Zootaxa 1325: 157–190 (2006) ISSN 1175-5326 (Print Edition) ZOOTAXA 1325 Copyright © 2006 Magnolia Press ISSN 1175-5334 (Online Edition)

Geographic variation of chromosomes and somatic morphology in the Japanese polymorphic species Leiobunum hiraiwai (Arachnida: Opiliones: Sclerosomatidae)

NOBUO TSURUSAKI Laboratory of Biology, Faculty of Regional Sciences, Tottori University, Tottori, 680-8551 Japan. E-mail: [email protected]

Abstract

The hiraiwai-subgroup of the Leiobunum curvipalpe-species group (Opiliones: Sclerosomatidae: Leiobuninae) is revised on the basis of somatic morphology, genitalia and karyotypes. This subgroup is distributed mainly in the mountainous areas of the Japanese Beech (Fagus crenata) forest zone (usually above 700 m in altitude in the southwestern part of Japan) in the western part of the Japanese Islands and corresponds to a single polytypic species, Leiobunum hiraiwai (Sato & Suzuki, 1939) with eight geographic races. Leiobunum tamanum Suzuki, 1957 and L. tsushimense Suzuki, 1976 are here synonymized with L. hiraiwai. All the races, except for the Tsushima race, were chromosomally analyzed. The number of chromosomes varies geographically from 2n = 18 to 22 eastwards, irrespective of the variation in somatic morphology or male genitalia. Component chromosomes in these karyotypes are invariably metacentric or submetacentric in structure. Some morphological characters show a geographic pattern of variation that conforms to the stasipatric model of speciation. The possible processes of geographical differentiation of the species and direction of character evolution are inferred on the basis of such geographical patterns. The distribution of some character states suggests that the closest relative of the subgroup is the curvipalpe-subgroup (= Leiobunum curvipalpe Roewer, 1910 and L. tohokuense Suzuki, 1976) that inhabits the northeastern part of Honshu, Japan. The hiraiwai-subgroup (= Leiobunum hiraiwai) shows a mutually exclusive or checkerboard pattern of geographical distribution with regards to the montanum-subgroup (= Leiobunum montanum Suzuki, 1953) in southwestern Japan, suggesting some possible reproductive interference between these two species.

Key words: Checkerboard distribution, chromosomes, genital morphology, geographic variation, Japan, new synonymy

Accepted by P. Schwendinger: 25 Jul. 2006; published: 28 Sept. 2006 157 ZOOTAXA Introduction 1325 In the fourth of a series of papers (Tsurusaki 1985a, 1985b, 1990) dealing with the taxonomic revision of the Leiobunum curvipalpe-group (Arachnida: Opiliones), I will present here a taxonomic revision of the hiraiwai-subgroup of the curvipalpe-species group with a general account of its geographic variation in somatic morphology, male genitalia and karyotypes. This subgroup, which is treated here to include only a single species Leiobunum hiraiwai (Sato & Suzuki, 1939) after placing L. tamanum Suzuki 1957 and L. tsushimense Suzuki 1976 into the synonymy of L. hiraiwai, is distributed in the southwestern half of the Japanese Islands. The curvipalpe-subgroup (L. curvipalpe Roewer, 1910 and L. tohokuense Suzuki, 1976) occupies the northeastern half of Honshu, Japan. Leiobunum hiraiwai usually occurs in mountainous areas above 700 m, in altitude where Japanese Beech (Fagus crenata) predominates in the forests in southwestern Honshu and Kyushu. It can also be found in subalpine coniferous forests above ca 2000 m in altitude in the northern Kantô district, where L. curvipalpe occupies lower beech forests. Interestingly, two common species of this group in western Japan, L. hiraiwai and L. montanum, rarely overlap in their distributional ranges. I will also discuss the possible reason for the mutually exclusive pattern of distribution in the Leiobunum curvipalpe- group.

Material and methods

A total of 1963 specimens (1595%, 313&, 55juv.) collected from 152 localities were used in the examination of somatic morphology. In 19 populations covering 7 races chromosomes were surveyed by a squash method using acetic-orcein (preparations done in 1981) and an air-drying method (preparations from 1982 to 1996). The description of the air-drying techniques can be found in Tsurusaki (in press). Descriptions are given according to the format used in Tsurusaki (1985a). All measurements are in mm. Abbreviation: BL = body length, FIL = femur I length, NT = N. Tsurusaki, PaL = palp length (= femur+patella+tibia+tarsus), PrL = prosoma length, SC = Dr Seisho Suzuki’s personal collection, ZLHU = Zoological Laboratory, Faculty of Science, Hiroshima University, Hiroshima. All the specimens examined are listed under “Specimens examined”. In the list, data for each sample are given by the following order: locality, altitude and forest vegetation (Cj = Cryptomeria japonica, Japanese Red Cedar; Fc= Fagus crenata) if available, number of individuals (the number of specimens dissected for chromosome observation are in parentheses with “Chrom. Obs.” or “CH”. Chromosomes of the specimens marked “CH.” alone are to be reported elsewhere. The number marked “Chrom. Obs.” may be unequal to the one in Table 1, since we failed to obtain countable chromosomal spreads for some individuals), date collected, collector (NT = Nobuo Tsurusaki).

158 © 2006 Magnolia Press TSURUSAKI TABLE 1. Chromosome numbers in various populations of Leiobunum hiraiwai. ZOOTAXA 1325 Race1) Locality2) Collecting date Individuals Chromosome FN4) (or reference) examined3) number (2n) % & KH Mt Hiko (2) (Suzuki 1957) - 18 - - KH Mt Hiko (2) 30/31 July 1982 6% 18 - 36 KI Mt Hyônosen (Suzuki 1980) - 20 - - KI Mt Bunagatake (Hira) (10) 13 Aug 1982 6% 20 - 39, 40 KI Mt Ontake, Hakkaisan (17) 29/30 July 1981 2%*20-- KA Kamikôchi, Konashidaira (26) 28/29 July 1981 8%*20-- KA Kamikôchi, Yokoo Hütte (28) 27 July 1981 6%*20-- KA Ariake Spa (29) 17 Aug. 1982 4% 20 - - KI Tsuetsuki Pass (22) 20 Aug. 1982 2% 20 - 40 Int Ina-Todai (59) 20 Aug. 1982 1% 20 - 40 Int Mt Nyûgasa (58) 21 Aug. 1982 5% 20 - 40 U Yashajin Pass (46) 6 Aug. 1980 5%*20-- U Kowashimizu 1630 m alt. 8 July 1982 9juv.(5%4&) 20 20 40 (44), Kirigamine campground U Kowashimizu 1660 m alt. (45) 8 July 1982 3% 20 - 40 U Mt Utsukushigahara, 19 Aug. 1982 6% 20 - 40 Yamamoto Hütte (42) WK Togakushi-Chûsha (50) 23 July 1980 7%*20-- WK Mt Bushû-Mitake (57) (Suzuki 1957) - 22 - - WK Mt Bushû-Mitake (57) 23 July 1982 7% 22 - 44 F Lake Kawaguchi (31) 2 Aug. 1981 6%*20-- F Mt Kiyosumi (42) 27 Aug. 1984 8% 22 - 44 F Mt Kiyosumi (42) 26 Aug. 1996 2% 22 - 44 I Mt Amagi (40) 24 July 1982 6% 22 - 44

1) Races defined mainly by penis morphology: KH = Kyushu-Hiroshima; KI = Kinki; KA = Kamikôchi; Int = intermediate populations between Kinki and Utsukushigahara races; U = Utsukushigahara; WK = Western Kantô; F = Fuji; I = Izu 2) Numerals in parentheses denote locality numbers given in Fig. 7. 3) Asterisked = prepared by squash method. 4) FN = fundamental number, which means the total number of chromosomal arms in the complement.

Leiobunum hiraiwai (Sato & Suzuki, 1939) Figs 1–18

FIGURES 1A–L. Leiobunum hiraiwai (Sato & Suzuki). A–B. Eye tubercle of male, lateral view. C–F. Genital operculum (C–D male, E–F female). G–H. Labrum of female, lateral view. I-K. Chelicera of male, mesal view. L. Body of female, dorsal view. Localities (numerals in parentheses denote code numbers given in Fig. 7): A. Mt Bunagatake (10 — Kinki race). B, J. Mt Utsukushigahara (42 — Utsukushigahara race). C. Mt Hyônosen (8 — Kinki race). D, K. Mt Amagi (40 — Izu race). E, G, L. Kisokoma-kôgen (15 — Kinki race). F, H. Togakushi (50 — Western Kantô race). I. Mt Hiko (2 — Kyushu-Hiroshima race).

Nelima hiraiwai Sato & Suzuki, 1939: 38, figs 3–4. (Type locality: Mt Hikosan, Kyushu, Japan). Liobunum hiraiwai: Suzuki 1953, figs 4–5; 1957: 109, figs 9–12, 15, 18, 21. Leiobunum hiraiwai: Suzuki 1966: 160, figs 2F, H: 3F; Tsurusaki & Sasaji 1991: 16, fig. 7C; Tsuru- saki 1993: 214; Tsurusaki & Okada 2000: 73, fig. IV-11 (left); Tsurusaki 2002a: 92. Leiobunum hiraiwai hiraiwai: Suzuki 1976: 237, figs 48–50, 110–111, 252–254, 269, 345–347. Leiobunum hiraiwai izuense Suzuki, 1976: 239, figs 51–52, 112, 256–257, 270–274, 348–350. (Type locality: Mt Yahazu-yama, Shizuoka Pref.) Leiobunum hiraiwai fuji Suzuki, 1976: 241, figs 53-58, 113-115, 277-280, 351-352. (Type locality: Lake Yamanaka, Yamanashi Pref.).

160 © 2006 Magnolia Press TSURUSAKI Leiobunum hiraiwai shiranense Suzuki, 1976: 244, figs 59–60, 116, 255, 275–276. (Type: % holo- ZOOTAXA type and 1& paratype, Shiranesanzan, from Mt Aino-dake to Mt Nôtori-dake, Yamanashi Pref., 1325 Z. Ôshimo leg., 27. August 1953, in ZLHU, examined). Leiobunum hiraiwai longum Suzuki, 1976: 244, figs 61–64, 117, 261–263, 281–284, 353–355. (Type locality: Mt Hyônosen, Tottori Pref.). Liobunum tamanum Suzuki, 1957: 113, figs 1–3, 5–8, 16, 19, 22, 24–25. (Type locality: Mt Bushû- Mitake, Tokyo Pref.). NEW SYNONYMY. Leiobunum tamanum: Suzuki 1976: 232, figs 72–73, 124, 239–244, 340–341; Tsurusaki & Hayashi 1985: 509. Leiobunum tsushimense Suzuki, 1976: 234, figs 65–66, 245–251, 342–344. (Type: % holotype from Mt Ariake-yama, Tsushima Is., Nagasaki Pref., 7. July 1973, S. Suzuki leg., in ZLHU, examined). NEW SYNONYMY.

