Halorhadinus Sawada, 1971

Tasaku, Yuto, Ono, Hiroki & Maruyama, Munetoshi, 2023, Review of the intertidal rove beetle tribe Liparocephalini Fenyes (Coleoptera, Staphylinidae, Aleocharinae) from Japan, Zootaxa 5383 (3), pp. 251-296 : 280

Genus Halorhadinus Sawada, 1971

[Japanese name: Iso-hanekakushi-zoku]

( Fig. 20 )

Halorhadinus Sawada, 1971: 92 (original description; type species: H. aequalis Sawada, 1971 ); Ahn, 2001: 123 (redescription; key to species; phylogenetic analysis); Maruyama & Hayashi, 2009: 72 (supplementary description; key to species; systematic position); Ono & Maruyama, 2014: 42 (description; key to species).

Diagnosis. This genus is similar to Amblopusa in overall bodyform ( Figs. 17 & 20A ), characteristics of mentum and maxilla ( Figs. 19B & D ; 20C & E ) and apical lobe of paramere ( Figs. 18G & 20G ) but can be distinguished by the following characteristics: hind wings sometimes present, female spermatheca coiled many times, mandible elongate ( Fig. 20F ), labrum as long as wide ( Fig. 20B ), and two medial setae present on prementum ( Fig. 20D ). Comparisons with other genera of Liparocephalini , see the key to genera and diagnosis of Amblopusa .

Habitat. All species of this genus mainly have been collected from gravel beaches and rarely from under driftwood on sandy beaches.

Remarks. Eight species of this genus are recorded from Japan. They were relatively recently redescribed or described, and their diagnostic characters are well illustrated ( Maruyama & Hayashi, 2009; Ono & Maruyama, 2014). Therefore, only the diagnosis of the genus is mentioned here. See, Maruyama & Hayashi (2009) and Ono & Maruyama (2014) for species identification. Our illustrations are based on the type species H. aequalis .

Distribution. Japan: Hokkaidô, Honshû, Shikoku, Kyûshû; Korea.

Figures

FIGURE 17 Habitus of Amblopusa spp. A, A. magna; B, A. pacifica; C, A. brevipes; D, A.hokkaidona. Scale bar: 1.0 mm.

FIGURE 18 Genitalia of Amblopusa spp. A & B, A. magna (A, median lobe of aedeagus; B, spermatheca); C & D, A. pacifica (C, median lobe of aedeagus; D, spermatheca); E–G, A. brevipes (E, median lobe of aedeagus; F, spermatheca; G, apical lobe of paramere). Scale bars: 0.1 mm.

FIGURE 19 Mouth parts of Amblopusa brevipes. A, labrum (right side, dorsal view; left side, ventral view (epipharynx)); B, mentum; C, labium; D, maxilla; E, right mandible. Scale bars: 0.1 mm.

FIGURE 20 Halorhadinus aequalis. A, Habitus; B, labrum (right side, dorsal view; left side, ventral view (epipharynx)); C, mentum; D, labium; E, maxilla; F, right mandible; G, apical lobe of paramere. Scale bars: 1.0 mm for A; 0.1 mm for B–G.