Stenoscelis reniformis Inoue, 2025

Stenoscelis reniformis Inoue sp. nov.

[New Japanese common name: Minami-kuchibuto-kikui-zômushi]

urn:lsid:zoobank.org:act:8DEB2F04-DE21-4314-994A-32FA8788811C

( Figs 42–43 View FIGURES 40–47 , 53–57 View FIGURES 53–57 , 75 View FIGURE 74–77 & 83 View FIGURE 78–83 )

Stenoscelis sp. 2 : Morimoto, 1983.

Diagnosis. Stenoscelis reniformis is very similar to S. matobai , S. gracilitarsis , and S. ogasawarensis , but can be distinguished from them by the sclerotized structure on the subapical part of endophallus being reniform and convex ventrally ( Fig. 53–54 View FIGURES 53–57 ) (flat and ovate in the other species).

Description. Body length 2.9–3.6 mm; black, rather shiny; mouth parts, antennae, tarsi, and apical part of tibiae reddish brown; setae yellowish brown.

Rostrum 0.6–0.7 times as long as wide; dorsum convex; dorsal surface reticulate, rugosely punctate; punctures small, separated by interspace approximately 1–2 times as long as diameter; upper margin of scrobe directed to lower margin of eye; epistome with six long setae basally, with anterior margin obtusely projected at right side. Head with dorsal surface reticulate, smoothly punctate; punctures small, separated by interspace approximately 2–4 times as long as diameter; interocular area with a shallow fovea; eye round, hardly convex.

Antennae with club subcircular, slightly wider than long; funicle 7-segmented, slightly longer than club.

Prothorax 0.8–0.9 times as long as wide, widest before base, gradually narrowed anteriorly, weakly sinuate laterally; anterior margin weakly sinuate in middle or not; subapical constriction distinct on lateral side, obsolete on dorsal side; disc reticulate, rugosely punctate; punctures medium, separated by interspace almost as long as or narrower than diameter.

Elytra 1.6 times as long as wide, 1.0–1.1 times as wide as and 2.0–2.1 times as long as prothorax, subparallel, conjointly rounded at apex; apex obtusely angulated in lateral view; striae rather deep, with medium punctures separated by interspace approximately 1–2 times as long as diameter; apical part of striae moderated, not dilated or reticulate; second stria distinctly separated from base; intervals somewhat convex, with an irregular row of small puncture; base of second to third or fourth interval rugosely punctate-granulate; apical half of ninth interval and tenth interval carinate; granules of intervals arranged in a single row, indistinct basally, distinct and conical on declivity; setae on declivity arranged irregularly in one or two rows, as long as or shorter than granules.

Aedeagal body 1.4 times as long as wide, 0.8 times as long as apodeme, subparallel, rapidly narrowed and weakly prolonged apically; apodeme attached laterally; endophallus with a large sclerotized structure on dorsal side of subapical part; the structure reniform, convex ventrally, with a pair of short projection on dorsal side, with short hairs, without separated part basally; tegmen without dorsal part and paramere, with distinct manubrium; spiculum gastrale gradually curved to right side apically, not expanded apically; sternite VIII divided, with several long setae apically; without spinulate apical membranous area.

Spiculum ventral not bifurcate at base; spermatheca with cornu falciform; collum not developed; ramus not developed.

Distribution. Japan: Honshu, the Izu Isls. (Mikurajima Is.), Shikoku, Kyushu, Tsushima Is., Tokara Isls. (Nakanoshima Is.), Amami-Ôshima Is., Okinawa Is., and Iriomote Is.

Biological note. The adults were collected from the tunnels bored in dead trees ( Figs 86 & 87 View FIGURE 84–89 ) and fallen branches of broad-leaved trees ( Fig. 88 View FIGURE 84–89 ) in Jôyama, Fukuoka Pref. The larvae were also found inside the fallen branch in Jôyama, from which the adults were collected ( Fig. 89 View FIGURE 84–89 ).

Etymology. The new species is named after its reniform sclerotized structure of endophallus.

