Stenoscelis cavirostris Inoue sp. nov.

[Japanese common name: Hekozu-kuchibuto-kikui-zômushi]

urn:lsid:zoobank.org:act: 8C8081B0-24AB-4899-B773-8350AB0271EB

(Figs 17–20, 25–29, 70–71 & 80)

Diagnosis. Stenoscelis cavirostris can be distinguished from the other congeners by the sexual dimorphism of the rostrum (dorsally concave in male and convex in female) (Figs 18, 20 & 70–71) and the apical part of striae widely dilated and reticulate, without distinct punctures (Fig. 80).

Redescription. Body length 2.4–3.0 mm; black, rather shiny; mouth parts, antennae, tarsi, and apical part of tibiae reddish brown; setae yellowish brown.

Rostrum 0.6 times as long as wide; dorsum concave in male, convex in female; dorsal surface reticulate, smoothly punctate; punctures minute, separated by interspace much longer than diameters; upper margin of scrobe directed to middle of eye; epistome with six long setae basally, with anterior margin obtusely projected at right side. Head with dorsal surface reticulate, smoothly punctate; punctures minute, separated by interspace much longer than 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 approximately 1–2 times as long as diameter.

Elytra 1.8 times as long as wide, 1.0–1.1 times as wide as and 2.1–2.4 times as long as prothorax, subparallel, conjointly rounded at apex; apex obtusely angulated in lateral view; striae rather shallow, with medium punctures separated by interspace almost as long as diameter; apical part of striae widely dilated and reticulate, without distinct punctures; apical part of intervals becoming indistinct as striae becoming dilated; 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 in a single row, each behind a granule, distinct and more than twice as long as granules.

Aedeagal body (Figs 25, 26) 2.0 times as long as wide, 2.0 times as long as apodeme, moderately arcuate laterally, gradually narrowed and moderately prolonged apically; apodeme attached sublaterally; endophallus with a pair of sclerite on subapical part; tegmen (Fig. 22) without dorsal part and paramere, with distinct manubrium; spiculum gastrale (Fig. 23) 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 (Fig. 29) with cornu falciform; collum slightly developed; ramus slightly developed.

Distribution. Japan: Kyushu, Amami-Ôshima Is. and Iheya Is.

Biological note. Some adults were collected by Flight Interception Trap (FIT) in Minami-ôsumi-chô, Kagoshima Prefecture.

Etymology. The new species is named after its dorsally concave rostrum in males.

Type material. Holotype (Figs 17 & 18): male (KUM), “ ē付ō南大DZḃ佐多ṉ塚 / Satahetsuka, Minamiôsumi-chô, / Kagoshima Pref., JAPAN / 22. V. 2021 Reo Itô leg.” (white card); “HOLOTYPE / Stenoscelis / cavirostris / des. S. Inoue, 2024” (red card). Paratypes: Japan: Kyushu: [Kagoshima Pref.]: 1 male, Mt. Hoyoshidake, Kimotsuki-cho, 19.III.2017, K. Narita leg. (KUM); 1 male, Hetsuka, Minamiôsumi-chô, 13.V.2020, R. Ito leg. (KUM); 1 male, 7 female, Satahetsuka, Minamiôsumi-chô, 29.V–5.VI.2021, R. Ito leg. (KUM); 2 male, ditto, by FIT, 22–29.IV.2021, R. Ito leg. (KUM); 1 male, 1 female, ditto, by FIT, 5–11.VI.2021 R. Ito leg. (KUM); 1 male, ditto, 22.V.2021, R. Ito leg. (KUM); Amami-Ôshima Is.: 1 male, Takabachi-yama, Sumiyô, 6.V.2014, M. Nishi leg. (KUM); Iheya Is: 1 male, Mt. Gayouyama, Gakiya, Iheya-son, 21.V.2019, T. Saeki leg. (KUM).