Bryothinusa itsuroi, 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 : 184

publication ID	https://doi.org/ 10.37520/aemnp.2021.009
publication LSID	lsid:zoobank.org:pub:27EA8466-6B29-40F4-8236-DD49061C523B
persistent identifier	https://treatment.plazi.org/id/03CB023B-AC1F-FF97-4E66-FD861368FCB8
treatment provided by	Carolina
scientific name	Bryothinusa itsuroi
status	sp. nov.

Treatment

Bryothinusa itsuroi View in CoL sp. nov.

( Figs 1K View Fig ; 2K View Fig ; 13 View Fig ; 20H View Fig ; 22 View Fig )

(Japanese name: Niseusucha-nagisa-hanekakushi)

Type material. Hඈඅඈඍඒඉൾ:J, JAPAN: HඈඇඌΗǕ: Kuruwa-kaigan,Akiya, Yokosuka-shi, Kanagawa-ken, 14.ix.2013, H. Ono ( KUM). Pൺ*©ൺඍඒඉൾඌ: HඈඇඌΗǕ: 1 ♀, 18 unsexed spec., Uraga-wan, Nishi-uraga,Yokosuka-shi, Kanagawa-ken, 4.iii.2013, H. Ono & I. Kawashima ( KUM, NMPC, BMNH); 7 JJ 3 ♀♀, 9 unsexed spec., same data as holotype ( KUM). KඒǕඌΗǕ: 1 J 1 ♀, 16 unsexed spec., Kakise, Takashima, Nagasaki-shi, Nagasaki-ken, 4.iii.2020, Y. Hisasue ( KUM). Nൺඇඌൾං-ඌΗඈඍත: 1 J 1 ♀, 1 unsexed spec., Mage-shima (near Tanega-shima), Kagoshima-ken, 14.x.2000, M. Maruyama (under stone on sandy beach, in a port) ( KUM).

Description. Body ( Fig. 1K View Fig ) small, about 1.7–1.9 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 elytra; eyes ( Fig. 2K View Fig ) large, setae present between about 29–31 facets, longer than tempora; antenna yellowish brown, almost equals to total length of head and pronotum; segment I as long as II, almost 3 times longer than III, and longer than XI; antennal segments VII–X almost wider than long.

Mouthparts ( Figs 13A–E View Fig ) with distribution of labral setae as in Figure 13A View Fig , with large and thick spiniform seta antero-laterally; mandibles ( Fig. 13B View Fig ) elongate triangle, asymmetrical, right with median tooth; median tooth shorter than 1/4 of mandibles; left without tooth, blunt at apex; maxilla with apical margin of lacinia ( Fig. 13C View Fig ) at right angle; at tip second spine very small, not obvious; 3 setae on inner margin of lacinia; labial palpus ( Fig. 13D View Fig ) with most setae located basally; mentum ( Fig. 13E View Fig ) with antero-lateral angles prolonged into spinose processes; anterior margin deeply truncate; small “v seta” far away from apical setae.

Pronotum shorter than elytra, as wide as head.

Elytra subquadrate, wider than pronotum; hind wings present but small, apparently flightless.

Male abdominal sternite VIII ( Fig. 13F View Fig ) with posterior margin slightly serrate. Median lobe of aedeagus ( Fig. 13H View Fig ) and dorsal view as in Figure 13I View Fig ; paramere ( Fig. 13J View Fig ) elongate.

Female abdominal sternite VIII ( Fig. 13G View Fig ) slightly serrate alike male on posterior margin. Spermatheca ( Fig. 13K View Fig ) of complicated shape, very small, shorter than 0.25 mm and several times coiled near base.

Measurements. BL 1.70–1.90, FBL 0.80–1.00, HL 0.31– 0.33, HW 0.38–0.41, PL 0.33–0.38, PW 0.40–0.41, EL 0.42–0.43, EW 0.41–0.43, HTL 0.33–0.39, AL 0.61–0.66, AS-I 0.10–0.11, AS-II 0.09–0.10, AS-III 0.03–0.04.

Differential diagnosis. In general appearance the species is very similar to B. fulvipennis sp. nov. and B. hokkaidensis sp. nov., but can be easily distinguished from them by the number of facets, the shape of the spermatheca, and the antennal segment I as long as II.

Etymology. The new species is named after Mr. Itsuro Kawashima, a scientific illustrator and researcher of fireflies, who helped collect the type series of this species in Kanagawa.

Distribution. Japan (Honshû: Kanagawa-ken; Kyûshû: Nagasaki-ken; Nansei-shotô: Kagoshima-ken: Tanega -shima).

Remarks. Unfortunately, one of the habitats in Uraga-wan, Kanagawa Prefecture has likely disappeared due to recent seawall construction. This species has a wide distribution but is found very locally where it occurs. A distribution map of examined specimens of this species in Japan is illustrated in Figure 22 View Fig .