Haliplus (Nipponiplus) japonicus Sharp, 1873

Figs 4, 18C Japanese name: Kubiboso-kogashira-mizumushi

Haliplus japonicus Sharp, 1873: 55. Kamiya 1936: 44; Satô 1985: 181; Nakane 1963a: 55; 1985: 62; 1987: 29; Matsui 1992: 2; Vondel 1995: 122; Tomisawa 2012: 42; Matsuo and Fukagawa 2016: 51; Mitamura et al. 2017: 138; Hayashi and Kadowaki 2019: 25; Nakajima et al. 2020: 20.

Haliplus (Haliplus) japonicus: Satô, 1984: 1; Vondel 2003a: 31; Vondel et al. 2006: 250.

Haliplus (Nipponiplus) japonicus: Vondel 2019: 22.

Haliplus brevior Nakane, 1963a: 55. Nakane 1985: 62; 1987: 29. [synonymized with H. minutus by Satô (1984) but with H. japonicus by van Vondel et al. (2006)]

Material examined.

Specimens examined in this study are listed in Suppl. material 1.

Measurements

(n = 10). TL 2.69-4.08 (3.79) mm; HW 0.62-0.69 (0.67) mm; CED 0.29-0.32 (0.30) mm; PL 0.55-0.66 (0.62) mm; PW 1.05-1.20 (1.12) mm; EL 1.99-2.20 (2.10) mm; EW 1.50-1.71 (1.60) mm; BT 1.12-1.28 (1.19) mm; HW/CED 2.12-2.35 (2.24); PW/PL 1.65-2.04 (1.76); EL/EW 1.25-1.34 (1.32).

Biology.

This species usually lives in fresh waters with abundant aquatic plants such as ponds, paddies, and streams (Nakajima et al. 2020). The larvae eat Zygnemataceae algae (Hayashi 2015). The adults were collected by sweep netting in shallow waters and are rarely attracted by light traps (Hayashi 2015). The pupation in mud with a pupal chamber was accomplished by laboratory rearing (Hayashi 2015).

Immature stages.

The color photographs were provided by Mitamura et al. (2017) and Nakajima et al. (2020).

Distribution.

Japan: Hokkaido, Honshu, Shikoku, Kyushu, Noto-jima, Oki, Goto-retto, Taka-shima, Amakusa-shoto; China, Far East Russia.