FIGURES 2A–Q. Leiobunum hiraiwai (Sato & Suzuki). Labrum of male, lateral (above) and ventral (below) views. Races: A. Tsushima race. B–D. Kyushu-Hiroshima race. E–G. Kinki race. H–I. Kamikôchi race. J–K. Fuji race. L–M. Izu race. N–O. Utsukushigahara race. P–Q. Western Kantô race. Localities: A. Mt Ariake (1). B. Mt Hiko (2). C. Yoshiwa-mura (4). D. Sandankyô (5). E. Mt Hyônosen (8). F. Mt Bunagatake (10). G. Tsuetsuki-tôge (22). H. Suzuran (25). I. Kamikôchi (26). J. Lake Kawaguchi (31). K. Tanzawa (35). L. Mt Takanosu (36). M. Mt Amagi (40). N. Mt Utsukushigahara (42). O. Mt Nôtori to Mt Ainodake (48). P. Kurumasaka-tôge Pass (51). Q. Mt Bushû-Mitake (57). Numerals in parentheses denote code numbers of localities given in Fig. 7.

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 161 ZOOTAXA Diagnosis. Characterized by the unique shape of the penis shaft with laterally expanded 1325 projections (winglets); winglets often barbed (Nos 2–9 in Fig. 16). Palps of both males and females often darkened (This character state is only shared by L. curvipalpe Roewer, 1910; see Tsurusaki 1990).

FIGURES 3A–I. Leiobunum hiraiwai (Sato & Suzuki), palp of male, mesal view. Races: A. Kyushu-Hiroshima race. B–C. Kinki race. D. Kamikôchi race. E. Fuji race. F. Utsukushigahara race. G–H. Western Kantô race. I. Izu race. Localities: A. Mt Hikosan (2). B. Mt Bunagatake (10). C. Tsuetsuki-tôge (22). D. Kamikôchi (26). E. Lake Kawaguchi (31). F. Mt Utsukushigahara (42). G. Kurumasaka-tôge (51). H. Mt Bushû-Mitake (57). I. Mt Amagi (40). Numerals in parentheses denote code numbers of localities given in Fig. 7.

Description. Male. With medium to large-sized body (3.3–5.9 mm long). Genital operculum as shown in Figs 1C–D, boundary between operculum and 3rd sternite somewhat obscure. Labrum as in Fig. 2, club-shaped, laterally with numerous dark tubercles. Chelicera as in Figs 1I–K, second segment with a few black teeth on its distomesal surface. Palp as shown in Fig. 3; femur moderately curved ventrad, distolaterally with a few teeth; patella distally widened, with a small but distinct apophysis on mesal distal margin; tibia proximally swollen, ventromesally with numerous dark teeth in distal third; tarsus with a distinct ventromesal row of teeth. Palps often completely (Figs 3C–F) or partially (Fig. 3B) darkened; degree of the melanism varying geographically (Fig. 4).

162 © 2006 Magnolia Press TSURUSAKI Penis as in Figs 8–16; shape and size variable among populations; shaft widest at base ZOOTAXA and gradually narrowing toward apex but expanded distally; lateral projections at distal 1325 end of shaft ventrally forming a pair of pouches. Female. Labrum as shown in Figs 1G–H, gradually tapering. Genital operculum (Figs 1E–F) with posterior margin weakly delimited and sharply rounded.

FIGURE 4. Frequencies of dark-colored and light-colored palps in males of Leiobunum hiraiwai. The upper left box shows different grades of melanism for palpal patella (Pa) and tibia (Ti) in lateral view, which corresponds to the shading of the circles. 1. Light colored. 2–3. Intermediate condition (corresponding to stippled section of circles). 4–5. Dark colored.

Karyotypes (Figs 5–6). Suzuki (1980) briefly reported the existence of three different karyotypes in “L. hiraiwai”, which were easily separable by the number of chromosomes (2n = 18, 20 and 22, respectively). To ascertain this, a total of 99 individuals collected from 19 populations were karyologically analyzed by two methods (squash and air- drying). Provenance of material and the results obtained are synoptically presented in Table 1. Chromosomes were found to vary in number and in morphology among the populations examined. This phenomenon was already reported by Suzuki (1980). Interestingly, an obvious eastward increase in the number of chromosomes from 2n = 18 (Mt Hikosan population) to 2n = 22 (Mt Bushû–Mitake, Mt Amagi and Mt Kiyosumi

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 163 ZOOTAXA populations) was observed (see Figs 7, 17). Of diploid complement, the X and Y 1325 chromosomes were usually the largest or the smallest chromosomes, respectively, although some variants were found. Characteristics of these karyotypes are mentioned in the descriptions of races below.

FIGURES 5A–E. Male karyotypes of Leiobunum hiraiwai. Races: A. Kyushu-Hiroshima race. B–C. Kinki race. D–E. Intermediate populations. Localities: A. Mt Hikosan (2n = 18). B. Mt Bunagatake (2n = 20). C. Tsuetsuki-tôge Pass (2n = 20). D. Todai (2n = 20). E. Mt Nyûgasa (2n = 20).

Geographic variation and races

Suzuki (1976) recognized five taxa in this species on the basis of differences in the shape of the penis, and described them as subspecies of L. hiraiwai (Sato & Suzuki). Later, he found that three of the five subspecies (L. h. hiraiwai, L. h. longum and L. h. izuense) are distinguishable from one another by the number of chromosomes and briefly suggested that they should be treated as distinct species (Suzuki 1980). However, as mentioned in the first paper of the present series (Tsurusaki 1985a), it is improper to divide allopatric (or parapatric) populations of closely related forms into independent species on the basis of different chromosome numbers per se. Introgression of genes among chromosomal races through the hybrid zones is not a rare phenomenon in various organisms (see extensive reviews by White 1978; Key 1981; King 1993) and formation of an extensive

164 © 2006 Magnolia Press TSURUSAKI chromosomal hybrid zone between two forms having enormously different chromosome ZOOTAXA numbers (2n = 16 and 2n = 22) is well-documented even in harvestmen (Gagrellopsis 1325 nodulifera Sato & Suzuki) by Tsurusaki et al. (1991) and Gorlov & Tsurusaki (2000). Moreover, in L. hiraiwai morphological divergence in somatic characters among three forms having different number of chromosomes (Kyushu-Hiroshima race = L. h. hiraiwai / Kinki race = L. h. longum / Izu race = L. h. izuense) is smaller than among chromosomally less variable forms (Kinki race / Utsukushigahara race = L. tsushimense, or Izu race / Western Kantô race = L. tamanum). Therefore I do not treat these geographic forms with different numbers of chromosomes as different species.

FIGURES 6A–E. Male karyotypes of Leiobunum hiraiwai. Races: A. Kamikôchi race. B–C. Utsukushigaraha race. D. Western Kantô race. E. Izu race. Localities: A. Ariake Spa (2n = 20). B. Mt Utsukushigahara (2n = 20). C. Kowashimizu, 1630 m alt., Mt Kirigamine (2n = 20). D. Mt Bushû-Mitake (2n = 22). E. Mt Amagi (2n = 22).

On the other hand, L. tamanum Suzuki and L. tsushimense Suzuki have been regarded each as a species constituting one monophyletic subgroup different from “L. hiraiwai”. In the course of a survey of their distributions in the Chûbu district of Honshu, however, I have collected numerous male specimens whose penes show all gradations between typical L. tsushimense and typical L. hiraiwai from the two populations on Mt Kirigamine (see description of the Utsukushigahara race). Therefore it is very likely that gene flow between “L. hiraiwai” and “L. tsushimense” is not restricted. The occurrence of L. tsushimense at two very distant localities, Is. Tsushima (Loc. No. 1 in Fig. 7) and Mt Utsukushigahara in central Honshu (Loc. No. 42 in Fig. 7) has so far been a perplexing

FIGURE 7. Distribution and chromosome numbers of eight races of Leiobunum hiraiwai. Localities: 1. Mt Ariake, Is. Tsushima. 2. Mt Hikosan. 3. Is. Miyajima. 4. Yoshiwa-mura. 5. Sandankyô. 6. Mt Shiraki. 7. Mt Azuma. 8. Mt Hyônosen. 9. Mt Hieizan. 10. Mt Bunagatake. 11. Mt Ibuki. 12. Mt Gozaisho. 13. Mt Hakusan. 14. Mt Hoko. 15. Kisokoma-kôgen. 16. Kôzenji, Kisofukushima. 17. Mt Ontake. 18. Narai. 19. Mt Kokuzô. 20. Kôzenji, Komagane. 21. Ina-Takatô. 22. Tsuetsuki-tôge Pass. 23. Mt Kirigamine, Ikenokurumi. 24. Sakai-tôge Pass. 25. Suzuran, Mt Norikura. 26–28. Kamikôchi (26 Konashidaira, 27 Myôjin, 28 Yokoo Hütte). 29. Ariake Spa. 30. Nakabusa Spa. 31. Lake Kawaguchi. 32. Lake Yamanaka. 33. Fuji-Yoshida. 34. Mt Kintoki, Hakone. 35. Yabitsu-tôge Pass. 36. Mt Takanosu, Hakone. 37. Lake Ashinoko, Hakone. 38. Mt Yahazu. 39. Mt Tôgasa. 40. Mt Amagi. 41. Amagi-tôge Pass. 42. Mt Utsukushigahara. 43. Tobira-tôge Pass. 44–45. Mt Kirigamine, Kowashimizu, populations at 1630–1660 m. 46. Yashajin-tôge Pass. 47. Hirogawara, Mt Kitadake. 48. Mt Nôtori to Mt Ainodake. 49. Umegashima Spa. 50. Togakushi- kôgen. 51. Kurumasaka-tôge Pass. 52. Mt Haruna, Haruna Shrine. 53. Mt Hiuchi-ga-take. 54. Yumoto Spa, Nikko. 55. Daibosatsu-tôge Pass. 56. Nippara, Okutama. 57. Mt Bushû-Mitake. Dotted line indicates distribution areas of cool temperate broad-leaved forest (mainly beech).

