Plesiochara inflexa, Inoue & Maruyama, 2022

Inoue, Shûgo & Maruyama, Munetoshi, 2022, Revision of the genus Plesiochara Sawada (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 5165 (4), pp. 501-519 : 510-513

Plesiochara inflexa sp. nov.

Japanese common name: Nise-kusabira-hanekakushi

( Figs 6A–F , 7A–D , 8 , 12D–F )

Description. Body elongate; head, thorax and abdomen dark brown; antennae dark reddish brown, with basal part paler; mouth parts and legs reddish yellow; elytra reddish yellow with posterolateral portion darker; head, thorax, abdominal sternites, elytra, and legs covered with setae rather densely; abdominal tergites sparsely covered with setae; dorsal surface of head and pronotum densely covered with reticulation; elytra weakly rugose; abdominal tergites glossy.

Head circular, slightly longer than or as long as wide; postocular parts roundly narrowed toward base; eyes ovate. Antennae slender, longer than a combination of head and pronotum; segments IV–V slightly longer than wide; segments VI–VII as long as wide; segments VIII–IX slightly transverse; segments X as long as wide; segments XI ovate.

Pronotum almost hexagonal, slightly wider than long; anterior margin widely rounded; lateral margin moderately rounded, narrowed more strongly to posterior than anterior; anterior corners rounded; posterior corners obtusely roundly angulated; hypomera visible in lateral view, with posterior part of carina ( Fig. 12D–F ) directed to posterolateral corners obliquely and curved inward at posterior end in most cases.

Mesoventrite shortly carinate at base of midline; inner coxal process narrow, elongate, reaching to metaventrite process. Metaventrite with inner coxal process short, moderately narrow.

Elytra wider than long, longer and wider than pronotum, weakly diverging to posteriorly, widest near posterolateral corners; hind margin sinuate near posterolateral corners. Hind wings developed.

Abdomen moderately elongate, parallel sided; tergites III–VII with small pores at basal impression; VIII tergite with posterior margin smooth, shallowly emarginate medially in both sexes. VIII sternum with posterior margin smooth, widely rounded in both sexes.

Legs slender, rather long (HTL/PL = 1.27–1.40); surface of fore and middle tibia not covered with spines; hind tarsal segments I longer than a combination of II and III.

Male: Median lobe of aedeagus ( Fig. 6B–E ) rather large; apical lobe rather thin, curved ventrally; sclerites 1 oblong, narrowed ventrally, curved posteriorly at ventral apex; one pair of sclerites 4 (sc4) rather distinct, located near apex of sclerites 2, strongly curved inward.

Female: Spermatheca ( Fig. 6F ) with capsule ovate, small, almost as long as chamber.

Measurements. BL 4.5–5.5, FBL 2.63–3.10, HW 0.74–0.77, HL 0.76–0.80, PW 0.93–1.07, PL 0.83–0.98, EW 1.33–1.44, EL 1.01–1.21, HTL 1.05–1.32.

Variation. Tanzawa mountains (Mt. Ishihodo-yama, Kanagawa Pref.; near Dôsaka tunnel, Yamanashi, Pref.): Hypomera with carina not curved inward at posterior end ( Fig. 12F ); legs longer; median lobe of aedeagus with apical lobe thin, rather weakly curved ventrally, narrower in ventral view ( Fig. 7A–B ). Shikoku (Mt. Tsurugi-san, Tokushima Pref.): median lobe of aedeagus with apical lobe thin, rather weakly curved ventrally, narrower in ventral view ( Fig. 7C–D ). Hypomeral carina curved weakly or not curved in eastern localities ( Fig. 12E ), curved strongly in northern localities ( Fig. 12D ).

