A revision of the genus Amamiclytus Ohbayashi from Taiwan and the Ryukyu Islands (Coleoptera, Cerambycidae)

Abstract The clytine genus Amamiclytus Ohbayashi, 1964, from Taiwan and the Ryukyu Islands is revised. Seven species and one subspecies are recognized as follows: Amamiclytus nobuoi nobuoi Ohbayashi, 1964, (Amami Islands); Amamiclytus nobuoi akusekianus Niisato, 2005, (Tokara Islands); Amamiclytus subnitidus Holzschuh, 1984, (Taiwan); Amamiclytus setiger sp. n. (Taiwan), Amamiclytus nubilus sp. n. (Taiwan), Amamiclytus juni sp. n. (Taiwan), Amamiclytus yulongi sp. n. (Taiwan) and Amamiclytus hirtipes (Matsushita, 1940), comb. n. (Taiwan). All of them are described or redescribed and a key to species is presented. The generic features of Amamiclytus, including male and female genitalia from these taxa, are presented. The systematic position of Amamiclytus within the tribe Clytini is discussed.


Introduction
Clytine beetles of the genus Amamiclytus Ohbayashi, 1964, are easily recognized at first observation by the small, black and glossy body with the ordinary arrangement of white pubescent maculation on the elytra. The genus is distinguishable from related genera, like Rhaphuma Pascoe, by rather widely separated antennal insertions, long, erect, pale hairs on the middle and hind tibiae, and also by the peculiar structure of the male endophallus. Up to the present time, a total of seven taxa, including one subspecies, have been recorded from a rather restricted area between the Ryukyu Islands of Southwest Japan and northern Indochina. They are Amamiclytus nobuoi nobuoi Ohbayashi, 1964, from Amami Isls., Japan, A. nobuoi akusekianus Niisato, 2005, from Tokara Isls., Japan, A. hirtipes (Matsushita, 1940), from Taiwan, A. subnitidus Holzschuh, 1985, from Taiwan, A. dembickyi Holzschuh, 1991, from North Vietnam, A. squamifer Holzschuh, 1991, and A. setosulus Holzschuh, 1991 In spite of Taiwan's rich longicorn beetles fauna, only two species of this genus, A. hirtipes and A. subnitidus, were known from there. The first author preliminarily examined the Taiwanese Amamiclytus species more than a quarter century ago, and presented an oral report at the annual meeting of the Japanese Society of Coleopterology (Niisato 1983). According to his provisional report, a total of six species in the genus were recognized from Taiwan, of which five were unnamed species.
In this study, we basically follow the work of Niisato (1983), and carefully describe or redescribe the members of the genus from Taiwan and the Ryukyu Islands considering details of external morphology and male and female genitalia. We also discuss the systematic position of Amamiclytus in the tribe Clytini.

Abbreviations
Measurements of body parts. HW-width of head across eyes; PL-length of pronotum; PW-maximum width of pronotum; PA-apical width of pronotum; PB-basal width of pronotum; EL-length of elytra; EW-humeral width of elytra; M-arithmetic mean.
Maculations consisting of white pubescence. Dorsal side: Pb-basal band on pronotum, usually enlarged along entire margin; B-basal bands near elytral bases; S-sutural spot on elytra behind scutellum; La-lateral bands before middle of elytra, sometimes almost reaching or joining S; Lp-transverse bands behind middle of elytra, usually incomplete, not reaching external and sutural margins; A-apical bands of elytra. Ventral side: Msl-lateral maculation of mesosternum; Mss-maculation on mesosternal process; Mta-L-shaped band along apical margin of metathorax, extending to apical 1/2-2/3 of metepisternum; V1-V4-lateral bands along apical margins of ventrites 1-4, usually enlarged along entire apical margin in basal segments.

historical review
The genus Amamiclytus Ohbayashi, 1964, was established for A. nobuoi Ohbayashi from Amami-Ôshima Is., Southwest Japan. Later, this type species was synonymized with the Taiwanese species, Rhaphuma hirtipes Matsushita, 1940, by Kojima et al. (1965. They also re-affirmed the validity of the genus Amamiclytus and placed it under Amamiclytus as A. hirtipes (Matsushita, 1940). According to their paper, this action was made by comparison with specimens determined as R. hirtipes by the late Dr. M. Hayashi from his collection. Later, Kusama and Takakuwa (1984) restored A. nobuoi as a valid species. However, they never examined the true R. hirtipes, and confused several different species in the genus with it. So at least as of that time, it was uncertain whether R. hirtipes should be transferred to the genus Amamiclytus or not.