FIGURES 8A–E. Leiobunum hiraiwai, penis, ventral (left) and lateral view (right). Races: A. Tsushima race. B–E. Kyushu-Hiroshima race. Localities: A. Mt Ariake, Is. Tsushima (1). B. Mt Hikosan (2). C. Yoshiwa-mura (4). D. Sandankyô (5). E. Mt Azuma (7). Numerals in parentheses denote code numbers of localities given in Fig. 7. problem, as stated by Suzuki (1976). However, if we regard these two distant populations of L. tsushimense as geographical isolates belonging to L. hiraiwai, it is no longer a puzzle, because many other populations of this species occur between these two distant localities. Leiobunum tamanum from Mt Bushû-Mitake (No. 57 in Fig. 7, the type-locality) is clearly distinguishable from L. tsushimense from Mt Utsukushigahara by the shape of the penis (compare Figs 15G and 14F), as well as by different numbers of chromosomes (2n = 22 in the former, 2n = 20 in the latter). However, these two “species” are linked by intermediate populations between the northern part of Chûbu and the northern Kantô Districts. Therefore both L. tamanum and L. tsushimense are here considered as races of “L. hiraiwai”. The system adopted in the present paper and that of Suzuki (1976) is summed up in Table 2.

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 167 ZOOTAXA The holotype of L. hiraiwai Suzuki belongs to the Kyushu-Hiroshima race of the 1325 present study. Diagnoses of the races and some notes on their distributions and natural histories are separately presented below.

FIGURES 9A–E. Leiobunum hiraiwai, penis, ventral (left) and lateral view (right), Kinki race. Localities: A. Mt Hyônosen (8). B. Mt Bunagatake (10). C. Mt Ibuki (11). D. Mt Gozaisho (12). E. Mt Hakusan (13). Numerals in parentheses denote code numbers of localities given in Fig. 7.

168 © 2006 Magnolia Press TSURUSAKI TABLE 2. Synopsis of the systems adopted by Suzuki (1976) and used in the present paper. ZOOTAXA 1325 Suzuki (1976) present paper L. hiraiwai (Sato & Suzuki) L. tsushimense Suzuki (in part) Tsushima race L. hiraiwai hiraiwai (Sato & Suzuki) Kyushu-Hiroshima race L. hiraiwai longum Suzuki Kinki race L. hiraiwai fuji Suzuki Kamikôchi race Fuji race L. hiraiwai izuense Suzuki Izu race L. tsushimense Suzuki (in part) Utsukushigahara race L. hiraiwai shiranense Suzuki L. tamanum Suzuki Western Kantô race - intermediate populations

FIGURES 10A–E. Leiobunum hiraiwai, penis, ventral view (left) and tip of penis, lateral view (right), Kinki race. Localities: A. Mt Hoko (14). B. Kisokoma-kôgen (15). C. Mt Ontake (17). D. Narai (18). E. Mt Kokuzô (19). Numerals in parentheses denote code numbers of localities given in Fig. 7.

Leiobunum tsushimense Suzuki, 1976: 234, figs 65, 247–249, 344.

Diagnosis. This race shows closest affinities to the Kyushu-Hiroshima race in the shape of the labrum and palp but it is clearly distinguishable from the latter by the penis lacking lateral barbs on the posterior angles of the distal swelling of the shaft. In the shape of the penis, it shows a close similarity to some populations of the Utsukushigahara race (compare Figs 8A and 14D, F). However, unlike the Utsukushigahara race, this race has bright colored palps and a slender labrum (Fig. 2A). Distribution. Is. Tsushima (Fig. 7)

FIGURES 11A–F. Leiobunum hiraiwai, penis, ventral (left) and tip of penis, lateral view (right). Races: A–D. Kinki race. E–F. Intermediate populations. Localities: A. Komagane-Kôzenji (20). B. Takatô (21). C. Tsuetsuki-tôge Pass (22). D. Ikenokurumi (23). E. Todai (59). F. Mt Nyûgasa (58). Numerals in parentheses denote code numbers of localities given in Fig. 7.

Nelima hiraiwai Sato & Suzuki, 1939: 38, figs 3–4. Leiobunum hiraiwai: Suzuki 1953: 181, figs 4E, K–O, 5D–F; 1957: 109, figs 9–12, 15, 18, 21. Leiobunum hiraiwai: Suzuki 1966: 160, figs 2F, H, 3F. Leiobunum hiraiwai hiraiwai: Suzuki 1976: 237, figs 48–50, 110–111, 252–254, 264–269, 345–347; 1986: 27, figs 34–35; Suzuki & Tsurusaki 1977: 392.

FIGURES 12A–F. Leiobunum hiraiwai, penis, ventral (left) and lateral view (right). Races: A–D. Kamikôchi race. E–F. Fuji race. Localities: A. Sakai-tôge Pass (24). B. Suzuran (25). C. Kamikôchi (26). D. Ariake Spa (29). E. Lake Kawaguchi (31). F. Tanzawa (35). Numerals in parentheses denote code numbers of localities given in Fig. 7.

Diagnosis. Characterized by the slender labrum (Figs 2B–D) and bright colored palps (Fig. 3A). Distinguishable from the Tsushima and Kinki races by the shape of the penis, having lateral barbs on the distal winglets, and a non-elongated shaft. In the general shape and size of the penis this race is similar to both the Kamikôchi race (No. 7 in Fig. 16) and the Izu race (No. 9 in Fig. 16). Minor differences in the distal winglets of the penial shaft may serve to discriminate these races. Karyotype (Fig. 5a). 2n(%) = 18 (Mt Hikosan; population No. 2 in Table 1 and Fig.

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 171 ZOOTAXA 7). The autosomes are composed of 7 pairs of similar-sized metacentrics and a pair of 1325 submetacentrics (chromosome 3). The X chromosome is large and submetacentric, while the Y is the smallest chromosome and metacentric. Distribution. Northern Kyushu (Mt Hikosan) and mountainous areas of Hiroshima Prefecture in the westernmost part of Honshu. The distribution of this race seems to correspond roughly to that of Japanese Beech (Fagus crenata) forests in these areas. Consequently the distributional range can be recognized as only an assemblage of several geographical isolates (Fig. 7). Biology. This race is sympatric with L. hikocola Suzuki 1966 on Mt Hikosan, northern Kyushu. Adults are usually found on trunks of trees, mainly in woodlands of beech or Japanese red cedar (Cryptomeria japonica), from early July to September.

FIGURES 13A–G. Leiobunum hiraiwai, penis, ventral (left) and lateral view (right). Races: A–C. Izu race. D–G. Utsukushigahara race. Localities: A. Mt Takanosu (36). B. Mt Amagi (40). C. Amagi-tôge Pass (41). D–E. Umegashima Spa (49). F. Mt Nôtori to Mt Ainodake (48). G. Mt Kitadake, Hirogawara (47). Numerals in parentheses denote code numbers of localities given in Fig. 7.

Leiobunum hiraiwai longum Suzuki, 1976: 244, figs 61–64, 117, 261–263, 281–284, 353–355. Leiobunum hiraiwai (Kinki race): Tsurusaki & Sasaji 1991: 16, fig. 7C. Leiobunum hiraiwai: Tsurusaki 1993: 214; Tsurusaki 2002a: 168, fig. 1. Leiobunum hiraiwai (Mt Kenashi race): Tsurusaki & Okada 2000: 73, fig. IV-11(left).

Diagnosis. Race with characteristically elongated and strongly curved penis in lateral view (Figs 9–10, 11A–D). Also characterized by its relatively large body and well developed dark brown palps. Unlike in the Kyushu-Hiroshima race, the labrum is considerably swollen in the middle (Figs 2E–G).

FIGURES 14A–F. Leiobunum hiraiwai, penis, ventral (left) and lateral view (right), Utsukushigahara race. Localities: A. Yashajin-tôge Pass (46). B–D. Mt Kirigamine, Kowashimizu, 1660 m alt. (45). E. Tobira Pass (43). F. Mt Utsukushigahara (42). Numerals in parentheses denote code numbers of localities given in Fig. 7.

The shape of the distal winglets of the penial shaft suggests that this race can be subdivided into three local subraces. Namely, specimens from the Kinki District to the valley of the Kiso River have penes whose distal swelling is armed with two pairs of prominent barbs (Figs 9, 10C–D). However, specimens from the Tenryû River (= Ina-dani)

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 173 ZOOTAXA valley have usually only one pair on the corresponding part (Figs 10E, 11A–D). On the 1325 other hand, specimens from the other two populations (Mt Hoko and Kisokoma-Kôgen), located in the southern part of the Kiso Valley, are similar to the Ina-dani populations in lacking the second pair of spines on their penes, but can be distinguished from the latter by the shape of the pouches in the distal swelling and conspicuously shorter barbs of the penis (Figs 10A–B). Karyotypes (Figs 5b–c). Two different karyotypes were observed but the relationship between the karyotypes and subraces mentioned above is yet unknown.

FIGURES 15A–G. Leiobunum hiraiwai, penis, ventral (left) and lateral view (right), Western Kantô race. Localities: A. Togakushi-Chûsha (50). B. Kurumasaka Pass (51). C. Mt Haruna (52). D. Mt Hiuchi (53). E. Yumoto Spa (54). F. Nippara (56). G. Mt Bushu-Mitake (57). Numerals in parentheses denote code numbers of localities given in Fig. 7.

(1) Karyotype in Mt Bunagatake in the Hira Mountains (Shiga Pref.). (Population No. 10 in Table 1 and Fig. 7). 2n%= 20. The autosomes consist of 9 pairs of submetacentric or metacentrics. The X chromosome is submetacentric in structure and similar in size to chromosomes 2 or 3, while the Y is the smallest and metacentric. A typical example of pericentric inversion polymorphism was detected in chromosome 3. This chromosome pair is submetacentric, having an arm ratio of r = 2.0. However, in one male specimen this chromosome pair seems to be heterozygous for a pericentric inversion, because the arm

174 © 2006 Magnolia Press TSURUSAKI ratio is r = 5.0 in one homolog but r = 2.0 in the other (Fig. 5b). ZOOTAXA (2) Karyotype in the Tsuetsuki-tôge pass (Nagano Pref.). (Population No. 22 in Table 1 1325 and Fig. 7). 2n (%) = 20. The autosomes are composed of 4 pairs of relatively large metacentrics or submetacentrics and 5 pairs of relatively small submetacentrics or subtelocentrics. Difference of size among each autosome is small. The X is the largest chromosome and submetacentric, having an arm ratio of r = 2.0. The Y chromosome is the smallest and metacentric or submetacentric (Fig. 5c).

