apicad. Bursa copulatrix small, strongly constricted in basal 2/3. Spermatheca slightly narrow, strongly arcuate; gland thin, attached at apical 2/5; duct more or less thin, slightly sinuate, not coiled.

Type series.

Holotype ♂, Sinsian, Wulai Township, Taipei County, alt. 300m, N. Taiwan, 4 –III– 2000, Y.-L. Lin leg. Allotype ♀, Lianhuachih, Yuchi Township, Nantou County, C. Taiwan, 20 –III– 1978, J. Ito leg. Paratypes (54♂♂, 23♀♀): [Taipei County, N. Taiwan] 1♂, Wulai, 21 –II– 2004, Y.-L. Lin leg.; 1♀, Sinsian, Wulai Township, alt. 300m, 11 –III– 2000, Y.-L. Lin leg.; 1♂, Fushan, Wulai Township, 21 –III– 1998, M. Sakai leg. [Taoyuan County, N. Taiwan] 3♂♂, Sule, Fuxing Township, 26 –III– 1979, T. Ito leg.; 1♂, same locality and collector, 28 –III– 1979; 6♂♂, 1♀, Sihleng, Fuxing Township, 26 –IV– 1982, N. Ohbayashi leg.; 1♂, same locality and collector, 28 –IV– 1982; 1♀, Baling, Fuxing Township, 31 –III– 1998, M. Sakai leg.; 1♀, Ronghua, Fuxing Township, 15 –III– 1998, C.-C. Chen leg.; 3♂♂, same locality, alt. 500m, 3 –III– 2002, Y.-L. Lin leg.; 6♂♂, Ronghua, Fuxing Township, alt. 500m, 27 –III– 2003, Y.-L. Lin leg.; 3♂♂, 1♀, Gaoyi, Fuxing Township, alt. 500m, 21 –IV– 2007, Y.-L. Lin leg. [Hsinchu County, N. Taiwan] 1♀, Dalu Forest Road, Wufeng Township, 17 –IV– 1994, C.-C. Chen leg.; 1♂, 1♀, same locality, alt. 1,100~1,400m, 24 –III– 2007, Y.-L. Lin leg.; 1♂, same locality and collector, 15 –III– 2009; 1♀, same locality and collector, 1 –IV– 2009.; 1♂, 1♀, Shihlei, Jianshi Township, 6 –III– 2010, Y.-L. Lin leg. [Nantou County, C. Taiwan] 10♂♂, 2♀♀, Lianhuachih, Yuchi Town ship, 16 –III– 1978, J. Ito leg.; 5♂♂, 1♀, same locality and collector, 17 –III– 1978; 1♂, same locality and collector, 18 –III– 1978; 1♀, Gaofeng, Ren’ai Township, alt. 1,300m, 5 –V– 2009, J.-J. Luo leg.; 1♀, Nanshansi, Ren’ai Township, 30 –III– 1972, K. Matsuda leg.; 1♂, same locality, 19 –III– 1978, J. Ito leg.; 1♂, same locality and collector, 22 –III– 1978; 1♀, same locality and collector, 26 –III– 1978; 1♂, 1♀, same locality, 11 –IV– 1978, M. Ito leg.; 1♂, 1♀, same locality and collector, 14 –IV– 1978; 1♂, same locality and collector, 29 –IV– 1978; 1♂, 1♀, same locality, 19 –III– 1978, C.-K. Yu leg.; 1♂, same locality, 17 –III– 1979, T. Ito leg.; 2♀♀, same locality and collector, 24 –III– 1979; 1♀, same locality, 28 –III– 1980, M. Yagi leg.; 1♀, same locality, 3 –IV– 1981, Y. Yamamoto leg. [Hualien County, E. C. Taiwan] 1♂, Bilyu, Xiulin Township, 2 –VI– 1978, M. Ito leg. [Kaohsiung County, S. Taiwan] 1♂, 8 –III– 1978, J. Ito leg.; 1♀, same collector, Wetuan, Liugui Township, 7 –III– 1978. [Pingdong County, S. Taiwan] 1♂, Mt. Dahan Shan, Chunri Township, 1 –III– 2007, T. Yoro leg. Holotype and allotype are preserved in NMNS, and paratypes are in EUMJ, HUM, MMNS, NHMO and the private collections of the above collectors.

Geographical distribution.

Taiwan.

Comments.

In having the matted body with similar pattern of white pubescent maculation on the elytra, Amamiclytus nubilus sp. n. is somewhat similar to Amamiclytus juni and Amamiclytus yulongi spp. n. which will be subsequently described, but is clearly distinguished from these two congeners by the relatively elongate pronotum with white pubescent maculation along the basal margin. Considering the male genitalia, this new species has some relationship with Amamiclytus subnitidus Holzschuh and Amamiclytus setiger sp. n., but is clearly separable from them by markedly broadened median lobe and rather narrow ring parts of tegmen. Besides, it is very unique that this new species and Amamiclytus hirtipes (Matsushita), comb. n. share an uncoiled duct in spermatheca of female genitalia in spite of strongly coiled ones in the other five species from Japan and Taiwan. The true affinity of Amamiclytus nubilus is uncertain since the morphological convergence is recognized in both external and genitalic features between some sympatric species of the genus. It may be possible to consider that Amamiclytus nubilus sp. n. has the closest relationship with Amamiclytus hirtipes (Matsushita), comb. n. by their uncoiled duct of spermatheca.

Amamiclytus nubilus sp. n. is widespread over the entire island of Taiwan and is rather common among the Taiwanese members of the genus. Adult beetles are usually found on various kinds of tree blossoms in the spring season mainly from March to April.