The holotype of Rhaphuma hirtipes was assumed to be deposited in an institution somewhere in Berlin, or lost during the war. However, the first author discovered the holotype of R. hirtipes in the general collection of the Hokkaido University. By examination of this type specimen, Niisato (1983) accepted the placement in the genus Amamiclytus, and recognized six species in the genus, of which five needed to be described as new taxa for the Taiwanese fauna. After Niisato's presentation, A. subnitidus Holzschuh, 1984, was described from Kaohsiung, Taiwan. Until now, four taxa in this genus from Taiwan have remained undescribed.
Based on our recent examination of the late Dr. Masao Hayashi's collection deposited in the Natural History Museum of Osaka, we only located a single species, A. subnitidus, in his collection. This indicates that the previously incorrect action by Kojima et al. (1965) was due to the misidentification of A. subnitidus with A. hirtipes. Succeeding authors of the picture books of Taiwanese Cerambycidae (Yu and Nara 1988, Yu et al. 2002, Hua et al. 2009) inherited this mistake. Pronotum globose or slightly elongate, slightly narrower than elytra, simply arcuate at sides; disc distinctly convex though slightly depressed above, provided with large shallow punctures. Scutellum small, regular triangular.
Elytra relatively short to relatively long; sides rounded at humeri, weakly arcuately emarginate at a level between basal fourth and apical half; apices oblique, slightly arcuate at margins, usually with weak dents at external angles; disc evenly convex with slight depression near suture just behind scutellum. Hind wing with vein Cu not attaining AA 3+4 which is forming an ordinary H-shape.
Ventral surface smooth; prosternum moderately emarginate near apical half in profile; metasternum slightly convex; abdomen relatively slender, with male anal ventrite arcuately rounded at apical margin.
Legs long and slender; hind legs 1.5-2.0 times as long as elytra, with femur gradually swollen apicad, slightly compressed, usually exceeding elytral apex at apical fifth, almost equal to the length of hind tibia, 1st tarsal segment varied in length according to species, 1.5-2.5 times as long as the following two segments combined.
Male genitalia. Relatively large and somewhat elongate, basically related to that of several species of Rhaphuma. Median lobe elongate and slender, slightly reflexed in profile; dorsal plate almost equal in width to, or a little longer than ventral plate, gently narrowed to rounded apex; ventral plate gently narrowed to pointed apex; median struts slender. Endophallus about twice the length of median lobe, provided with minute or medium-sized spinous spicules behind crescent-like sclerites, densely cov- ered with minute serrate or crenulate spicules on apical part. Tegmen usually elongate, shorter than median lobe; parameres nearly half to 2/5 the length of tegmen, divided in apical fifth to third, with each lobe almost rounded at apex, which is provided with short and long setae; basal ridge raised. Eighth tergite more or less elongate, slightly longer than wide. Eighth sternite distinctly transverse, emarginate or transversely truncate at apical margin, provided with long projection at middle of basal margin.
Female genitalia. Coxite lobe ovoid, scattered with short and long setae. Stylus half to equal in length to coxite lobe, elongate, weakly dilated apicad. Spermatheca narrow, weakly broadened apicad; gland short and thin; duct relatively long and thin.