FIGURE 16. Summary of geographic variation in penis morphology of Leiobunum hiraiwai. Localities: 1. Mt Ariake, Is. Tsushima. 2. Mt Hiko. 3. Mt Azuma. 4. Mt Bunagadake. 5. Mt Hakusan. 6. Kôzenji Temple, Komagane. 7. Kamikôchi. 8. Lake Kawaguchi. 9. Mt Amagi, Izu. 10. Umegashima Spa. 11. Kowashimizu, Mt Kirigamine (Kowashimizu population). 12. Mt Bushû- Mitake, Tokyo. 13. Yumoto Spa, Nikko. Populations circumscribed by the same enclosure represents a race. Arrow head denotes barbs on the alate part of the penis.

Distribution. Eastern part of the Chugoku district (Tottori and Okayama Prefectures), Kinki district, and southwestern areas of the Chûbu district (Fig. 7).

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 175 ZOOTAXA Biology. This race was found to be sympatric with a thelytokous species, L. 1325 manubriatum Karsch, 1881 (population including males), in a planted Japanese Larch and Betula platyphylli woodland at Mt Hakkaisan (1650–1670 m alt.), halfway up of Mt Ontake. In that woodland specimens of the Kinki race were found mainly on trunks of trees, while almost all individuals of L. manubriatum were found on leaves of bamboo grass that is predominant in the undergrowth. This race is also sympatric with Leiobunum montanum on the northwestern slope of Mt Hyônosen. More details of the co-occurrence of both species in the area will be reported elsewhere.

(4) Kamikôchi race (Figs 2H–I, 3D, 6a, 12A–D)

Liobunum hiraiwai: Suzuki 1953: 181, figs 4A–D, F–I, 5A–C. Leiobunum hiraiwai fuji: Suzuki 1976: 241, figs 57–58, 116, 279.

Diagnosis. This race is clearly distinguishable from the Kinki race by size and shape of the penis (compare Figs 12A–D and 9–12, 11A–D). In the general appearance of the penis, this race is similar to the Fuji race but distinguishable from it by a pair of trifurcate barbs on the posterior margins of the distal penial winglets. Karyotype (Fig. 6a). 2n(%) = 20 (population Nos 26–29 in Table 1 and Fig. 7). The karyotype obtained from Ariake Spa specimens is described as follows. Autosomes are composed of 3 pairs of submetacentrics (chromosome 1, 5, 9) and 6 pairs of metacentrics. The X is submetacentric with a secondary constriction on the long arm, and similar in size to chromosome I. The Y is the smallest metacentric or submetacentric. Distribution. Western mountainous areas of Nagano Prefecture (outskirts of the Hida Mountain Range and Mt Norikura). Further extensive surveys will probably reveal that the distributions of this race and the Kinki race are parapatric, although the closest distance for known records of both races is only about 11 km (between the Sakai-tôge Pass and Narai) (see Fig. 7). Biology. This race was found together with L. manubriatum (all-female population) in two localities (Suzuran, Mt Norikura; and Nakabusa Spa, foot of Mt Tsubakuro). On Mt Tsubakuro this race inhabits mainly Japanese Larch forests in lower altitudes (from ca. 1400 up to 2000 m alt.), and seems to be replaced by L. montanum (Mt Tsubakuro race) in subalpine coniferous forests (above 2000 m alt.) (see Tsurusaki 1985b). Adults seem to appear in early July in Kamikôchi (ca. 1500 m in alt.).

Liobunum hiraiwai: Suzuki 1953: 181, figs 4J, 5G–H; Tsurusaki & Ikeda 1987: 6, figs 4A–B, 5C–H. Leiobunum hiraiwai fuji Suzuki, 1976: 241, figs 53–56, 113–114, 277–278, 351–352.

Diagnosis. Distinguishable from the Kamikôchi race by its enlarged penis and by differences in the shape of the postlateral barbs of the distal penial winglets. It is also distinguishable from the Izu race by the shape of the penis, especially of its distal winglets. Karyotype. 2n(%) = 20 (Lake Kawaguchi; population No. 46). As chromosome slides were made by squash method alone, no good spreads of spermatogonial metaphase could be obtained. Therefore the exact structure of each chromosome is still uncertain.

2n(%) = 22 (Mt Kiyosumi, Bôso Peninsula, Chiba Pref.). Details of this karyotype are reported elsewhere, together with data recently obtained for numerous other localities. Distribution. Outskirts of Mt Fuji, Tanzawa Mountains, and Mt Kiyosumi (Bôso Peninsula) (Shizuoka, Yamanashi, Kanagawa and Chiba Prefectures). The distribution range of this race almost meets with that of the Izu race in a fairly narrow area in the vicinities of Mt Hakone. the closest distance of known records between the two races is 3 km (see Fig. 7; also see Tsurusaki & Ikeda 1987). Biology: This race mainly inhabits woodlands of Japanese Red Cedar or Japanese Larch.

(6) Izu race (Figs 1D, K; 2L–M; 3I, 6e; 13A–C)

Leiobunum hiraiwai izuense Suzuki, 1976: 239, figs 51–52, 112, 256–257, 270–274, 348–350. Leiobunum hiraiwai fuji: Suzuki 1976: 241, fig. 278. Leiobunum hiraiwai: Tsurusaki & Ikeda 1987: 6, figs 5A–B.

Diagnosis. Unlike the Fuji race, males of the Izu race have elongated distolateral swellings on their penis shaft (Figs 13A–C). Moreover, this race has a bright-colored palp (Fig. 3I). Except for a slightly different distal swelling of the penis and a larger body size, this race corresponds to the Kyushu-Hiroshima race in some characters (e.g., light-colored palps, elongated and slender male labrum, general appearance of penis). However, these two races differ in the number of chromosomes (Izu race: 2n = 22, Kyushu-Hiroshima race: 2n = 18). Karyotype (Fig. 6e). 2n(%) = 22 (Mt Amagi; population No. 40 in Table 1 and Fig. 7). The autosomes are composed of 1 pair of large-sized submetacentrics, 6 pairs of medium- sized metacentrics or submetacentrics (3: metacentrics / 3: submetacentrics), and 3 pairs of

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 177 ZOOTAXA small metacentrics. The X chromosome is metacentric, similar in size to chromosome 1, 1325 and the Y is the smallest metacentric. Distribution. Izu Peninsula (Shizuoka Pref.) and the southern areas of Hakone (Kanagawa Pref.) (Fig. 7).

(7) Utsukushigahara race (Figs 1B, J; 2N–O; 3F; 6b–c; 13D–G, 14)

Leiobunum tsushimense: Suzuki 1976: 234, figs 66, 245–246, 250–251, 342–343. Leiobunum hiraiwai shiranense Suzuki, 1976: 244, figs 59–60, 116, 255, 275–276.

Diagnosis. Distinguishable from the two adjacent races, Kinki and Fuji, by its shorter penis and by the shape of the distal penial winglets (Figs 13D–G, 14). This race can be separated from the Western Kantô race by the slightly different distal winglets of the penis; namely in the Utsukushigahara race the anterior membranous swelling of the alate part somewhat expands toward both lateral sides, while in the Western Kantô race it never projects laterally. The shape of the distal winglets of the penis is quite variable from locality to locality. Some populations only contain individuals having a typical “tsushimense penis”, while in other populations only typical “hiraiwai penis” have been encountered. Moreover, some populations contain males of these two types and their intermediates. For example, 48 males collected from two populations (1630 m and 1660 m in alt., respectively) in Kowashimizu (Nos 44–45, in Fig. 7), located on the slopes of Mt Kirigamine, showed a great variety in the shape of their penes (Figs 14B–D). Some had a typical “tsushimense penis” (Fig. 14D), some a typical “hiraiwai penis” (Fig. 14B) and others showed all gradations between the two extreme types (Fig. 14C). The male holotype (Fig. 13F) of L. h. shiranense from Mt Shirane-sanzan having vestigial barbs on its penial winglet suggests that similar situations exist in some populations of the Southern Japanese Alps (= Akaishi Mountains). The distributional range of this race might be, as a whole, best interpreted as a wide transitional zone between southwestern Kinki race and northeastern Western Kantô race (see Fig. 7). Karyotype (Figs 6b–c). 2n(%) = 20 (population Nos 42, 44, 45 in Table 1 and Fig. 7). The autosomes are composed of 8 pairs of metacentrics or submetacentrics and l pair of subtelocentrics (chromosome 6). The X chromosome is the largest submetacentric, while the Y is submetacentric or subtelocentric in structure and similar in size to chromosome 7 or 8. Distribution. Outskirts of Mt Utsukushigahara, Mt Kirigamine (Nagano Pref.) and the Akaishi Mountains (Yamanashi and Shizuoka Prefectures). The southernmost record is Umegashima Spa in Shizuoka Pref.

Liobunum tamanum Suzuki, 1957: 113, figs 1–3, 5–8, 16, 19, 22, 24–25. Leiobunum tamanum: Suzuki 1976: 232, figs 72–73, 124, 239–244, 340–341; Tsurusaki & Hayashi 1985: 509. Leiobunum hiraiwai: Tsurusaki 2002b: 92; 2005: 810.

Diagnosis. Distinguishable from the Utsukushigahara race in lacking a membranous swelling at the neck of the penis. In addition, this race may be characterized by having a spindle-shaped glans. The penis is quite variable from locality to locality in this race, but without any cline or distinct geographic trend. Karyotype. Two karyotypes having different chromosome numbers were observed. (1) Karyotype in Mt Bushû-Mitake population (No. 57 in Table 1) (Fig. 6d). As unfortunately only very few unsatisfactory chromosome spreads could be obtained, the following description should be regarded as tentative. 2n(%) = 22. The autosomes consist of 8 pairs of metacentrics or submetacentrics and 2 pairs of submetacentrics or subtelocentrics. The X and Y sex chromosomes can be identified as the largest submetacentric and the smallest metacentrics or submetacentric, respectively. (2) Karyotype in Togakushi population (No. 50 in Table 1). 2n = 20. First metaphase of spermatocyte showed always 10 bivalents. However, since satisfactory spreads of spermatogonial metaphase could not be obtained, further karyotypic analyses could not be done. Distribution. Northern part of Nagano Pref. and northwestern mountainous areas of Kantô District (Fig. 7). Biology: This race is sympatric with a thelytokous species, L. manubriatum (populations accompanied by males) at least at two localities (Togakushi-Kôgen and Mt Hiuchi-ga-take). In the Japanese Larch forest of Togakushi-Kôgen most specimens of this race were found on trunks of trees, whereas L. manubriatum was mainly collected from undergrowth consisting primarily of bamboo grass. On the other hand, this race seems to compete with L. curvipalpe. Namely, except for one locality (Haruna-jinja, on Mt Haruna), known records of both species are mutually exclusive, though the distributional ranges of these two species widely overlap in the Chûbu District (Fig. 17). In general, this race is found in higher altitudes than L. curvipalpe.

