Haliplus (Liaphlus) kotoshonis Kano & Kamiya, 1931

Figs 14, 18F Japanese name: Koto-kogashira-mizumushi

Haliplus kotoshonis Kano & Kamiya, 1931: 2. Satô 1985: 181, pls 33-37; Nakane 1985: 63; 1987: 30; Nakajima et al. 2020: 21.

Haliplus (Liaphlus) kotoshonis: Satô 1984: 2.

Haliplus diruptus J. Balfour-Browne, 1946: 436. Vondel 1995: 120, figs 71-79. Syn. nov.

Haliplus davidi Vondel, 1991: 92. [synonymized with Haliplus diruptus by van Vondel (2017)]

Material examined.

1 ex., Kagoshima Prefecture: Takara-jima, Tokara, 2.VII.1960, M. Satô leg. (EUMJ) ; 2 exs., Kagoshima Prefecture: Takara-jima, Tokara, 20.VII.1961, Y. Hama leg. (EUMJ) ; 7 exs., Kagoshima Prefecture: Takara-jima, Tokara, 2.VI.1962, M. Satô leg. (EUMJ) ; 2 exs., Okinawa Prefecture: Maesato, Ishigaki-jima, 4.IX.1975, T. Takahashi leg. (EUMJ) ; 1 ex., Okinawa Prefecture: Mt. Urabu-dake, Yonaguni-jima, 1.IV.1990, Y. Uchida leg. (EUMJ) ; 1 ex., Okinawa Prefecture: Shirahama, Iriomote-jima, 30.VI.2001, T. Nakamura leg. (TPM) ; 3 exs., Okinawa Prefecture: Okinawa-jima, Ryukyu, 26.VI.1995, T. Takara leg. (RUMF) .

Measurements

(n = 10). TL 3.39-4.94 (4.47) mm; HW 0.74-0.87 (0.80) mm; CED 0.31-0.38 (0.33) mm; PL 0.65-0.79 (0.73) mm; PW 1.29-1.53 (1.42) mm; EL 2.30-2.62 (2.42) mm; EW 1.76-2.01 (1.88) mm; BT 1.39-1.70 (1.50) mm; HW/CED 2.30-2.56 (2.38); PW/PL 1.87-2.04 (1.95); EL/EW 1.23-1.32 (1.30).

Biology.

The above specimens were collected from small ponds.

Immature stages.

Unknown.

Discussion.

This species was described based on one specimen from “Kotosho” (Orchid Island), Taiwan (Kano and Kamiya 1931). The type specimen is likely to have been lost (Mita et al. 2015), but the black marks on the dorsum are unique and the original description and figures are recognizable. Nakane (1985, 1987, 1990) has repeatedly pointed out that Haliplus diruptus J. Balfour-Browne, 1946 should be a junior synonym of the species, but a formal treatment has not been done. Judging from our investigation of the specimens and the description of van Vondel (1995), H. diruptus is treated as a junior synonym of this species in this paper. In addition, Haliplus davidi Vondel, 1991 was recorded from Japan (van Vondel 1998, 2003a), but was later treated as a junior synonym of H. diruptus (van Vondel 2017); therefore, the record of H. davidi from Japan is not H. diruptus but H. kotoshonis .

This study revealed that specimens of Haliplus angustifrons Régimbart, 1892 were mixed in with the specimens identified as " H. kotoshonis " from Japan. In a typical individual, the dorsal marks can easily distinguish between the two species. In particular, this species has a black mark on head, but the H. angustifrons does not have such a mark.

Distribution.

Japan: Nansei shoto (Takara-jima of Tokara-retto, Okinawa-jima, Ishigaki-jima, Iriomote-jima, Yonaguni-jima); Taiwan, China, Vietnam, Myanmar.