Geographical distribution. Indochina, China, Taiwan, Japan (Ryukyus), Malay Peninsula, Sumatra and Borneo.  Comments. The species of the genus Amamiclytus Ohbayashi have so far been known from a rather restricted area between Indochina and the Ryukyu Islands of Southwest Japan. However, several undetermined species belonging to the genus have been found from Sumatra, Borneo and the Malay Peninsula. The genus contains small, glossy black species with pure white pubescent maculations on the body surface, and are slightly similar in external appearance to several members of the genus Rhaphuma Pascoe. They share the following features: 1) body relatively elongate, especially in elytra, meso-and metasterna, and legs; 2) antennae thin and long, with 3rd segment usually longer than scape; 3) antennal cavities approximate each other; 3) eyes large and prominent, rather distinctly approximate in front; 4) mandible almost smooth and provided with numerous short hairs along inner margin; 5) labial and  (Matsushita), comb. n., ♂ 23 ditto, ♀. maxillary palpi show distinct sexual dimorphism in each terminal segment, strongly dilated apicad in ♂ or weakly so in ♀. However, Amamiclytus is very distinct in the tribe Clytini by a combination of the following characters: 1) body small and rather convex, with relatively long antennae and legs; 2) colour wholly black, usually brownish antennae and legs, strongly glossy or sometimes more or less matted; 3) white scaly pubescence form the maculations on elytra, ventral surface and sometimes on the base of pronotum, of which elytra are always provided with three arcuate or transverse bands, sometimes supplemented with vague basal band along basal margin and a longitudinal spot near suture behind scutellum; 4) mid and hind tibiae provided with long erect hairs; 5) frons relatively wide, with a fine median groove; antennae usually thickened towards apical segments, though simply slender in A. hirtipes, with antennal cavities widely separated at sides of frons; 6) pronotum rather convex, simply arcuate at sides; 7) male genitalia relatively large, with endophallus densely provided with minute serrate or crenulate spicules on apical part, without spinous spicules.
Adults of the genus are usually found on various types of tree blossoms as Castanopsis, Quercus and Acer mainly in spring and early summer season, such as February to June, except for A. hirtipes which appears in the autumn season. Larvae of A. nobuoi, bore in the dead, thin twigs of Machilus thunbergii and Rhaphiolepis indica var. umbellata (Niisato, 2007).  Kojima et al. 1965: 85. (nec Matsushita, 1940 Amamiclytus nobuoi nobuoi : Niisato 2007: 502. Description. Male and female. Body length (from vertex to elytral apices) 4.0-5.1 mm in ♂, 4.0-4.9 mm in ♀. Colour black, glossy in general, distinctly so on elytra, dark brown in antennae, meso-and metathoraces, abdomen and legs except for pale brown tibiae and yellowish brown tarsi, mouthparts except for black mandibles yellowish brown. Body moderately clothed with fine pale pubescence, sparsely with erect long pale hairs on clypeus, genae, near pronotal base, abdominal ventrites and hind tibiae; head sparsely with pale hairs, largely exposing disc, scattered with a few erect long pale hairs, very thinly with pale gray pubescence on frons in both sexes; antennae distinctly with long pale brown hairs along undersides of segments 2-5; pronotum largely exposing disc, thinly pubescent, with a few erect long pale hairs, Pb at sides transverse, slightly narrowed inwards; scutellum hardly pubescent; elytra sparsely with pale pubescence, without long erect pale hairs, B very sparse, barely recognized, S on basal eighth small and longitudinally oblong, La on basal third semicircular, slightly oblique, Lp on apical third, almost complete though narrow, weakly arcuate, A moderately dense; prosternum moderately with white pubescence near basal 2/3, Msl distinct, Mss almost absent, Mta very sparse along posterior margin of metasternum, dense and entire on apical 2/5 of metepisternum; V1 and V2 dense, narrowed to middle.

Key to species of the genus Amamiclytus from Taiwan and the Ryukyu Islands
Head across eyes almost as wide as pronotum, HW/PW 0.80-1.06 (M 0.95) in ♂, 0.89-0.95 (M 0.92) in ♀; frons as long as wide, arcuately dilated apicad, with a fine but deep smooth median line, closely roughly punctured; clypeus almost flattened; vertex raised towards antennal cavities which are separated from each other by about half the width of occiput; occiput distinctly convex, sparsely punctured. Antennae thin and long, gradually thickened apicad, attaining apical third in ♂ or 3/5 in ♀ of elytra; scape almost cylindrical, 3rd segment 1.4-1.8 times as long as 4th segment, middle segments weakly thickened at apices, terminal segment short, rounded at apex in ♂.
Pronotum slightly longer than wide, strongly arcuate at sides; PL/PW, 1.18-1. in ♀; disc moderately convex though slightly depressed above, provided with large shallow punctures, though densely finely punctured in apical half in ♂. Scutellum regular triangular, slightly acute at apex.
Elytra relatively long and slender, EL/EW 2.73-2.86 (M 2.78) in ♂, 2.55-2.80 (M 2.64) in ♀; sides with almost rounded humeri, gently arcuate at a level between basal fourth and apical half, then gently arcuate and narrowed to oblique apices, without any dent at inner and outer angles; disc almost evenly convex, sparsely provided with fine shallow punctures.