(9) Intermediate populations

Specimens from the following populations could not be assigned to any particular races.

(1) Mt Nyûgasa-yama population (No. 58 in Fig. 7) (Figs 5e, 11F). The penes of the specimens taken from this population possess characteristics of both

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 179 ZOOTAXA the Kamikôchi race and the Utuskushigahara race in having a typical “hiraiwai penis”. 1325 However, judging from the geographical position of this population it seems to be unnatural to consider these specimens as hybrids between the Kamikôchi and Utsukushigahara races. Therefore I hesitate to assign this population to any race in the present paper. Karyotype (Fig. 5e). 2n(%) = 20 (population No. 58 in Table 1). The autosomes are composed of 3 pairs of relatively large metacentrics or submetacentrics, 5 pairs of medium-sized metacentrics or submetacentris, and 1 pair of metacentrics. The X chromosome is the largest submetacentric, while the Y is submetacentric similar in size to chromosome 6.

(2) Todai population (No. 59 in Fig. 7) (Figs 5d, 11E). In the shape of the penis, specimens from this population show a condition intermediate between those of the adjacent Kinki race populations and those of Mt Nyûgasa-yama (Fig. 11E). This suggests the occurrence of gene introgression between both populations. However, because of the paucity of available information it is difficult to make assumptions about the relationship among them. Karyotype (Fig. 5d). 2n(%) = 20 (population No. 59 in Table 1). The autosomes are composed of 9 pairs of metacentrics or submetacentrics. The X chromosome is the largest submetacentric, while the Y is the smallest submetacentric or metacentric. The size and structure of both sex chromosomes are much more similar with those of the Tsuetsuki-tôge Pass population (Kinki race) (Fig. 5c) than with the Mt Nyûgasa-yama population.

Specimens examined

(1) Tsushima race. NAGASAKI PREF.: Is. Tsushima, Mt Ariake, 1%, 7. July 1972, S. Suzuki (ZLHU). (2) Kyushu-Hiroshima race. FUKUOKA PREF.: Mt Hikosan: 700–1190 m, 7%4& (5% Chrom. Obs.), 30. July 1982, NT; 790–900 m, 10%4&(1%Chrom. Obs.), 31. July 1982, NT. - YAMAGUCHI PREF.: Tsuno-gun, Kano-cho: Komine Pass, Cj, 710 m, 21. July 1990, 2% (1% CH), NT; Mt Nagano, Fc, Quercus cuspidate and Pieris japonica, 980 m, 21. July 1990, 3% (2%CH), NT. Kuga-gun, Nishiki-cho, Mt, Rakan, Cj, 880 m, 18. July 1990, 2% (All CH), NT. - HIROSHIMA PREF.: Yoshiwa-mura: 3%23. September 1981, M. Kuya (SC); Mominoki Forest Park, 910 m, 18. July 1990, 5%(2&CH), NT; Kanmuri-kôgen, Cj, 810 m, 18. July 1990, 3%1&(2%CH), NT. Yamagata-gun, Geihoku-cho: Mt Garyû, Quercus cuspidate, 870 m, 19. July 1990, 1&, NT; Mt Tengu-ishi, Miyama, Cj, 760 m, 4. August 1990, 6%1&, NT. Yamagata-gun, Togôchi-cho: Mt Osorakan, Furuyashiki, Cj, 740 m, 19. July 1990, 2%1&(1%CH), NT; Uchiguro Pass, Cj, 980 m, 19. July 1990, 3%2&(2%CH), NT. Sandankyô, near Hûrin-Kan, 4%1&12. August 1956, S. Suzuki (SC). Shiraki-chô, Mt Shiraki, 2 juv., 20. June 1976, NT. Hiba-gun, Takano-cho: Ônuki Pass, Cj,

180 © 2006 Magnolia Press TSURUSAKI 630 m, 6. August 1990, 1%1&, NT; Kusan-dawa Pass (SW of Mt Ôyorogi), ZOOTAXA Chamaecyparis obtusa, 770 m, 6. August 1990, 1&, NT; Tawara-goe Pass, Cj – 1325 Chamaecyparis obtusa, 800 m, 6. August 1990, 1%, NT. Hiba-gun, Saijô-cho: Rokunohara, 850 m, Hiroshima-Kenmin-no-mori, 4%3&, 8. August 1986, M. Kuya; Mt Azuma, 2%8&, 12–15. July 1974, NT; Mt Tate-eboshi, Cj, 780 m, 14. July 1989, 1&, NT. - SHIMANE PREF.: Mt Sanbe, 28. May 2000, 1 juv., H. Ishikawa. Nita-gun, Yokota-cho, valley between Ô-toge Pass and Daizenbara, (along R. Ômaki , northern slope of Mt Azuma), 7. June 1997, 1 juv., Y. Notsu. - TOTTORI PREF.: Mt Sentsû, Kinmeisui route, 12%(2%CH), 4. September 2000, NT, T. Adachi, K. Kishimoto, & M. Kawasaki. (3) Kinki Race. OKAYAMA PREF.: Anagatawa Pass, Mt Mihira, 740 m, Cj, 9%2&, 27. July 2000, NT, T. Adachi, & K. Kishimoto. Maniwa-gun, Shinjô-son: Notoro Pass, Cj, 720 m, 15%(3%CH), 30. July 1989, NT. Tanami Campground, Cj, 720 m, 19%(4%CH), 27. July 1990, NT; Doyô Dam, 680 m, 5%1&(2%CH), 27. July 1990, NT. - TOTTORI PREF.: Kôfu-cho, Mt Kenashi: 810–1000 m, 2%, 13. July 1999, NT. Yazu-gun, Wakasa-cho, Ochiori, 580 m, 25. July 1989, 1&, NT. Mt Hyônosen: 14%6&, 7. August 1977, S. Suzuki, M. Kunimoto, H. Komatsu, & NT (SC); Chûgoku Nature Trails, Cj, 960 m, 23. August 2000, 11%, K. Kishimoto; Hyônosen Skiing Ground, Cj, 900 m, 10. August 2000, 11%, K. Kishimoto - HYOGO PREF.: Shisô-gun, Haga-cho, Tokura Pass (Route 29): Cj, 750 m, 25. July 1989, 3%(2%CH); east of eastern entrance of Tokura Tunnel, 760 m, 12. August 1987, 3%. Haga-cho, Hori (Right Bank), Cj, 800 m, 10. August 2000. 11%, K. Kishimoto, 11%, NT. Mikata-gun, Muraoka-cho: Hachikita-kôgen, ca. 680 m, 17. September 1988, 1%, NT; Tsukuriyama, Cj, 580 m, 20. July 1989, 3%(2%CH), NT. - KYOTO PREF.: Funai-gun, Wachi-cho, Hodozu, Gongendani (Mt Choja-ga-dake), Cj, 330 m, 1. August 1991, 2%2&(1%CH), NT. Kitakuwata-gun, Miyama-mura, Ashû, Sugo, Cj, 370 m, 31. July 1991, 1%3& (1% CH), NT. - SHIGA PREF.: Mt Bunagatake, in Hira Mountains, 920–1120 m, 13%2& (6% Chrom. Obs.), 13. August 1982, NT. Mt Ibuki, 1250–1370 m, 5%, 30. August 1981, NT. - MIE PREF.: Mt Gozaisho-dake, 620–1140 m, 17%1&, 24. August 1981, NT. Mie-gun, Komono-cho: Mt Gozaisho-dake, Toriido Valley Campground, Cj, 360 m, 22. August 1991, 1%4&, NT. Asa-ake Valley (right bank), Pinus densiflora - Quercus cuspidata forest, 460 m, 22. August 1991, 3%7&, NT. - FUKUI PREF.: Ohno-gun, Izumi- mura: Asahi, 30. July 1989) 1%, H. Sasaji. Ohno City: L. Karikomi-ike19. August 1990, 3%1&, H. Sasaji; Mt Kyogadake, 20. August 1988, 1&, H. Sasaji; Rokuroshi, 4. August 1990, 1%, H. Sasaji. - ISHIKAWA PREF.: Ishikawa-gun, Shiramine-mura: Dônomori, along Route 157, Cj, 530 m, 24. July 1993, 1%, T. Tanabe; Shiramine, Ori-no-Shiryôkan Museum, Cj, 500 m, 22. August 1994, 1&, NT. Mt Hakusan: Chûgû Spa, in beech forest, 1060–1180 m, 9%, 29. July 1980, NT; Bettô Route, 1300–1500 m, 21. July 1994, 3&, I. Togashi; Iwama Route, 850–1300 m, 31. July 1994, 1%, I. Togashi - TOYAMA PREF.: Kami-Niikawa-gun, Ooyama-cho, Higashidani, Sumidani, 29. September 1993, 1%, N. Nunomura. - GIFU PREF.: Motosu-gun, Neo-mura, Nittô, along R157, 10. August 1987, 1%, T. Tanabe. Miya-mura, Yuya, Miya-Kiyomi Forest Road, Kayano, 20. August 2000,

