Bryothinusa japonica Liu, Ono & Maruyama, 2020

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 : 176

Bryothinusa japonica Liu, Ono & Maruyama, 2020

( Figs 1F ; 2F ; 8 ; 21A–B, G ; 22 )

(Japanese name: Nippon-nagisa-hanekakushi)

Bryothinusa japonica Liu, Ono & Maruyama, 2020: 586 (original description; type locality: Japan, Kyûshû, Fukuoka).

Material examined. JAPAN: HඈඇඌΗǕ: 7 JJ 1 ♀, 22 unsexed spec., Matsumi-ga-ura,Ôchiba, Kosai-shi, Shizuoka-ken, 11.iv.2004, Y.Tahira; 8 unsexed spec., Miya-gawa, Iso-chô,Ise-shi, Mie-ken, 8.vi.2008, K.Aki-

ta; 4 JJ 2 ♀♀, 67 unsexed spec., Kumozu-gawa, Karasu-chô, Mie-ken, 15.v.2004, K. Akita; 2 JJ 1♀, 26 unsexed spec., Mouth of Kansa-gawa, Nansei-chô, Mie-ken, 5.v.2008, K. Akita; 4 JJ 4 unsexed spec., Mouth of Yoshii-gawa, Nishikôzai, Okayama-shi, Okayama-ken, 24.x.2004, O. Yamaji; 2 JJ 4 ♀♀, 6 unsexed spec., Mitsuguchi-kaigan, Yasuura-chô, Kure, Hiroshima-ken, 28.vii.2019, H. Yoshigou. SΗංκඈκඎ: 2 JJ 5 ♀♀, 112 unsexed spec., Shimoda, Shimanto-shi, Kôchi-ken, 21.iv.2012, M. Maruyama; 1 J 4 ♀♀, 2 unsexed spec., Kagami-gawa, Takajô-machi, Kôchi-shi, Kôchi-ken, 20.vi.2008, H. Fujimoto. KඒǕඌΗǕ: 3 JJ 1 ♀, 4 unsexed spec., Sunosaki, Imazu, Nishi-ku, Fukuoka-shi, Fukuoka-ken, 16.x.2020, T. Liu & T. Nozaki; 8 unsexed spec., Mouth of Sakurai-gawa, Shima-Nogita, Itoshima-shi, Fukuoka-ken, 21.iv.2020, Y. Hisasue; 1 ♀, same locality, 11.x.2018, Liu et al. Deposited at KUM but some will be distributed to NMPC and BMNH.

Additional description. Number of facets 23–25 as Fig. 2F . Antennal segment I 1.2 times longer than II, almost 2.4 times longer than III, and longer than XI. Mouthparts with median tooth longer than 1/4 of mandibles; 6 setae on inner margin of lacinia; male and female abdominal sternite VIII, spermatheca and aedeagus as in Figure 8 . See also Lංඎ et al. (2020).

Differential diagnosis. In general appearance, the species is closely allied to B. tsutsuii , B. algarum , B. koreana and B. yoshigoui sp. nov., but easily distinguished from them by the apical part of spermatheca without granule-like projections.

Distribution. Japan (Honshû: Chiba-ken, Shizuoka-ken, Mie-ken, Ôsaka-fu, Hyôgo-ken, Wakayama-ken, Okayama-ken, Hiroshima-ken, Yamaguchi-ken; Shikoku: Kagawa-ken, Ehime-ken, Kôchi-ken; Kyûshû: Fukuoka-ken).

Remarks. About 200 specimens were collected before the original description but they were not included in the type series due to the difficulty of identification. There was considerable variation in the colouration of the specimens, ranging from light brown to brown, but it is unclear whether this is due to geographical variation or to the methods in which the specimens were preserved.

This species is quite common in sandy to mud flats in estuaries in Japan, mainly west of Kantô District. A distribution map of examined specimens of this species in Japan is illustrated in Figure 22 .