Ventral surface almost smooth, provided with a few coarse punctures on prosternum, minute ones on meso-and metathoraces and abdomen; ♂ anal ventrite 3/5 the length of basal width, weakly arcuate at apical margin.
Legs slender, rather long; hind legs 1.4-1.7 times as long as elytra, with femur strongly swollen in apical half, slightly exceeding elytral apex, 1st tarsal segment 1.6-2.0 times as long as the following two segments combined.    (Matsushita). ct coxite lobe st stylus b bursa copulatrix sp spermatheca d spermathecal duct g spermathecal gland. Scale: 0.5 mm.
Male genitalia. Median lobe about 2/5 the length of elytra, slender and elongate; dorsal plate slightly wider than ventral plate in apical eighth, distinctly narrowed to apex which is rounded; ventral plate almost parallel-sided in basal half, then strongly narrowed to apex which is strongly pointed at the extremity, slightly reflex in profile; median struts slender, almost half the length of median lobe. Endophallus densely provided with minute spinous spicules behind crescent-like sclerites at a level between basal 2/5 and 4/5, densely covered with minute serrate spicules on apical sixth. Tegmen elongate, slightly shorter than median lobe; parameres more or less elongate, nearly 2/5 the length of tegmen, divided in apical fourth, gently arcuate in external margins, arcuately emarginate in inner margins, almost rounded at apices which are provided with numerous short and a few long setae; basal ridge slightly raised; ring part almost parallel-sided in basal third. Eighth tergite slightly elongate, semicircular, gently narrowed apicad in apical fourth, with apical margin weakly arcuate, provided with numerous short and a few long setae. Eighth sternite very small, distinctly transverse, almost 1/3 the length of median lobe, with apical margin almost transverse, deeply concave at middle.
Female genitalia. Coxite lobe ovoid, scattered with short and long setae. Stylus almost half in length to coxite lobe, elongate, weakly dilated apicad. Bursa copulatrix small, weakly constricted near base. Spermatheca narrow, gently arcuate, weakly broadened apicad; gland thin, attached near apical third; duct thin, strongly coiled throughout.  appear in summer between mid June and early July, and are often found on tree blossoms. The larvae bore in freshly dead twigs of Rhaphiolepis indica var. umbellata and Machilus thunbergii (Niisato, 2007). Though not so rare until 1970's, only a few specimens of A. nobuoi nobuoi have been collected since the 1980's. This clytine has been recently treated as "Data Deficient", a category of endangered animals in the Japanese Red Data Book (Ministry of the Environment, Japan, 2007).
This species is somewhat similar in external morphology to A. setiger sp. n. from Taiwan, but can be easily distinguished from the latter by the elytra lacking erect long pale hairs and quite different structure of the male genitalia. Akuseki-jima Is., Tokara Isls., N. Ryukyus, Kagoshima Pref., Japan.
Geographical distribution. Tokara Isls. (Akuseki-jima Is.), Ryukyus, Japan. except for yellowish-brown tarsi, mouthparts, except for black mandibles, yellowishbrown. 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 ♂.
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. Geographical distribution. Taiwan.
Comments. Amamiclytus subnitidus Holzschuh is closely related in external morphology and pubescent maculation to A. 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. Description. Male and female. Body length (from vertex to elytral apices) 3.3-4.4 mm in ♂, 3.6-4.2 mm in ♀. Colour nearly same as A. subnitidus, though strongly glossy. Hairs almost as in A. subnitidus, though partly, sparsely provided with erect long pale hairs, especially on elytra and hind tibia; head sparsely with pale hairs, very thinly with pale gray pubescence on frons in both sexes; Pb as in A. subnitidus, though sparser; scutellum completely bare; elytra thinly with pale short pubescence, provided with a few erect very long pale hairs, with maculation almost as in A. subnitidus, though B and Lp more sparse; venter of thoraces basically similar to that of A. subnitidus, though Ps more sparse near basal half, Mta dense and entire on apical third of metepisternum; V1-V3 almost as in A. subnitidus; hind tibia densely with erect long pale hairs.
Head similar to A. subnitidus, though frons almost as wide as long, slightly convex, with a weaker median line, clypeus  subnitidus, though femur more strongly swollen in apical half, with 1st tarsal segment 1.7-2.3 times as long as the following two segments combined.
