Plesiochara rufula, Inoue & Maruyama, 2022

Inoue, Shûgo & Maruyama, Munetoshi, 2022, Revision of the genus Plesiochara Sawada (Coleoptera: Staphylinidae: Aleocharinae), Zootaxa 5165 (4), pp. 501-519 : 515-517

Plesiochara rufula sp. nov.

Japanese common name: Aka-kusabira-hanekakushi

( Figs 9A–F , 10A–D , 11 )

Description. Body elongate, head, thorax and abdomen reddish brown to light brown, darker in head and posterior part of abdomen; antennae 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 without 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 directed to posterolateral corners obliquely.

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 = 1.41–1.54); surface of fore and middle tibia not covered with spines; hind tarsal segments I distinctly longer than combination of II and III.

Male: Median lobe of aedeagus ( Figs 9B–E , 10A–D ), rather small; apical lobe rather thin, curved ventrally; sclerites 1 convex at posterior margin; sclerites 4 indistinct; flagellum long.

Female: Spermatheca ( Fig. 9F ) with capsule ovate, almost as long as chamber.

Variation. Honshu: Median lobe of aedeagus with apical lobe not thickened at apex, moderately constricted in ventral view ( Fig. 10A–B ). Shikoku: Median lobe of aedeagus with apical lobe thickened at apex, moderately constricted in ventral view ( Fig. 9B–D ). Kyushu: Median lobe of aedeagus with apical lobe not thickened at apex, constricted rather strongly in ventral view ( Fig. 10C–D ).

Measurements. BL 4.4–5.5, FBL 2.50–3.07, HW 0.65–0.75, HL 0.69–0.78, PW 0.85–0.98, PL 0.78–0.90, EW 1.17–1.36, EL 0.92–1.14, HTL 1.12–1.35.

Type materials. Holotype: 1 male, Mt. Narabara-yama , 3.XI.1968, M. Takagi leg. ( KUM) . Paratype: JAPAN: Honshu: [Fukui Pref.]: 2 female, Kôkura, Imajo-chô , 14–18.X.1996 , K. Ishida leg. ( KUM); [Shiga Pref.]: 1 unsexed, Oisugi forest, Kutsuki , 28.X.2008 , T. Ito leg. (cI); [Kyoto Pref.]: 5 male, 6 female, 1 unsexed, Sugiotôge pass, Ashiu, Nantan-shi , 15.X.1993 , K. Setsuda leg., from Omphalotus japonicus (Kawam.) Kircham. & O. K. Mill. (KUM) ; 1 unsexed, Sasari-tôge pass, 26.X.2006 , T. Ito leg. (cI); [Okayama Pref.]: 1 male, 3 unsexed, Wakasugi Forest, Nishiawakura-son , 22.X.2009 , T. Ito leg., from mushroom ( KUM, cI); [Hiroshima Pref.]: 2 male, 90 unsexed, Mt. Tateeboshi-yama, Saijô-chô, Shôbara-shi , 1175 m, 14.X.2019 , Y. Senda leg., from Omphalotus japonicus (Kawam.) Kircham. & O. K. Mill. (HMNH, KUM) ; 1 unsexed, ditto, 30.IV.2022 , S. Inoue leg., by shifting leaf litter ( KUM); Shikoku: [Ehime Pref.]: 3 male, 3 female, 5 unsexed, Mt. Narabara-yama , 3.XI.1968 , M. Takagi leg. ( HMNH, KUM); 1 male, 1 unsexed, Mt. Shiratsue, Matsuyama-shi , 780 m, 10–23.X.1986 , T. Nagata leg. ( HMNH, KUM); 1 male, 1 unsexed, Mt. Koya, Nomura-chô, Seiyo City , 1250–1300 m, 28.XI.2008 , T. Kurihara leg. ( HMNH, KUM); 2 unsexed, Saragamine, Kumakôgen Town , 1100–1270 m, 4.X.2008 , T. Kurihara leg. ( HMNH, KUM); Kyushu: [Kumamoto Pref.]: 3 male, 2 female, 4 unsexed, Kirihagi, Yamato-chô , 15.X.1993 , Y. Tomishima leg. ( KUM); 2 unsexed, Mt. Heike-yama, Gokanosho, Yashiro-shi , 17.X.1988 , S. Naomi leg. ( KUM); 1 male, Naidaijin, Yamato-chô , 22.X.1982 , M. Matsuzaki leg. ( KUM); 1 male, 1 female, 3 unsexed, Mt. Ichifusayama, Minakami-mura , 13.X.1995 , Y. Tomishima leg. ( KUM).

Distribution. Japan: Honshu, Shikoku, and Kyushu ( Fig. 11 ).

Bionomics. The collecting records show that P. rufula is distributed in mountainous areas. Adults appear in fall and spring (October–November, April), and are found in mushroom (e. g. Omphalotus japonicus ) and fallen leaves.

Diagnosis. P. rufula can be easily distinguished from other congeners by the following character states: head, thorax, and abdomen reddish brown to light brown, darker in head and posterior part of abdomen; dorsal surface of head and pronotum without reticulation; basal impressions of abdominal tergites III–VII with large pores. P. rufula is similar to P. inflexa regarding the median lobe of the aedeagus, but can be distinguished by the following characters: size smaller; sclerites 1 convex at posterior margin, not curved posteriorly at ventral apex; sclerites 4 indistinct.

Etymology. The specific name alludes to the reddish body.

Figures

FIGURE 9. Plesiochara rufula sp. nov.: A, dorsal habitus; B–C, median lobe of aedeagus, lateral view; D–E, ditto, ventral view; F, spermatheca.

FIGURE 10. Plesiochara rufula sp. nov., variation of median lobe of aedeagus in lateral view (A, C) and ventral view (B, D): A–B, Wakasugi forest, Nishiawakura-son, Okayama Pref.: C–D, Kirihagi, Yamato-chô, Kumamoto Pref.

FIGURE 11. Distribution of Plesiochara rufula sp. nov.: black star, type locarity.