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 181 ZOOTAXA 1&, Y. Takai. Nakatsugawa-shi, Mt Hoko-yama, 900–969 m, 13%1&, 14. August 1982, 1325 NT. - NAGANO PREF.: Mt Ontake, Hakkaisan, 1650–1670 m, 21%10& (2% Chrom. Obs.), 29/30. July 1981, NT. Kiso-Fukushima, Kôzen-ji, 800–850 m, 1%4&, 1. August 1980, NT. Kisokama-kôgen, Ôhara, 1050–1100 m, 1%3&, 1. August 1980, NT. Kiso-gun, Narai, Shizume-jinja, 960–980 m, 19%3&, 31. July 1981, NT. Iida-shi, Mt Kokuzô-yama, 7%4&, 18. August 1981, NT. Komagane-shi, Kôzen-ji Temple, 840–860 m, 38%2&, 18. August 1981, NT. Kami-ina-gun, Takatô, Hokomochi Shrine, 800 m, 3%2&, 17. August 1981, NT. Chino-shi, Tsuetsuki-tôge Pass: 1200 m, in Japanese Larch forest, 70%6&, 17. August 1981, NT; 1180 m, near a bus stop, 7% (2% Chrom. Obs.), 20. August 1982, NT. Mt Kirigamine, Ikenokurumi, 1550–1560 m, 4%, 22. August 1982, NT. (4) Kamikôchi race. NAGANO PREF.: Minamiazumi-gun, Nagawa-mura, Sakai Pass, 1430 m, 13%2&, 29. July 1981, NT. Minamiazumi-gun, Azumi-mura, Norikura- kôgen, Suzuran: ca. 1500 m, 18. July 1977, H. Komatsu and NT (SC); 1570 m, 7. July 1988, 5%1 juv. (1 juv.&CH), NT. Minamiazumi-gun, Azumi-mura, Norikura-kôgen, Miyanohara, Miyanohara Shrine (near Bansho), 1200 m, 7. July 1988, 2 juv.(%&CH), NT. Kamikôchi: Konashidaira, 84%6& (8% Chrom. Obs.), 28/29. July 1981, NT; from Myôjin to Tokugô-tôge Pass, 10%3&, 28. July 1981, NT; Tokusawa-en to Konashi-daira, 20%4&, 27/28. July 1981, NT; Yokoo Hütte, 1%1&, 21/22. August 1958, M. Makihara (SC); same locality, 1600–1700 m, 10%6&1 juv. (6% Chrom. Obs.), 27. July 1981, NT. Kamikôchi, 3. August 1990, 2%6&, W. Miyata. Minamiazumi-gun, Ariake Spa; 1390–1450 m, 5%1&, 19. August 1981, NT; 1400–1600 m, 4%2& (4% Chrom. Obs.), 17. August 1982, NT. Nakabusa Spa, 1400–1460 m, 6%2&, 19. August 1981, NT. Mt Tsubakuro (Nakabusa Spa to Mt Tsubakuro): 1600–2000 m, 5%3&, 20. August 1981, NT; 1500–2000 m, 3&, 18. August 1982, NT. Ohmachi-shi, Kuzu Spa, 960 m, 6. July 1988, 1%2juv.(%+&CH), NT. Higashichikuma-gun, Sakakita, unknown date in 1983, 3%1&, T. Yoshida. Chikuma-gun, Shiga-mura, Mabune, Larix kaempferi, 830 m, 4. July 1988, 1&(CH), NT. Kita-Azumi- gun: Matsukawa-mura, 30. August 1987, 3%, T. Yoshida; Odari-mura, Ishizaka, 600 m, 5. September 1992, 1&, W. Miyata. (5) Fuji race. YAMANASHI PREF.: Lake Kawaguchi, 860–880 m, Cj, 94%3& (6% Chrom. Obs.), 2. August 1981, NT. Fuji-Yoshida-shi: Karinoana Cave, Pinus densiflora, 20. August 2001, 1&, R. Ito; 1. August 1980, 1%1&, A. Matsumoto. Minami-Tsuru-gun: Narusawa-mura, Aokigahara, Chamaecyparis obtusa, 1060 m, 18. April 2002, 1 juv., R. Ito; Ashiwada-mura, L. Saiko, Neba, 910 m, 21. September 1995, 1&, NT. Mt Fuji, 3 gôme (Shôjin-guchi route), 1700–1720 m, 1&, 2. August 1981, NT. - KANAGAWA PREF.: Yabitsu-tôge Pass to Fudakake, Tanzawa Mountains, 2%4&, 9. September 1973, M. Tabuchi (SC). Isehara-shi, Mt Ohyama, Shimosha Shrine, Cj, 760 m, 25. August 1986, 24%5&(5%CH), NT. Odawara-shi, Hisano, Warusawa, 500 m, 2. August 1981, 1%, M. Ohrui. Ashigara-shimo-gun, Hakone-cho: Yakurazawa Pass, 850 m, 18. July 1997, 1%, M. Ohrui; Mt Kintoki, 1200 m, 23. July 1993, 1%2&, M. Ohrui: Kintoki Shrine: 800 m, 15. September 1984, 2%1&, M. Ohrui; 700–720 m, 19. September 1995, 2%(CH), NT. Mt

182 © 2006 Magnolia Press TSURUSAKI Sôunzan, 784 m, 29. August 1986, 1%1&, H. Ikeda. Ôwakudani: 1030 m, 14. July 1985, ZOOTAXA 1%, T. Ishihara; 1. August 1986, 3%, H. Ikeda; 15. August 1986, 1%, H. Ikeda et al.; 1000 1325 m, 19. September 1995, 2%(1%CH), NT. Hakone-cho, Sengoku-bara, 1245 m, 9. September 1986, 2%, N. Agatsuma; Mt Asama, 800 m, 21. September 1994, 2%, M. Ohrui; Hakone-en, entrance of picnic garden, Chamaecyparis obtusa, 840 m, 19. September 1995, 1%(CH), NT. - SHIZUOKA PREF.: Suntô-gun, Oyama-cho, Fuji-Reien, 750 m, 14. August 1994, 3%, M. Ohrui. - CHIBA PREF.: Mt Kiyosumi: near Kiyosumi-ji Temple, 300–320 m, 49%1& (8% Chrom. Obs.), 27. August 1984, NT; 320–340 m, Cj, 4% (2% Chrom. Obs.), 26. August 1996, NT. (6) Izu race. KANAGAWA PREF.: Ashigara-Shimo-gun, Hakone-cho: Mt Takanosu- yama, 837 m, 5%1&, 15. August 1973, M. Tashiro (SC); Suginamiki, 740 m, 1&, 8. October 1980, NT; near L. Otamaga-ike, Cj, 800 m, 3. October 1994, 2%, M. Ohrui; South of Mt Asama, 770 m, 21. September 1994, 1%, M. Ohrui; summit of Mt Takanosu, 800 m, 21. September 1994, 1%, M. Ohrui; Mt Byôbu, 900 m, 19. September 1994, 1%, M. Ohrui; east of Mt Byôbu, 850 m, 19. September 1994, 1%, M. Ohrui; Hakone Elementary School, 6. September 1986, 1%, M. Hashida et al. - SHIZUOKA PREF.: Mishima-shi, Yamanaka- Shinden, remains of Yamanaka Castle, 550 m, 19. September 1995, 1&, NT. Tagata-gun, Kan-nan-cho, Jikkoku-tôge Memorial Forest, (2.3 km N of the Jikkoku Pass), 780 m, Chamaecyparis obtusa, 22. September 1995, 1%(CH), NT. Atami-shi, Tôkôji Temple, Pieris japonica, 700 m, 10. August 1992, 1&, M. Ohrui. Izu: Kamo-gun, Higashi-Izu-cho, Mt Tôgasa, Pieris japonica forest. 1100 m, 1juv. 20. May 1993, M. Ohrui. Mt Amagi (Mt Manjirô-dake to Mt Manzaburô-dake), 1040–1400 m, 1%, 6. October 1980, NT; Mt Amagi, Amagi-kôgen Golf Course, 1040–1070 m, 21%6& (6% Chrom. Obs.), 24. July 1982, NT; Tagata-gun, Amagi-Yugashima-cho, Amagi, summit of Mt Manzaburô, 1405 m, 2. June 1995, 4 juv., M. Ohrui. Amagi Pass (from Amagi-tôge to Hacchô-ike), 720–1200 m, 1%, 5. October 1980, NT. Yugashima-cho, Himuro-enchi, 700 m: 5. July 1991, 1%, M. Ohrui, 14. July 1992, 1&, M. Ohrui; 25. August 1992, 1%, M. Ohrui; 28. July 1993, 1&, M. Ohrui; 11. August 1993, 1%1&, M. Ohrui. Tagata-gun, Yugashima-cho: Mukai Pass, 900 m, 25. July 1994, 2%1&, M. Ohrui, north of Amagi Pass, 700 m, 1992-8-11, 1&, M. Ohrui; Takigasawa, 900 m, 6. July 1994, 1%, M. Ohrui. Tagata-gun, Nakaizu-cho, R. Kobisawara, 700 m, 29. August 1995, 6%, M. Ohrui. (7) Utsukushigahara race. SHIZUOKA PREF.: Shizuoka-shi, Umegashima Spa, 900–1050 m, 88%9&, 1. September 1981, NT. - YAMANASHI PREF.: Minami-Koma- gun, Minobu-cho, Mt Minobu, 20. July 1990, 1%, H. Saito. Higashi-Yamanashi-gun, Mitomi-mura, Nishizawa Valley, 26. August 1990, 1&, H. Saito. Nakakoma-gun: Shirane- sanzan (from Mt Aino-dake to Mt Nôtori-dake), 1%1&, 27. August 1953, Z. Ôshimo (ZLHU); Mt Kita-dake, from Hirogawara to Miike, 1530–2000 m, 10%4&, 5. August 1980, NT; Hirogawara, near Hirogawara Lodge, 1520–1540 m, coniferous forests, 32%5&, 4. August 1980, NT; same locality, 1520 m, 15%, 15. August 1981, NT; left bank of Ôkanba-sawa, Mt Kitadake, 1620 m, 4. August 1987, 1%, A. Ohtaka. Ashiyasu-mura,