Male genitalia. Basically similar to that of A. subnitidus, though median lobe larger and more slender, nearly 3/5 the length of elytra. Median lobe moderately elongate; dorsal plate almost equal in width to or a little shorter than ventral plate, distinctly narrowed to apex which is bluntly prominent; ventral plate almost parallel-sided near basal sixth then gently narrowing to apex, and strongly narrowed to near apical fourth, which is very prominent at the extremity, weakly reflexed in profile; median struts long and slender, almost 3/5 the length of median lobe. Endophallus densely provided with mediumsized spinous spicules behind crescent-like sclerites at a level between basal 3/10 and 3/5, densely covered with minute notched spicules on apical third. Tegmen more or less elongate, distinctly shorter than median lobe; parameres moderately wide, slightly elongate, almost 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 short and a few long setae; basal ridge moderately raised; ring part almost parallel in basal 2/5. Eighth tergite almost quadrate, gently narrowed to apex in apical 3/5, almost transverse at apical margin, provided with numerous short setae. Eighth sternite transverse, almost 1/5 the length of median lobe, distinctly emarginate at apical margin.
Female genitalia. Almost as in A. subnitidus, though bursa copulatrix weakly constricted in basal half, spermathecal duct more strongly coiled in apical half.  2♂♂, 1967, no further data; 1♀, 1967, no further data; 1♂, 1969, no further data. 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. Amamiclytus setiger sp. n. is a distinctive species in having a very glossy body with erect, long, pale hairs especially on the elytral surface, and easily distinguished from the other members of the Taiwanese Amamiclytus. Concerning the morphology of male genitalia, this new species and A. subnitidus Holzschuh share several structures such as the distinctly long median struts, the ratio of the length between parameres and tegmen which is nearly half in length, similar forms of abdominal segment 8, and the similar pattern of spinous spicules behind crescent-like spicules on the endophallus. In female genitalia, the two species also have similar structure as shown in the above description. Therefore, these two species seem to form a species-group among the Taiwanese members of the genus.
This new species mainly appears in the summer season since most of the type series were collected in July, except for several paratypes collected in April and May.
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. 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.

Comments.
In having the matted body with similar pattern of white pubescent maculation on the elytra, A. nubilus sp. n. is somewhat similar to A. juni and A. 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 A. subnitidus Holzschuh and A. 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 A. 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 A. 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 A. nubilus sp. n. has the closest relationship with A. 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.
Amamiclytus juni sp. n. urn:lsid:zoobank.org:act:8260813A-D8BC-44E9-92E6-3BC303BFEF95 http://species-id.net/wiki/ Amamiclytus_juni  Figs 17-18, 38, 65-70 Description. Male and female. Body length (from vertex to elytral apices) 3.40-4.70 mm in ♂, 3.70-5.20 mm in ♀. Colour black, more or less matted in general, dark brown on antennae, meso-and metathoraces, abdomen and legs, yellowish brown on mouthparts except for black mandibles. Body densely clothed with fine pale pubescence especially on pronotum and ventral surface, sparsely with erect long pale hairs on clypeus, genae, pronotal base, prosternal process and abdominal ventrites, mid and hind femora; head sparsely with pale gray pubescence on frons in ♂, sparsely so on that of ♀; antennae with long pale brown hairs along undersides of segments 2-4; pronotum densely with pale gray pubescence except for middle of disc forming a vague oblong black spot, Pb absent; scutellum thinly with pale pubescence; elytra densely with light brown pubescence throughout, B absent, S on basal eighth longitudinally oblong, La on basal 2/5 obliquely arcuate, usually attaining S, Lp on apical 2/5 almost complete, narrow, slightly arcuate, A rather narrow; Ps sparse near basal 2/3, Msl distinct, Mss completely absent, Mta rather sparse along posterior margin of metasternum, dense and entire on apical half of metepisternum; V1 widely separated at sides, dense though narrowed inwards, V2 feeble and sometimes disappeared.
