Pseudatheta taiwanensis Pace, 2008

Hashizume, Takuto, Yamamoto, Shûhei & Maruyama, Munetoshi, 2023, Revision of the Genera Pseudatheta Cameron and Phymatura Sahlberg (Coleoptera, Staphylinidae, Aleocharinae) from Japan, Zootaxa 5319 (1), pp. 27-47 : 34-35

Pseudatheta taiwanensis Pace, 2008

( Figs. 1B , 4 , 5D–F )

[Japanese name: Taiwan-miiro-kinokotsuyakeshi-hanekakushi]

Pseudatheta taiwanensis Pace, 2008: 146 (original description;

type locality: “ Taiwan, Kaohsiung Hs., for. abv. Tona For. Sta. 1100 m ”).

Materials examined. JAPAN: [Hokkaido]: 2 males, Midorimachi, Assabu-chô , 8 IX 2022, T . Hashizume leg. ( KUM); 2 males, Ôsawaguchi, Nopporo-shinrin-kôen, Ebetsu-shi, 16–19 VI 2001, S. Hori leg. ( KUM); 1 male, 1 female, Kannonzawa-rindô, Minami-ku, Sapporo-shi , 8 VIII 2021, T . Nozaki leg. ( KUM); [Saitama-ken]: 1 male, 2 females, Futago-yama, 28 VIII 1984, H. Oda leg. ( KUM) ; [Tokyo-to]: 1 male, Nippara, Okutama-machi , 15 VI 1997, K. Haga leg. ( KUM); 1 male, 1 female, same data, but 5 V 1998 ( KUM) ; [Tottori-ken]: 1 male, Hyô-no-sen, Wakasa-chô, 6–9 VIII 1968, I. H. B. C. ( EUM) ; [Fukuoka-ken]: 2 males, 1 female, Hiko-san, Soeda-machi , 23 V 2020, S. Inoue leg. ( KUM); 1 male, 2 female, Hiko-san , 7 V 1971, K. Takeno leg. ( KUM); 1 male, Hiko-san, 15 X 1968, M.- T . Ch ̊jô leg. ( KUM) ; [Kumamoto-ken]: 1 male, Shiratori-yama, Izumimachi Momigi, Yatsushiro-shi , 14 V 2021, S. Inoue leg. ( KUM); [Oita-ken]: 1 male, Kyûsuikei, Kokonoe-machi , 31 V –10 VI 2011, S. Imasaka leg. ( KUM).

Redescription. Measurements (n = 5): BL ≈ 1.90–2.13; FBL: 1.09–1.25; HL: 0.34–0.38; HW: 0.39–0.44; PL: 0.38–0.40; PW: 0.53–0.59; EL: 0.36–0.43; EW: 0.62–0.72.

Relative length of antennomeres I–XI (n = 1): 20: 22: 18: 10: 12: 13: 13: 11: 12: 12: 33. Ratio of length/width of antennomeres I–XI (n = 1): 1.90: 2.27: 1.86: 0.80: 0.73: 0.78: 0.77: 0.63: 0.73: 0.69: 1.79.

Body ( Fig. 1B ) reddish brown; head darker; posterolateral areas of elytra darker; abdominal segments V–VII darker.

Head almost as long as wide, HW/HL:1.07–1.23; surface densely covered with setae.Antenna with antennomeres I–III and XI longer than wide, antennomeres IV–X wider than long; antennomeres I and II with rounded distal end, antennomeres III–X strongly angulated near distal end, antennomere XI oval.

Pronotum transverse, PW/PL: 1.35–1.45, PW/HW: 1.31–1.41; surface densely covered with setae, finely punctured, without microsculpture; posterior margin slightly bisinuate. Elytra wider than long, EW/EL: 1.60–1.79, EL/PL: 0.97–1.06, EW/PW: 1.14–1.22; surface densely covered with setae and finely punctured; posterior margin sinuate near posterolateral corners. Hind wings well developed; flabellum with one seta. Mesoventrite without longitudinal carina; mesoventral process extended to slightly beyond middle of mesocoxal cavities, with rounded apex; metaventral process shorter than mesoventral process, with rounded apex; isthmus present.

Abdomen slightly narrowed posteriad; surface densely covered with setae.

Male. Elytra with a pair of small tubercles at about posterior 1/3 on sutural margin. Sternite VI with small medial lobe on posterior margin. Tergite VII with a tubercle on posteromedian area. Tergite VIII ( Fig. 5D ) with a tubercle on median area; three to five processes on each side of posterior margin, outer ones slightly curved, longer and sharper than the others.Aedeagus as in Fig. 5E ; median lobe with large basal bulb; apical process broad, parallel to near apex, not dilated in lateral view, apical end thin and elongated, apex pointed; flagellum moderately long.

Female. Spermatheca ( Fig. 5F ) curved twice, with a transverse band-like structure at base of distal portion; distal portion elongated, U-shaped; median portion elongated, slightly curved; proximal portion longer than wide.

Distribution. Japan (Hokkaido, Honshu, Kyushu)—new record; Taiwan.

Remarks. This species can be distinguished from Ps. crenulicauda by the non-dilated, parallel-sided apical process of its aedeagus. Most of the aedeagi of specimens from Japan have an abruptly narrowed and protruding apical part on their apical process, which is not seen in Pace’s illustrations of the specimen from Taiwan (2008). Similar aedeagi are seen in a few Japanese specimens, but it is likely that they were damaged. While we cannot rule out the possibility that the original description of Ps. taiwanensis was based on a specimen with a damaged apical process of aedeagus, we nonetheless identified the Japanese specimen as Ps. taiwanensis . The female morphology is not informative for distinguishing this species from Ps. crenulicauda and other relatives.

Figures

FIGURE 1. Habitus of Pseudatheta spp. A. Pseudatheta crenulicauda (Bernhauer, 1907), comb. nov.; B. Pseudatheta taiwanensis Pace, 2008; C. Pseudatheta hilaris (Sharp, 1888), comb. nov., lectotype of Oxypoda hiralis; D. Pseudatheta thailandensis Pace, 1992; E. Pseudatheta cooteri Pace, 1998; F. Pseudatheta elegans Cameron, 1920. Scale bars: 1.0 mm.

FIGURE 4. Pseudatheta taiwanensis Pace, 2008. A. male elytra (white arrow indicates granules); B. male tergite VII (white arrow indicates granule); C. male sternite VI (white arrow indicates medial lobe).

FIGURE 5. Pseudatheta spp. A–C: Pseudatheta crenulicauda (Bernhauer, 1907), comb. nov., D–F: Pseudatheta taiwanensis Pace, 2008. A, D. male tergite VIII in dorsal view; B, E. median lobe of aedeagus in lateral view; C, F. spermatheca. Scale bars: 0.1 mm.