Type material. Holotype ( Figs 42 & 43 View FIGURES 40–47 ): male ( KUM), “ Jôyama, Ryôgenji , Munakata-shi, Fukuoka Pref., Japan, 29.V.2020 (under bark of dead tree), N. TSUJI & Shugo INOUE leg.” (white card); “ ạ̎āṯ像İĸ山 / Mt. Jôyama, Munakata-shi, / Fukuoka Pref., Kyushu, Japan. / 29.V.2020. (from dead trunk) / Naomichi Tsuji & Shûgo Inoue” (white card); “HOLOTYPE / Stenoscelis / reniformis / des. S. Inoue, 2024” (red card) . Paratypes: Japan: Honshu: [Wakayama Pref.]: 1 male, Koza, 20.IX.1962, K. Morimoto leg. ( KUM) ; the Izu Isls.: Mikurajima Is. : 1 male, Tanteiro-no-mori , 13.VI.2010, J. Aoki leg. ( KUM) ; Shikoku: [Kôchi Pref.]: 1 male, Ashizuri-Cape, Matsuo , Tosashimizu-City, 27.I.2024, R. Tamura leg. ( KUM) ; Kyushu: [Fukuoka Pref.]: 1 male, Asamayama, Buzen-shi , 2.V.2010, K. Kido leg. ( KUM) ; 1 male, Mt. Jô-yama , Munakata-shi, 17–18.VII.2016, S. Imada leg. ( KUM) ; 1 male, Jôyama , Munakata-shi, em. 7.IV.2017, K. Narita leg. ( KUM) ; 1 male, 1 unsexed, Jôyama, Ryôgenji , Munakata-shi, alt. 150–250 m, 29.V.2020, Shugo Inoue leg. ( KUM) ; 5 male, 6 female, 9 unsexed, Jôyama, Munakata-shi, collected from dead trunk, 29.V.2020, N. Tsuji & Shugo Inoue leg., ( KUM) ; 2 male, 1 female, 6 unsexed, Jôyama, Ryôgenji , Munakata-shi, 14.IX.2023, Shugo Inoue leg. ( KUM) ; [Kagoshima Pref.]: 1 male, Mt. Hoyoshidake , 10–17.VII.1991, R. Noda leg. ( TUA) ; 1 male, 1 female, Mt. Hoyoshidake , Kimotsuki, 19.III.2017 (collecting dead trees), VII.2017 (emerge), R. Ito leg. ( KUM) ; 1 male, 1 female, Sugiyamadani Valley , Minamiôsumi-T., 31.VII.2017, N. Tsuji leg. ( KUM) ; 1 male, Sata-hetsuka , Minami-ôsumi-chô, 12.IX.2020, S. Imada leg. ( KUM) ; 1 male, Satahetsuka , Minamiôsumi-chô, 18.IX.2021, R. Ito leg. ( KUM) ; Tsushima Is.: 1 male, Tatsura-yama , 2.VI.1988, S. Nomura leg. ( KUM) ; Tokara Isls.: Nakanoshima Is .: 1 male, 23.V.1962, M. Sato leg. ( KUM) ; 1 male, Funakura–Mitake, 18.VII.1984, Y. Takai leg. ( KUM) ; 1 male, Negami-dake , 3.V.2000, T. Mikage leg. ( KUM) ; Amami-Ôshima Is.: 2 male, Okumata , 5.VIII.1969, K. Yamada leg. ( KUM) ; 1 male, Nishinakama, 3–5.VIII.1969, H. Makihara leg. ( KUM) ; 1 male, 4 female, 1 unsexed, Minamikawa Forestry Road, Setouchi , III.1985 – VI.1986, K. Hosokawa leg. ( KUM) ; 1 male, Uken, 25.V.2004, K. Takahashi leg. ( KUM) ; 1 male, Santarô-tôge, Sumiyô-son , 29.IV.2010, K. Takahashi leg. ( KUM) ; 1 male, Uken, Uken-son , 6.IV.2010, K. Takahashi leg. ( KUM) ; Okinawa Is.: 1 male, Mt. Terukubi-yama , Kunigami-son, 6.X.2017, K. Narita leg. ( KUM) ; Iriomote Is.: 1 male Shirahama , 31.VIII–5.IX.1969, H. Makihara leg. ( KUM) .

Remarks. I examined the specimen (1 male from Shirahama, Iriomote Is.) which was referred to as Stenoscelis sp. 2 in Morimoto (1983) and identified it as S. reniformis by the reniform sclerotized structure of male aedeagus. According to Morimoto (1983), Stenoscelis sp. 2 was characterized by the base of second to fourth elytral intervals being flat, but this character state seems to be an anomalous condition unique to this individual.