Head across eyes almost as wide as pronotum, HW/PW 0.81-0.94 (M 0.88) in ♂, 0.80-1.00 (M 0.89) in ♀; frons as long as wide, arcuately dilated apicad, with a thin feeble smooth median line, densely, finely punctured; clypeus slightly convex; vertex raised towards antennal cavities which are separated from each other by half the width of occiput; occiput distinctly convex, rather densely coarsely punctured. Antennae thin and relatively short, gradually thickened apicad, attaining apical 2/5 in ♂ or half in ♀ of elytra; 3rd segment 1.4-2.0 times as long as 4th segment, terminal segment rather short and rounded at apex in ♂. Elytra relatively short, EL/EW 2.25-2.75 (M 2.46) in ♂, 2.08-2.90 (M 2.40) in ♀; sides with strongly rounded humeri, gently arcuate at a level between basal and apical fourth, then arcuately narrowed to apices which are slightly arcuate, without any spine at outer or inner angle; disc almost evenly convex, though distinctly depressed near suture in basal fifth, densely provided with fine shallow punctures.
Ventral surface almost smooth, provided with a few coarse punctures on prosternum, with densely minute punctures on meso-and metathoraces, and abdomen; anal ventrite in ♂, 2/5 the length of basal width, distinctly arcuate at apical margin.
Legs relatively short and slender; hind legs 1.4-1.6 times as long as elytra, with femur gradually swollen apicad, exceeding elytral apex at apical fifth, 1st tarsal segment 1.5-2.0 times as long as the following two segments combined.
Male genitalia. Median lobe almost 1/3 the length of elytra, slightly arcuate in profile; dorsal plate slightly wider than ventral plate in apical eighth, rounded at apex; ventral plate almost parallel-sided in basal 3/4 then strongly narrowed to apex which is sharply pointed at the extremity; median struts slender, almost half the length of median lobe. Endophallus largely sparsely provided with minute spinous spicules behind crescent-like sclerites, densely covered with minute crenulate spicules on apical fifth. Tegmen elongate, distinctly shorter than median lobe; parameres narrow, nearly 2/5 the length of tegmen, divided in apical third, with lobe moderately narrowed in weak arcuate line to apex, provided with numerous short setae and a few relatively long setae; basal ridge slightly raised; ring part almost approximate in apical 2/5. Eighth tergite elongate and quadrate, moderately narrowed from apical fourth to apex which is transversely truncate, provided with numerous short to long-sized setae. Eighth sternite distinctly narrower than 8th tergite, apical margin bi-arcuately rounded, triangularly concave near middle.
Female genitalia. Coxite lobe ovoid, provided with a few relatively long setae. Stylus elongate, almost 3/5 in length to coxite lobe, gently dilated apicad. Bursa copulatrix very large, almost circular, though strongly constricted in basal half. Spermatheca relatively narrow, moderately arcuate, bluntly pointed at apex; gland attached at apical third; duct thin, slightly sinuate in basal 2/3, coiled multiple times in apical third.
Comments. Amamiclytus juni sp. n. and the following new species, A. yulongi sp. n. are both short with rounded body with a similar pattern of white pubescence on pronotum, elytra and ventral surface. They form an isolated species group among the Taiwanese members of the genus. These two species are also similar in regards to the male genitalia, for instance, in median lobe with long and shapely pointed ventral plate which is well exposed from ventral view, short and simply pointed lobes of parameres.
Most of the type series of A. juni sp. n. were collected in early spring season in northern and central Taiwan nearly thirty years ago. According to our original field observations, this new species was not so rare and usually found on the blossoms of Castanopsis oak together with the other Amamiclytus species.
Head almost as in A. juni sp. n., though more densely finely punctured, with a thin Ventral surface almost as in A. juni sp. n., though more sparsely punctured on abdomen; anal ventrite in ♂ more or less triangularly produced at middle of apical margin. Legs almost as in A. juni sp. n., though exceeding elytral apices at apical tenth.
Male genitalia. Basically similar to those of A. juni sp. n., though median lobe more slender, with ventral plate not so strongly pointed apicad. Median lobe 1/3 the length of elytra, gently arcuate in profile; dorsal plate slightly wider than ventral plate in apical 3/5, distinctly narrowed to apex which is slightly pointed; ventral plate almost parallel-sided in basal 2/5 then gently narrowed to apex, and strongly narrowed to apical 1/12, which is sharply pointed at the extremity, shortly exposed from ventral view; median struts slender, almost half the length of median lobe. Endophallus densely covered with minute spinous spicules in apical fifth. Tegmen elongate, slightly shorter than median lobe; parameres relatively wide, nearly 2/5 the length of tegmen, divided in apical fifth, with lobe narrowed in gently arcuate line to apex, approximate and subparallel at inner margins, rather narrowly rounded at apex which is provided with numerous short and a few very long setae; basal ridge slightly raised; ring part almost approximate and parallel in apical third. Eighth tergite elongated and quadrate, gently narrowed from apical 3/4 to apex which is gently arcuate, provided with numerous long setae. Eighth sternite transverse, nearly equal in width to 8th tergite, apical margin arcuately oblique towards middle.