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 183 ZOOTAXA Yashajin-tôge Pass, 1400–1770 m, 100%20& (5% Chrom. Obs.), 6. August 1980, NT. - 1325 NAGANO PREF.: Mt Kirigamine: Kowashimizu, campground, 1630 m, Japanese Larch forest, 17%1&, 1. August 1981, NT; same locality, 22 juv. (9 juv. Chrom. Obs.), 8. July 1982, NT; 1660 m, in Japanese Larch forest, 31%4& (3% Chrom. Obs.), 19. August 1982, NT. Mt Utsukushigahara: Tobira-tôge Pass, 1700 m, 3%1&, 19. August 1982, NT; Yamamoto Hütte, 1880–1900 m, 62%10& (6% Chrom. Obs.), 19. August 1982, NT. (8) Western Kantô race. NAGANO PREF.: Togakushi-kôgen: Chûsha, 1200–1240 m, 18%5& (7% Chrom. Obs.), 23. July 1980, NT; Koshimizugahara, 1220–1230 m, 16%, 24. July 1980, NT; Bokujô, 1180–1190 m, 1%, 24. July 1980, NT. Komoro-shi, Kurumasaka-tôge Pass, 1980 m, 98%5&, 24. August 1982, NT. Miami-Saku-gun, Koumi- cho, Mt Kita-Yatsugadake, L. Shirokoma-no-ike, 2110 m, 20. September 1987, 15%1&, A. Ohtaka. - GUMMA PREF.: Matsuida-cho, Mt Kirizumi, Fagus japonica, 1000 m, 30. August 1983, 2%, K. Ishii. Usui-gun, Usui Pass (Kyûdô), 1000 m, 1. July 1984, 2 juv., T. Hayashi. Mt Haruna, Haruna-jinja, 860–900 m, 5%2&, 26. August 1982, NT. Tone-gun, Oze: Oze-numa, Chôzô Hütte Campground, 27. August 1986, 1&, A. Ohtaka; Hatomachi Pass, 12. June 1986, 2 juv., A. Ohtaka; from Sanpei Pass to Sanpei-Shita, along a board walk, 25. September 1986, 1%1&, A. Ohtaka; L. Ozenuma, Tôden Hütte (Sanpei-Shita), 20. August 1986, 2%1&, A. Ohtaka. - TOCHIGI PREF.: Nikkô, Yumoto Spa: 1500 m, 28%13&, 25. July 1981, NT; 1%, 23. July 1984, H. Saito - FUKUSHIMA PREF.: Mt Hiuchi-ga-take (Miike to Mt Hiuchi-ga-take), 1500–2320 m, 30%13&, 3. September 1980, NT. - SAITAMA PREF.: Chichibu Experimental Forest of the University of Tokyo, 26. July 1998, 1%1&, M. Imai, Ôtaki-mura. Mitsumine Shrine, 25. July 1998, 1%, M. Imai, Chichibu-gun, Ogano-cho, southern slope of Mt Futago (Climbing route from the Shigasaka Pass), ca. 750 m, 15. September 1986, 1&, A. Ohtaka. - TOKYO PREF.: Nishitama-gun, Okutama-cho: Nippara, 1%, 1. August 1965, J. Aoki (SC); Minebata, Experimental Forest of Tokyo University of Agriculture, 710 m, 4. July 1997, 1&, Rihoko Negishi. Oume-shi, Mt Mitake (= Mt Bushû-Mitake): 820–860 m, Cj, 112%25&, 7. August 1980, NT; same locality, 820–850 m, 9%7& (7% Chrom. Obs.), 23. July 1982, NT. (9) Intermediate populations. NAGANO PREF.: Suwa-gun, Mt Nyûgasa-yama, 1470–1900 m, 41%5& (5% Chrom. Obs.), 21. August 1982, NT. Kami-Ina-gun, Todai, 1000–1020 m, 2%2& (1%Chrom. Obs.), 20. August 1982, NT.

Measurements

Lengths of body and legs also vary considerably among populations. It seems that some races are larger than the others (e.g., populations belonging to the Kinki race seem to have larger bodies). However, their patterns of variation are rather complicated because they also vary with increase of altitude or latitude of the populations. Geographical patterns of variation in the body size in L. hiraiwai will be dealt in a separate article. Only measurements of males from five different populations are given here:

184 © 2006 Magnolia Press TSURUSAKI Kyushu-Hiroshima race: Rokunohara, 850 m, Hiroshima-Kenmin-no-mori, Hiroshima ZOOTAXA Pref. (n = 4, mean in parentheses): BL 4.0–4.8 (4.37), PrL 1.23–1.45 (1.34), FIL 6.3–6.6 1325 (6.46), PaL 4.61–4.99 (4.75). Kinki race: Notoro Pass, 720 m, Shinjo-son, Okayama Pref. (n = 12, mean±SD in parentheses): BL 4.0–5.1 (4.74±0.35), PrL 1.23–1.58 (1.43±0.13), FIL 5.6–6.8 (6.17±1.82), PaL 4.97–5.50 (5.25±0.05). Utsukushigahara race: Yashajin tôge Pass, 1400–1600 m, Yamanashi Pref. (n = 10, mean±SD in parentheses): BL 3.3–4.5 (4.10±0.43), PrL 1.07–1.28 (1.17±0.09), FIL 6.1–8.2 (6.9±0.65), PaL 3.92–4.40 (4.13±0.15). Western Kantô race: Togakushi-Chusha, 1200–1240 m, Nagano Pref. (n= 9, mean±SD in parentheses): BL 4.3–5.9 (5.19±0.59), PrL 1.15–169 (1.41±0.22), FIL 6.1–7.1 (6.73±0.32), PaL 4.21–4.73 (4.50±0.16). Western Kantô race: Mt Bushû-Mitake, 820–860 m, Tokyo Pref. (n = 10, mean±SD in parentheses): BL 3.7–4.6 (4.16±0.26), PrL 1.0–1.34 (1.11±0.11), FIL 6.6–7.6 (7.01±0.27), PaL 3.92–4.40 (4.13±0.14).

Discussion

Closest relatives of the hiraiwai-subgroup (= L. hiraiwai) The phylogenetic relationships among the seven subgroups (hikocola, montanum, hiasai, kohyai, hiraiwai, curvipalpe, manubriatum) of the Leiobunum curvipalpe-group are not yet resolved (Tsurusaki 1985a). However, there are a few traits that may suggest that the hiraiwai-subgroup and the curvipalpe-subgroup are closest relatives. One is the resemblance in the basic structure of the penes, especially in the distal parts that possesses a pair of pouches formed by dorsal and ventral extensions of the winglets in both subgroups. Additionally, darkened palps are only shared by the hiraiwai- and curvipalpe- subgroups and can be considered as a synapomorphy of the two subgroups. This is a character that shows geographic variation, and the degree of melanism of the palps is highest in the area around the Chûbu District of central Honshu in both subgroups (Fig. 4; see fig. 4 in Tsurusaki 1990 for the curvipalpe-subgroup). This suggests that genes that control melanism originated somewhere in this area and had been present in a hiraiwai- curvipalpe ancestor before the two subgroups diverged and became reproductively isolated. It is likely that geographic differentiation in chromosome number also had been in progress before the two subgroups became fully reproductively isolated. The highest chromosome number (2n = 22) in the hiraiwai-subgroup is found in the easternmost area of its distributional range, whereas in the curvipalpe-subgroup (Fig. 17) the number reaches its maximum in the southernmost part of the distributional range (2n = 24). When these two subgroups are viewed together, the spatial pattern suggests that the highest numbers are found in the center of the distributional range of the hiraiwai-curvipalpe

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 185 ZOOTAXA clade and decreases toward southwest and northeast (Fig. 17, above). For a spatial pattern 1325 like this, the most conceivable process of differentiation is that chromosome numbers have increased gradually from the most plesiomorphic state 2n = 18 in the center of the distribution.

FIGURE 17. Distributions of the three major subgroups of the Leiobunum curvipalpe-group. Top: Outlines of distributions and diploid chromosome numbers of the hiraiwai-subgroup and the curvipalpe-subgroup. Below: Mutually exclusive distributions of the montanum-subgroup and the hiraiwai-subgroup. Dotted lines denote ranges of Japanese Beech (Fagus crenata) forest, and shaded areas subalpine coniferous forests. L. montanum is restricted to a few high altitude localities in subalpine coniferous forest, such as Abies forests, in the Hida Mountains in central Honshu. For the details on the curvipalpe-subgroup and the montanum-subgroup, see Tsurusaki (1985a, 1990).

Spatial pattern of trait differentiations in the hiraiwai-subgroup (= L. hiraiwai) This subgroup is the most variable taxon within the curvipalpe-group. The spatial patterns of two other characters suggest that derived conditions principally arose in the center of the species range of L. hiraiwai, as the stasipatric model of speciation predicts (White 1968, 1978). These characters concern penis morphology. The presumed process of geographic differentiation in these penis characters and in the labrum shape in the hiraiwai-subgroup is outlined in Fig. 18. Two postulates are adopted in the following scenario: 1) the ancestor of L. hiraiwai occupied a wide range extending from Tsushima

186 © 2006 Magnolia Press TSURUSAKI Island to Kantô District when Tsushima Island was connected with the main Islands of ZOOTAXA Japan by a land bridge (the final formation of the Tsushima strait was ca. 17,000 years 1325 B.P.; Kitamura et al. 2001), and 2) the ancestor had a non-barbed penis similar to the “tsushimense-type” that is nowadays shared by the Tsushima race and a part of the Utsukushigahara race. Stage 1: At this stage, a barbed “hiraiwai-type” penis evolved in the center of the distributional range. It can be used to differentiate the ancestral form with a “tsushimense-type” penis into two populations, namely the north-eastern and westernmost populations. Displacement of the pre-existing “tsushimense-type” by the new “hiraiwai- type” was probably achieved by the gradual movement of a narrow hybrid zone, which may have been similar to the situation now observed in some populations of the Utsukushigahara race. Stage 2: The elongated penis found today in the Kinki race had emerged in the center of the range and displaced the preceding “hiraiwai-type” penis eastward and westward. Stage 3: At this stage, recession of some populations from lowland to peaks, especially in the vast area ranging from Kyushu to Kinki District and in mountainous areas of the northern Kantô, facilitated further transformations of various characters in different populations. A unique rod-shaped labrum in males appeared in the Tsushima Island population. A slight modification of the distal part of the penis occurred in the Izu Peninsula. The present-day Western Kantô race evolved from the Utsukushigahara race, though the boundary between these two cannot be drawn with confidence because of fairly large geographic variation in male genitalia among the known populations (see Figs 14–15). Several events assumed at stage 3 may have taken place at stage 2. In any case, present-day conditions are derived from superposition of stages 2 and 3 (Fig. 7).

FIGURE 18. Diagrams illustrating the possible evolution of the races in Leiobunum hiraiwai. Details in the text.