Type materials. Holotype: male, Wakasugi forest , Nishiawakura-son, Okayama Pref., JAPAN, 22.X.2009, T. Ito leg., from mushroom ( KUM) . Paratype. JAPAN: Hokkaido: [Hokkaido Pref.]: 1 unsexed, Kiyosato-chô , 27.X.2009, K. Matsumoto leg. (cI) ; 1 unsexed, Kamimuri, Maruseppu-chô , 21. V.2000, M. Maruyama leg., from bear dung ( KUM) ; 1 unsexed, Nagahashi, Naebo, Otaru-shi , 1. V.1992, M. Ôhara leg., by bait trap ( KUM) ; 5 male, 3 female, 5 unsexed, ditto, 8.X.1992, M. Ôhara leg. By bait trap ( OM, KUM) ; 2 unsexed, ditto, 15.X.1992, M. Ôhara leg. By bait trap ( KUM) ; 3 female, 1 unsexed, ditto, 22.X.1992, M. Ôhara leg. By bait trap ( OM, KUM) ; 2 male, 2 female, 1 unsexed, ditto, 29.X.1992, M. Ôhara leg. By bait trap ( KUM) ; 1 male, ditto, 5.XI.1992, M. Ôhara leg. By bait trap ( KUM) ; 2 female, Kakkumi-chô, Hakodate-shi , 12.IV.2020, Y. Tasaku leg. ( KUM) ; Honshu : [Aomori Pref.]: 1 male, Oirase, Fukaura-chô , 9.VII.1989, A. Abe leg. ( KUM) ; [Yamagata Pref.]: 1 male, 1unsexed, Ichino-taki, Chôkai-zan, Sakata-shi , 10.X.2015, H. Ooki leg. ( KUM, cO) ; [Fukushima Pref.]: 1 male, 1 unsexed, Futamata-onsen , Ten-ei-mura, 850 m, 19.X.2003, S. Nomura leg. ( KUM) ; [Tochigi Pref.]: 1 female, Okukinu, Kuriyama-mura , 30. V.1991, S. Naomi leg. ( KUM) ; [Gunma Pref.]: 1 male, 3 unsexed, Marunuma, Katashina-mura , 23.IX.1969, Y. Shibata leg. ( KUM) ; 4 male, 1 female, Tamahara-kogen, Kamihocchi-machi, Numata-shi , 26.X.2003, N. Kanai leg. ( KUM) ; 2 unsexed, Aratosawa, Mt. Hotaka-san, Katashina-mura , 950 m, 15.X.2000, H. Kamezawa leg. ( KUM) ; 2 male, 1 unsexed, Kirizumi spa, Yasunaka-shi , 29.IV.1958, Y. Shibata leg. ( KUM) ; 1 unsexed, ditto, 18. VI.1958, Y. Shibata leg. ( KUM) ; [Kanagawa Pref.]: 6 males, 1 female, 3 unsexed, Mt. Ishihodo-yama, Yamakita-machi, Kanagawa Pref. , 9.X.1995, T. Watanabe leg. ( KUM) . [Toyama Pref.]: 1 unsexed, Masagosawa, Mt. Tsurugi-dake, Tateyama-machi , 18.VII.1962, Y. Hayashi leg. ( KUM) ; [Fukui Pref.]: 6 male, 2 female, 2 unsexed, Kôkura, Imajo-chô , 14–18.X.1996, K. Ishida et al. leg. ( KUM) ; 1 male, Mt. Hyakuri-ga-take, Obama-shi , 5. V.1979, H. Sasaji leg. ( KUM) ; [Yamanashi Pref.]: 1 unsexed, Norogawa-deai , Minami-Alps-shi, 3.VII.1980, H. Yamazaki leg. ( KUM) ; 1 female, Kitazawa-tôge pass, Minami-Alps-shi, 28–30. VI.1980, H. Yamazaki leg. ( KUM) ; 1 male, near Dôsaka tunnel, Dôshi-mura , 16.XI.1996, T. Watanabe leg. ( KUM) ; [Nagano Pref.]: 1 unsexed, Hakuba-mura , 20.X.2007, T. Ito leg. (cI) ; 3 unsexed, Norikura, Matsumoto-shi , 1500 m, 26. V –1. VI.2008, H. Asaki leg. ( KUM) ; 1 unsexed, ditto, 2100 m, 27.VIII–02.IX.2008, H. Asaki leg. ( KUM) ; 5 unsexed, ditto, 1800 m, 18–22.IX2008, H. Asaki leg. ( KUM) ; 1 unsexed, Nagawa, Matsumoto-shi , 1500 m, 11–14. VI.2008, H. Asaki leg. ( KUM) ; 4 unsexed, ditto, 1600 m, 10–16.IX.2008, H. Asaki leg. ( KUM) ; 2 unsexed, ditto, 1500 m, 31.X–6.XI.2008, H. Asaki leg. ( KUM) ; [Gifu Pref.]: 2 unsexed, Hirayu, Takayama-shi , 12.X.1980, K. Konishi leg. ( KUM) ; 1 unsexed, Nishihotaka-guchi, Takayama-shi , 11. VI.1980 ( KUM) ; 2 unsexed, Mannami River, Miyagawa, Hida-shi , 5.XI.1980, S. Saito leg. ( KUM) ; 1 male, 1 female, 4 unsexed, Ooshirakawa, Shirakawa-mura , 26.X.1980, Y. Takai leg. ( KUM) ; 3 unsexed, Shirakawa-super-rindsuô, Shirakawa-mura , 11.X.1997, Y. Takai leg. ; 3 unsexed, Magari–Sanpôiwa, Hakusan, Shirakawa-mura , 13.X.1996, Y. Takai leg. ; 1 unsexed, Shirakawa-mura , 22.X.2006, K. Toyoshima leg. (cI) ; 1 unsexed, Mt. Fukube-ga-take, Minami-mura, Gujô-shi , 12. V.2002, A. Sugimura leg. ( KUM) ; [Kyoto Pref.]:

1 male, 1 female, Sugio-tôge pass, Ashiu, Nantan-shi , 15.X.1993, K. Setsuda leg., from Omphalotus japonicus (Kawam.) Kircham. & O. K. Mill. (KUM); [Nara Pref.]: Kamikitayama-mura, 4.X.2009, T. Ito leg., from mushroom ( KUM, cI); [Tottori Pref.]: 3 female, 2 unsexed, Daisen , 8.XI.1977, S. Naomi leg. ( KUM); [Okayama Pref.]: 1 male, 2 female, 4 unsexed, Wakasugi forest, Nishiawakura-son , 22.X.2009, T. Ito leg., from mushroom ( KUM, cI) ; 1 male, Wakasugi-tôge pass, Nishiawakura-son 8. V.1977, Watanabe leg. ( KUM); [Hiroshima Pref.]: 4 unsexed, Mt. Tateeboshi-yama , Saijô-chô , Shôbara-shi , 30.IV.2022, S. Inoue leg., by shifting leaf litter ( KUM); Oki Isls. : [Shimane Pref.] : 1 male, Minamidani-rindo, Dougo, Okinoshima-chô, 10.XI.2004, T. Watanabe leg. ( KUM); Shikoku : [Tokushima Pref.] : 4 male, 3 unsexed, Mt. Tsurugi-san , 15–17.X.1980, S. Naomi leg. ( KUM) .

Distribution. Japan: Hokkaido, Honshu, Oki Isls., and Shikoku ( Fig. 8 ).

Bionomics. The collecting records show that P. inflexa is distributed in lowlands to mountainous areas of Hokkaido, and mountainous areas to subalpine areas in Honshu and Shikoku. Adults appear in fall and spring to early summer (late September–November, April–early July), and are found in mushroom (e. g. Omphalotus japonicus (Kawam.) Kircham. & O. K. Mill ), animal droppings, and fallen leaves.

Diagnosis. Plesiochara inflexa is similar to P. japonica and P. nitida but can be distinguished by the sexual characters median lobe of aedeagus with apical lobe thin, entirely curved ventrally; sclerites 1 oblong narrowed ventrally, curved posteriorly at ventral apex; spermatheca with capsule ovate, almost as long as chamber.

Etymology. The specific name alludes to the shape of sclerites 4, which are strongly curved inwards.

Figures

FIGURE 6. Plesiochara inflexa sp. nov.: A, dorsal habitus; B–C, median lobe of aedeagus, lateral view; D–E, ditto, ventral view; F, spermatheca.

FIGURE 7. Plesiochara inflexa sp. nov., variation of median lobe of aedeagus in lateral view (A, C) and ventral view (B, D): A–B, near Dôsaka tunnel, Dôshi-mura, Yamanashi Pref.; C–D, Mt. Tsurugi-san, Tokushima Pref.

FIGURE 8. Distribution of Plesiochara inflexa sp. nov.: black star, type locality.

FIGURE 12. Posterior part of hypomera:A, Plesiochara japonica comb. nov.; B, P. nitida; C, P. rufula sp. nov.; D–F, P. inflexa sp. nov.: D, Nagahashi, Otaru-shi, Hokkaido Pref.; E, Wakasugi forest, Nishiawakura-son, Okayama Pref.; F, near Dôsaka tunnel, Dôshi-mura, Yamanashi Pref.