Pseudatheta cooteri Pace, 1998

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 : 38

Pseudatheta cooteri Pace, 1998

( Figs. 1E , 7A–D )

[Japanese name: Minami-hime-kinokotsuyakeshi-hanekakushi]

Pseudatheta cooteri Pace, 1998: 208 (original description;

type locality: “ China, Jiangsu Prov., Nanjing Zijinshan”): Schülke & Smetana, 2015: 634 (catalogue); Pace, 2016: 301 (Yunnan).

Material examined. JAPAN: [Kagoshima-ken]: Yaku-shima Is.: 1 male, Aiko-dake, Yakushima-chô , 25 IX–23 X 2006, T . Yamauchi et al. leg, ( KUM); 1 male, 2 females, Kurio, Yakushima-chô , 21 VII 2021, T . Hashizume leg. ( KUM); [Okinawa-ken]: Okinawa-jima Is.: 2 males, Takazato, Ôgimi-son, 3 XI 1993, M. Kimura leg. ( KUM); 2 males, Yona , 25–27 V 1974, M. Sato leg. ( KUM); Iriomote-jima Is.: 2 males, 2 females, Kampiree , 27 III 1984, S. Nomura leg. ( KUM) .

TAIWAN: 3 males, Wulai, Taipei Hsien, 17 V 1972, M, Sakai leg. ( EUM) .

Redescription. Measurements (n = 5): BL ≈ 1.65–1.84; FBL, 0.91–1.00; HL, 0.28–0.34; HW, 0.35–0.39; PL, 0.31–0.35; PW, 0.46–0.50; EL, 0.30–0.35; EW, 0.55–0.60.

Relative length of antennomeres I–XI (n = 1): 25: 27: 19: 10: 10: 10: 11: 11: 13: 13: 35. Ratio of length/width of antennomeres I–XI (n = 1): 1.94: 2.21: 1.80: 0.87: 0.66: 0.64: 0.59: 0.58: 0.63: 0.61: 1.62.

Body ( Fig. 1E ) reddish brown; head darker; elytra dark brown except for the anterior 1/4–1/3; abdominal segments V–VI darker.

Head slightly transverse, HW/HL: 1.12–1.36; 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: 1.43–1.50, PW/HW: 1.29–1.33; surface densely covered with setae, finely punctured, without microsculpture; posterior margin arcuate. Elytra wider than long, EW/EL: 1.71–1.84, EL/PL: 0.92–1.00, EW/PW: 1.13–1.24; surface densely covered with setae and finely punctured; posterior margin sinuate near posterolateral corners. Mesoventrite without longitudinal carina; mesoventral process extended to slightly beyond middle of mesocoxal cavities, with pointed apex; metaventral process shorter than mesoventral process, with rounded apex; isthmus absent.

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. Tergite VII with a tubercle on anteromedian area. Tergite VIII ( Fig. 7A ) with a tubercle on median area; six processes on posterior margin. Aedeagus as in Fig. 7C ; median lobe with large basal bulb; apical process elongated, simply curved ventrally, slightly widened at basal part; ventral process large, apex pointed, with a distinct angle on dorsa side; flagellum very long.

Female. Spermatheca ( Fig. 7D ) curved twice; distal portion large, nearly conical shape, slightly curved; median portion elongate, curved; proximal portion very small.

Distribution. Japan (Yaku-shima Is., Okinawa-jima Is., Iriomote-jima Is.), Taiwan —new record; China (Jiangsu, Yunnan).

Remarks. We report the first discovery of males of Ps. cooteri and describe them here. Variations in the shape of the ventral process of the median lobe of the aedeagus were observed ( Fig. 7B ). The aedeagus and spermatheca of Ps. spinosa , a species from Taiwan described by Pace (2008), are similar to those of Ps. cooteri . However, judging from the illustrations in that report, Ps. cooteri can be distinguished from Ps. spinosa by the longer apical process of the median lobe of its aedeagus and by the longer, weakly curved distal portion of the spermatheca. We were able to examine specimens of Pseudatheta from Taiwan and found that the aedeagi were identical to those of Ps. cooteri from Japan. We consider the former specimens to be Ps. cooteri from Taiwan, although we were unable to compare the spermathecae because females were not collected with the male specimens. While it is possible that the two species are distributed in Taiwan, the slight differences may have instead been due to intraspecific variation, deformation of the specimens, or misinterpretations in sketching. Therefore, we cannot rule out the possibility that these two species are synonyms.

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 7. Pseudatheta spp. A–D: Ps. cooteri Pace, 1998, E–G: Ps. elegans Cameron, 1920. A, E. male tergite VIII in dorsal view; B, F. median lobe of aedeagus in lateral view; D, G. spermatheca; C. ventral process of median lobe of aedeagus in lateral view, a: Yaku-shima Is., b: Iriomote-jima Is. Scale bars: 0.1 mm.