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 187 ZOOTAXA Complementary distributions of L. hiraiwai and L. montanum 1325 Leiobunum hiraiwai is widely distributed in the western part of the Japanese Islands, from Tsushima Island to the northwestern mountainous areas of the Kantô District of Honshu. However, the range occupied by this species does not overlap with that of another widely distributed subgroup, the montanum-subgroup (= L. montanum Suzuki, 1953) (Fig. 17 below). In the Hida Mountains (Nos 25–30 in Fig. 7) and Mt Ontake (No. 17 in Fig. 7), where both species can be found, L. montanum is restricted to the subalpine coniferous forests (Abies mariesii and Abies veitchii) at more than 1700 m altitude, while L. hiraiwai occurs at lower altitudes (less than 1700 m) on those mountains, in Japanese Beech (Fagus crenata) or Japanese Larch (Larix kaempferi) forests. Both species usually do not occur sympatrically, except for a locality recently found on the northeastern slope of Mt Hyônosen of the Chugoku Mountains (Loc. No. 8 in Fig. 7; details of the co-occurrence in this area will be reported elsewhere). Such a complementary pattern of distribution, also known as “checkerboard pattern” (Diamond 1975) has been found among birds, reptiles, mammals and some insects (e.g., two polistine wasps, Polistes rothneyi and P. jokahamae, in the Ryukyu Islands; Yamane 1986). It has received attention by community ecologists as an exemplification of interspecific competition between two closely related species over the same resources (Tokeshi 1999, Lomolino et al. 2006). However, it is unlikely that the complementary distributional ranges of L. hiraiwai and L. montanum are a consequence of interspecific resource competition, because most species of harvestmen are generalists that can also voraciously consume all kinds of dead and immobilized prey (Adams 1984). Another factor that may result in mutually exclusive distributions between two closely related species is “reproductive interference”, which arises when two species lacking premating isolating mechanisms mate without producing fertile hybrids (thus, no introgression of genes) (Kuno 1992, Fujimoto et al. 1996, Takafuji 1998). Fujimoto et al. (1996) explained mutually exclusive patterns of distribution between two closely related spider mites, Panonychus citri and P. mori, by their asymmetric reproductive interference (P. m o ri is replaced by P. citri as the interference proceeds). It is likely that Leiobunum hiraiwai and L. montanum also easily copulate when they come across each other, since 1) they look alike (it is often difficult to distinguish the two species clearly in the field) and have similar body size, 2) their sense of sight seems to be not well-developed, as is the case in other harvestmen, 3) there are no complex copulation behaviors, and 4) there is no difference between the two species in their reproductive season (both species mature in early July and they copulate for one or two months after attaining maturity). Thus, the complementary distributions of Leiobunum hiraiwai and L. montanum may also be ascribed to possible reproductive interferences among them. Interestingly, at a locality on the northwestern slope of Mt Hyônosen where both species occur together, the difference in body size is enormous (L. montanum at this population has an extremely elongated body and is much larger than the sympatric L. hiraiwai). This fact also suggests that a certain extent of size difference is required for the co-occurrence of these two species.

188 © 2006 Magnolia Press TSURUSAKI Acknowledgments ZOOTAXA 1325 I thank Dr Seisho Suzuki, Prof. Emeritus of Hiroshima University for lending me many specimens from his personal collection. Cordial thanks are also due to Prof. Haruo Katakura of Hokkaido University for reading an earlier version of the manuscript. The following colleagues kindly provided specimens of L. hiraiwai: T. Yoshida, T. Tanabe, H. Ishikawa, W. Miyata, R. Ito, M. Ohrui, K. Ishii, M. Imai, H. Ikeda, H. Saito, A. Ohtaka, I. Togashi, T. Hayashi, M. Murakami-Ohnishi, K. Kishimoto. This work was funded by Grants-in-aid for Scientific Research from the Japan Society for the Promotion of Science (Nos 63740434, 02854100, 03740393, 13640696, 16570076). Special thanks go to Drs Peter J. Schwendinger and Gonzalo Giribet for their very helpful review of the manuscript and for useful comments. This paper is dedicated to Prof. Dr Jochen Martens who carved new horizons in systematics and phylogeny of harvestmen and was leading in research on Opiliones for many years.

References

Adams, J. (1984) The habitat and feeding ecology of woodland harvestmen (Opiliones) in England. Oikos, 42, 361–370. Gorlov, I.P. & Tsurusaki, N. (2000) Staggered clines in a hybrid zone between two chromosome races of the harvestman Gagrellopsis nodulifera (Arachnida: Opiliones). Evolution, 7, 157–168. Diamond, J.M. (1975) Assembly of species communities. In: Cody, M.L. & Diamond, J.M. (Eds), Ecology and evolution of communities. Belknap Press, Cambridge, 342–444. Fujimoto, H., Hiramatsu, T. & Takafuji, A. (1996) Reproductive interference between Panonychus mori Yokoyama and P. citiri (McGregor) (Acari: Tetranychidae) in peach orchards. Applied Entomology and Zoology, 31, 59–65. Key, K.H.L. (1981) Species, parapatry, and the morabine grasshoppers. Systematic Zoology, 30, 425–458. King, M. (1993) Species evolution. The role of chromosome change. Cambridge University Press, Cambridge, 336 pp. Kitamura, A., Takano, O., Takata, H., & Omote, H. (2001) Late Pliocene – early Pleistocene pale- oceanographic evolution of the Sea of Japan. Palaeogeography, Palaeoclimatology, Palaeo- ecology, 172, 81–98. Kuno, E. (1992) Competitive exclusion through reproductive interference. Researches on Popula- tion Ecology, 34, 275–284. Lomolino, M.V., Riddle, B.R. & Brown, J.H. (2006) Biogeography. 3rd ed. Sinauer Assoc., Sunder- land, Massachusetts, 845 pp. Sato, I. & Suzuki, S. (1939) Zwei neue Nelima-Arten aus Japan. Annotationes Zoologicae Japon- enses, 18, 35–41. Suzuki, S. (1953) Studies on the Japanese harvesters. VI. Some new and little known species of the genus Liobunum C. L. Koch from Japan, with special reference to the comparative study of penis. Journal of the Faculty of Science, Hiroshima University (B-1), 14, 173–200. Suzuki, S. (1957) On the three closely related forms of the genus Liobunum (Phalangiidae, Opil- iones). Journal of the Faculty of Science, Hokkaido University, VI, Zoology, 13, 109–117. Suzuki, S. (1966) Two new species of the genus Leiobunum (Leiobunidae, Opiliones) from East Asia. Annotationes Zoologicae Japonenses, 39, 160–168.

LEIOBUNUM HIRAIWAI © 2006 Magnolia Press 189 ZOOTAXA Suzuki, S. (1976) The genus Leiobunum C. L. Koch of Japan and adjacent countries (Leiobunidae, 1325 Opiliones, Arachnida). Journal of Faculty of Science, Hiroshima University (B-1), 26, 187–260. Suzuki, S. (1980) A taxonomic revision of some geographic forms of Leiobunum hiraiwai. Japa- nese Society of Systematic Zoology, Circular, 53, 13. (Abstract of the 16th Annual Meeting of Japanese Society of Systematic Zoology). [in Japanese] Suzuki, S. (1986) Opiliones of Hiroshima Prefecture (Arachnida). Hibakagaku (Journal of the Hiba Society of Natural History), 132, 7–45. [in Japanese with English summary] Takafuji, A. (1998) Biology of spider mites. Springer Verlag, Tokyo, 214 pp. [in Japanese] Tokeshi, M. (1999) Species coexistence. Ecological and evolutionary perspectives. Blackwell Sci- ence, Oxford, 454 pp. Tsurusaki, N. (1985a) Taxonomic revision of the Leiobunum curvipalpe-group (Arachnida, Opil- iones, Phalangiidae). I. hikocola-, hiasai-, kohyai-, and platypenis-subgroups. Journal of Fac- ulty of Science, Hokkaido University, VI, Zoology, 24, 1–42. Tsurusaki, N. (1985b) Geographic variation of chromosomes and external morphology in the montanum-subgroup of the Leiobunum curvipalpe-group (Arachnida, Opiliones, Phalangiidae) with special reference to its presumable process of raciation. Zoological Science, 2, 767–783. Tsurusaki, N. (1990) Taxonomic revision of the Leiobunum curvipalpe group (Arachnida, Opil- iones, Phalangiidae). III. Leiobunum curvipalpe subgroup. Japanese Journal of Entomology, 58, 761–780. Tsurusaki, N. (1993) Leiobunum montanum and L. hiraiwai. In: Ehara, S. & Tsurusaki, N. (Eds), Tottori's outstanding nature, animals and their conservation. Tottori Prefecture, Tottori, 214–215. [in Japanese] Tsurusaki, N. (2002a) Leiobunum hiraiwai. In: Tsurusaki, N. (Ed.), Threatened wildlife of Tottori Prefecture, Animals. Tottori Prefecture, Tottori, 168. [in Japanese] Tsurusaki, N. (2002b) Opiliones. In: Soil Animals Division, Research Association for Natural Envi- ronment of Tochigi Prefecture (Ed.), Soil animals of Tochigi. Department of Natural Environ- ment of Tochigi Prefecture, 505–511. [in Japanese] Tsurusaki, N. (2005) Leiobunum hiraiwai. In: Tochigi Prefectural Museum (Ed.), Red Data Book of Tochigi. Tochigi Prefecture, Utsunomiya, 810. [in Japanese] Tsurusaki, N. (in press) Methods of chromosome preparation. In: Pinto da Rocha, R., Machado, G. & Giribet, G. (Eds) Harvestmen: The biology of Opiliones. Harvard University Press, Cam- bridge, Massachusetts. Tsurusaki, N. & Hayashi, T. (1985) Opiliones of Gumma Prefecture, central Honshu. In: Gumma Prefectural Board of Senior High School Education (Ed.), Fauna of Gumma Prefecture. Gumma Prefecture, Maebashi, 505–511. [in Japanese] Tsurusaki, N. & Ikeda, H. (1987) Opiliones of the Hakone district, Japan. Report of the Owakidani Natural History Museum, Hakone, 7, 1–16. [in Japanese with English abstract] Tsurusaki, N., Murakami, M. & Shimokawa, K. (1991) Geographic variation of chromosomes in the Japanese harvestman, Gagrellopsis nodulifera, with special reference to a hybrid zone in western Honshu. Zoological Science, 8, 265–275. Tsurusaki, N. & Okada, S. (2000) IV. Animals. In: Landscape and Nature Division of Tottori Pre- fecture (Ed.), Report of the scientific surveys on natural environment of Mt. Kenashi and Mt. Hôbutsu. Landscape of Nature Division of Tottori Prefecture, 59–92. [in Japanese] Tsurusaki, N. & Sasaji, H. (1991) Opiliones of Fukui Prefecture, central Honshu, Japan. Entomo- logical Journal of Fukui, 8, 2–20. White, M.J.D. (1968) Models of speciation. Science, 159, 1065–1070. White, M.J.D. (1978) Modes of speciation. W. H. Freeman and Co., San Francisco, 455 pp. Yamane, S. (1986) Distributional patterns of Xylocopa bees and Polistes wasps in the Nansei Islands. In: Kimoto, S. (Ed.), Biogeography of insects of Japan. Tokai University Press, 43–49. [in Japanese]