Female genitalia. Almost as in A. juni sp. n., though bursa copulatrix smaller, semicircular in apical 2/5, moderately narrowed in basal 3/5.  Mt. Dahan Shan, Chunri Township, alt. 1,200m, 9-III-2006 Geographical distribution. Taiwan. Comments. Amamiclytus yulongi sp. n. is closely related in the external and genitalic morphology to A. juni sp. n., but it can be distinguished from the latter by strongly glossy body, more coarsely punctured pronotum, sparse white pubescence on elytral bases, dense minute spinous spicules on the endophallus, gently arcuate apical margin of 8th tergite and not so strongly constricted basal part of bursa copratrix.
This new species is rather rare among the Taiwanese members of the genus, and sometimes found on the blossoms of Castanopsis and the other tree blossoms.

Amamiclytus hirtipes
Description. Male and Female. Body length (from vertex to apices of elytra) 4.0-5.8 mm in ♂, 4.4-6.0 mm in ♀. Large and slender species with more or less matted body, long antennae and legs. Colour black, relatively matted especially on elytra, more or less brownish on meso-and metathoraces, antennae and legs, yellowish brown on mouthparts except for black mandibles and anal ventrite. Body densely clothed with fine pale pubescence, sparsely with erect, long, pale hairs on undersides of fore femur, apical 2/5 of mid and hind femora, and all tibiae especially on hind pair; head thinly pubescent, scattered with a few erect, long, pale hairs, densely with pale gray pubescence on frons in ♂ and sparsely so in ♀; antennae with relatively long pale brown hairs along undersides of segments 3-5; pronotum thinly pubescent, largely exposing disc, without erect, pale hairs, rather sparsely with white pubescence at sides of basal margin, not formed conspicuous Pb; scutellum with a few pale pubescence; elytra rather densely with pale brown pubescence, without erect, pale hairs, B around scutellum relatively sparse, S on basal eighth small and longitudinally oblong, La on basal 3/10 semicircular, slightly oblique, Lp on apical 3/10 almost complete, narrow, weakly arcuate, A very narrow; prosternum sparsely with white pubescence near middle, Msl and Mss distinct, Mta rather sparse along posterior margin of metasternum, dense and entire on apical 2/3 of metepisternum; V1 and V2 at sides dense though narrowed to middle.
Head across eyes slightly narrower than pronotum, HW/PW 0.89-0.95 (M 0.93) in ♂, 0.85-0.95 (M 0.90) in ♀; frons as long as wide, arcuately dilated apicad, with a fine smooth median line, closely coarsely punctured; clypeus almost flattened; vertex raised towards antennal cavities which are separated from each other by 2/5 the width of occiput; occiput distinctly convex, closely reticulate. Antennae thin and long, not thickened apicad, attaining apical third in ♂ or half in ♀ of elytra, with scape almost cylindrical, 3rd segment 1.4-2.0 times as long as 4th segment, middle segments weakly thickened at apices, terminal segment distinctly elongate in ♂.
Pronotum usually distinctly longer than wide, rather weakly arcuate at sides; PL/ PW 1.05-1. Elytra long, slender, nearly or more than three times as long as wide, EL/EW 2.83-3.60 (M 3.10) in ♂, 2.50-3.05 (M 2.80) in ♀; sides with completely rounded humeri, gently arcuate at a level between basal fourth and apical 2/5 then arcuately narrowed to apices which are obliquely arcuate with blunt teeth at external angles; disc almost evenly convex, closely provided with fine shallow punctures.
Ventral surface almost smooth, provided with a few coarse punctures on prosternum, minute ones on meso-and metathoraces, and abdomen; ♂ anal ventrite 7/10 the length of basal width, weakly arcuate at apical margin.