Figures

Fig. 1. Habitus of Bryothinusa spp. A – B. algarum Sawada, 1971; B – B. minuta (Sawada, 1955); C – B. tsutsuii (Sawada, 1955); D – B. koreana Ahn & Jeon, 2004; E – B. yoshigoui sp. nov.; F – B. japonica Liu, Ono & Maruyama, 2020; G – B. sakishimana Sawada, 1991; H – B. constricta sp. nov.; I – B. hokkaidensis sp. nov.; J – B. fulvipennis sp. nov.; K – B. itsuroi sp. nov.; L – B. aikoae sp. nov.; M – B. okinawana sp. nov.; N – B. nigra sp. nov.; O – B. nakanei (Sawada, 1955); P – B. moriguchii sp. nov.; Q – B. gangjinensis Ahn & Jeon, 2004. Scale bars: 1.00 mm.

Fig. 2. Compound eyes of Bryothinusa spp.A – B. algarum Sawada, 1971; B – B. minuta (Sawada, 1955); C – B. tsutsuii (Sawada, 1955); D – B. koreana Ahn & Jeon, 2004; E – B. yoshigoui sp. nov.; F – B. japonica Liu, Ono & Maruyama, 2020; G – B. sakishimana Sawada, 1991; H – B. constricta sp. nov.; I – B. hokkaidensis sp. nov.; J – B. fulvipennis sp. nov.; K – B. itsuroi sp. nov.; L – B. aikoae sp. nov.; M – B. okinawana sp. nov.; N – B. nigra sp. nov.; O – B. nakanei (Sawada, 1955); P – B. moriguchii sp. nov.; Q – B. gangjinensis Ahn & Jeon, 2004. Scale bars: 0.05 mm.

Fig. 8. Bryothinusa japonica Liu, Ono & Maruyama, 2020. A – labrum; B – mandible, dorsal view; C – lacinia, dorsal view; D – labium; E – mentum; F – male sternite VIII; G – female sternite VIII; H – median lobe, ventral view; I – median lobe, lateral view; J – paramere; K – spermatheca. Scale bars: 0.1 mm. Modified from Lංඎ et al. (2020).

Fig. 21. Collection localities of Bryothinusa species in Japan: A – B. koreana Ahn & Jeon, 2004 and B. japonica Liu, Ono & Maruyama, 2020 in Shima-nogita, Fukuoka; B – B. aikoae sp. nov., B. fulvipennis sp. nov., B. japonica and B. nigra sp. nov. in Kuroto, Chiba; C – B. hokkaidensis sp. nov. in Shunkunitai, Hokkaidô; D – B. nigra sp. nov. and B. tsutsuii (Sawada, 1955) in Edateku-jima; E – B. nakanei (Sawada, 1955) in Nagura-anparu, Ishigaki-jima; F – B. gangjinensis Ahn & Jeon, 2004 in Iki-no-matsubara, Fukuoka; G – B. algarum Sawada, 1971, B. japonica and B. minuta (Sawada, 1955) in Sunosaki, Fukuoka.

Fig. 22. Map of examined specimens of Bryothinusa spp. from Japan: white inverted triangle – B. algarum Sawada, 1971; black inverted triangle – B. minuta (Sawada, 1955); white star – B. tsutsuii (Sawada, 1955); black star – B. koreana Ahn & Jeon, 2004; black square – B. yoshigoui sp. nov.; white triangle – B. japonica Liu, Ono & Maruyama, 2020; black diamond – B. sakishimana Sawada, 1991; white diamond – B. constricta sp. nov.; white square – B. hokkaidensis sp. nov.; black triangle – B. fulvipennis sp. nov.; double circle – B. itsuroi sp. nov.; arrow – B. aikoae sp. nov.; black hart – B. okinawana sp. nov.; circled dot – B. nigra sp. nov.; white circle – B. nakanei (Sawada, 1955); white hart – B. moriguchii sp. nov.; black circle – B. gangjinensis Ahn & Jeon, 2004.