Bryothinusa constricta, Liu & Ono & Maruyama, 2021

Liu, Tian-tian, Ono, Hiroki & Maruyama, Munetoshi, 2021, Revision of the intertidal rove beetle genus Bryothinusa from Japan (Coleoptera: Staphylinidae: Aleocharinae), Acta Entomologica Musei Nationalis Pragae (Acta. Ent. Mus. Natl. Pragae) 61 (1), pp. 163-201 : 179

publication ID	https://doi.org/ 10.37520/aemnp.2021.009
publication LSID	lsid:zoobank.org:pub:27EA8466-6B29-40F4-8236-DD49061C523B
DOI	https://doi.org/10.5281/zenodo.10532127
persistent identifier	https://treatment.plazi.org/id/03CB023B-AC1A-FF92-4E54-F94F13F1F918
treatment provided by	Carolina
scientific name	Bryothinusa constricta
status	sp. nov.

Treatment

Bryothinusa constricta View in CoL sp. nov.

( Figs 1H View Fig ; 2H View Fig ; 10 View Fig ; 22 View Fig )

(Japanese name: Kubire-nagisa-hanekakushi)

Type material. Hඈඅඈඍඒඉൾ: J, JAPAN: HඈඇඌΗǕ: Futtsu-misaki, Futtsu-shi, Chiba-ken, 1.v.2014, H. Ono ( KUM). Pൺ*©ൺඍඒඉൾඌ: HඈඇඌΗǕ: 3 ♀♀, 6 unsexed spec., same locality as holotype, 28.v.2010, H. Ono ( KUM); 2 JJ 5 ♀♀, 10 unsexed spec., same data as holotype ( KUM, NMPC, BMNH); 1 ♀, 4 unsexed spec., Izumo, Koryô-chô, Shimane-ken, 3.ix.2007, T. Hayama ( KUM).

Description. Body ( Fig. 1H View Fig ) small, about 1.7–2.0 mm in length, covered with minute setae. Abdomen almost black and darker than head and pronotum; elytra lighter than pronotum; legs yellowish brown.

Head evenly rounded, more or less produced anteriorly, wider than long, shorter than pronotum and as long as elytra; eyes ( Fig. 2H View Fig ) large, setae present between about 20–22 facets, slightly longer than tempora length; antenna yellowish brown, equal to total length of head and pronotum; segment I 1.6 times longer than II, almost 3.5 times longer than III, and longer than XI; antennal segments III–X almost wider than long, and VI–VII wider than width of III–IV.

Mouthparts ( Figs 10A–E View Fig ) with distribution of labral setae as in Figure 10A View Fig , with large and thick spiniform seta at antero-laterally; mandibles ( Fig. 10B View Fig ) elongate triangle, asymmetrical, right mandible with median tooth; median tooth shorter than 1/4 of mandibles; left mandible without tooth, blunt at apex; maxilla with apical margin of lacinia ( Fig. 10C View Fig ) at right angle; at tip with two spines very small and not closely interdigitating; 3 setae on inner margin of lacinia; labial palpus ( Fig. 10D View Fig ) with most setae located basally; mentum ( Fig. 10E View Fig ) with antero-lateral angles prolonged into spinose processes; anterior margin deeply truncate; small “v seta” far away from apical setae.

Pronotum longer than elytra, wider than head.

Elytra widened apically, wider than long, almost as wide as pronotum; hind wings present but very small, apparently flightless.

Male abdominal sternite VIII ( Fig. 10F View Fig ) with posterior margin slightly serrate. Median lobe of aedeagus as in Figures 10H, I View Fig ; paramere ( Fig. 10J View Fig ) elongate.

Female abdominal sternite VIII ( Fig. 10G View Fig ) slightly serrate alike male on posterior margin. Spermatheca ( Fig. 10K View Fig ) simplified in shape, about 1.5 times coiled near base.

Measurements. BL 1.70–2.00, FBL 0.80–1.00, HL 0.30– 0.31, HW 0.35–0.39, PL 0.30–0.33, PW 0.38–0.40, EL 0.29–0.30, EW 0.36–0.40, HTL 0.30–0.31, AL 0.61–0.67, AS-I 0.11–0.14, AS-II 0.06–0.09, AS-III 0.03–0.04.

Differential diagnosis. In general appearance, the species is similar to B. sakishimana , but easily distinguished from it by the elytral shape being narrowed anteriorly and the shape of the spermatheca.

Etymology. Bringing attention to the constricted body shape; adjective.

Distribution. Japan (Honshû: Chiba-ken, Shimane-ken).

Remarks. This species is found mainly on the Japan Sea coast of western Japan and east of Tôkyô Bay, but it is probably occurring in other areas of mainland Japan. A distribution map of examined specimens of this species in Japan is illustrated in Figure 22 View Fig .