Legs long and slender; hind legs 1.6-2.0 times as long as elytra, with femur gradually swollen apicad, slightly compressed, exceeding elytral apex at apical fifth, 1st tarsal segment 1.5-2.2 times as long as the following two segments combined.
Male genitalia. Median lobe almost 1/3 the length of elytra, in lateral view almost straight though distinctly bent ventrad in apical 2/5 of apical lobe; dorsal plate almost equal in width to or a little longer than ventral plate, gently narrowed to apex which is bluntly pointed; ventral plate almost parallel-sided in basal 3/4 then gently narrowed to apex which is more or less sharply pointed at the extremity; median struts slender, almost half the length of median lobe. Endophallus sparsely provided with minute spinous spicules behind crescent-like sclerites from basal 1/3 to 7/10, densely covered with minute serrate sclerites in apical fifth. Tegmen elongate, slightly shorter than median lobe; parameres elongate, nearly 2/5 the length of tegmen, divided in apical fifth, with lobe almost parallel-sided, moderately convergent apicad, slightly oblique at inner margins, almost rounded at apices which are provided with numerous short and a few long setae; basal ridge slightly raised; ring part parallel in apical third. Eighth tergite quadrate, arcuate at sides of apical margin which is slightly emarginate, provided with numerous short and long setae. Eighth sternite strongly transverse, rather weakly emarginate at apical margin.

Discussion
In spite of its uniqueness, Amamiclytus Ohbayashi shows relationship in external morphology with the genera Rhaphuma Pascoe, Chlorophorus Chevrolat and Demonax Thomson as follows: 1) body including legs and antennae usually elongate; 2) antennae thin and long, almost exceeding apical halves of elytra in male, with segment 3 longer than scape; 3) eyes large and approximate to each other; 4) genae relatively shallow in frontal view; 5) mandible along inner margin smooth; 5) labial and maxillary palpi has a distinct sexual dimorphism in each terminal segment. Han and Niisato (2009) suggested that the structure of endophallus in male genitalia is one of the important characters to distinguish the genera of the tribe Clytini. Amamiclytus is clearly defined by this character and distinguishable from the other genera of the tribe, though it has a close relationship with the genera Rhaphuma, Chlorophorus and Demonax. These three related genera show the following features on the spicules of their endophallus; 1) Rhaphuma: usually without any spicules near base of endophallus, or weakly, rather sparsely provided with several kinds of spicules on the whole of endophallus; 2) Chlorophorus: densely provided with large-sized sclerotized spicules on the whole of endophallus; 3) Demonax: basically similar to those of Amamiclytus, though has a pair of sclerotized lines consisting of minute or mediumsized spinous spicules on the apical part of endophallus.
A total of seven species of Amamiclytus from Taiwan and the Ryukyu Islands of Southwest Japan are provisionally divided into four morphological groups mainly based on both the male and female genitalia as follows.
general appearance to A. hirtipes except for the presence of a distinct basal band on pronotum ("Pb") and the absence of basal bands near elytral bases ("B"). Spermatheca of female genitalia is strongly arcuate, with simple, not coiled duct. Also, the male genitalia are basically similar in the proportion of median struts and parameres to the Group I, though the median lobe is not so elongate and the ring part of tegmen is not expanded apicad as in those of Group I.
Group III composed of A. juni and A. yulongi, is characterized by short, broadened and matted body, rather transverse pronotum with distinctly arcuate sides, without white pubescence near the basal margin. The independence of this group is strongly supported by the structures of both male and female genitalia. In the female genitalia, the coxite lobes are long, about twice the length of stylus, spermathecal duct is strongly coiled in apical third, and bursa copulatrix is very large. It has the shortened male genitalia, of which the median struts are half the length of median lobe, and the parameres are 2/5 the length of tegmen.
Group IV is also monotypic at least in the present sense, composed of a single species, A. hirtipes, and is clearly distinguished from the other groups of the genus by very large and slender body on average, with sparse "Pb" on the pronotum and without "B" on the elytra. However, A. hirtipes has close relationship in female genitalia with A. nubilus; spermatheca is strongly curved near middle, with gland attached at the middle of spermatheca, and the duct is not coiled, only weakly sinuate throughout. Male genitalia of A. hirtipes are also similar to those of A. nobuoi (Group I), and A. juni and A. yulongi (Group III).