Lathrobium satoi Watanabe, 2003

Senda, Yoshihiro, 2024, Seven new species of the genus Lathrobium Gravenhorst (Coleoptera: Staphylinidae: Paederinae) from Central Honshu, Japan, with new distributional records, Zootaxa 5403 (5), pp. 501-529 : 520-522

Lathrobium satoi Watanabe, 2003

( Figs. 11 , 12 )

Lathrobium satoi Watanabe, 2003: 151 [original description].— Assing, 2013: 1638 [listed].— Schülke & Smetana, 2015: 956 [catalogued].— Assing, 2019: 104 [listed].

Type material. Not examined.

Material examined. JAPAN: Honshu: [Aichi Pref.] 8♂♂, 1♀ (1 ♂ slightly teneral), Mennoki-tôge, 20.IX.1978, M. Satô leg. (EUMJ) ; 2♂♂, 1♀, same locality, but 10.VIII.2020, T. Ôno leg. (pcYS) ; 4♂♂, 2♀♀, ditto, but 12.IX.2020 (pcYS) ; 2♀♀, ditto, but 14.IX.2020 (pcYS) ; 3♂♂, 2♀♀, Takadoya, Otagi-chô, Toyota-shi , 28.IV.2022, T. Ôno leg. (pcYS) ; 2♂♂, 4♀♀, Dando-uradani, Shitara-chô , 20.IX.1978, M. Satô leg. (EUMJ) .

Redescription. For a detailed description including male genital organs, see Watanabe (2003).

Male. Dorsal habitus as shown in Fig. 11A . Length/width ratio of each antennomere I to XI as follows: 2.7, 1.7, 1.4, 1.4, 1.4, 1.4, 1.3, 1.3, 1.3, 1.3, 2.3; relative lengths of antennomeres from base to apex: 25.8: 12.5: 11.9: 11.1: 11.1: 10.8: 10.0: 10.0: 10.0: 10.0: 16.1, and relative widths: 14.0: 10.8: 12.4: 11.2: 11.2: 11.2: 11.2: 11.2: 11.2: 11.2: 10.0. HL/HW ≈ 1.0; AL/FBL ≈ 0.6; PL/PW ≈ 1.2; PL/HL ≈ 1.4; PW/HW ≈ 1.1; EL/EW ≈ 0.8; EL/PL ≈ 0.8; EW/PW ≈ 1.1.

Abdominal sternites VI–VIII as shown in Fig. 11B .

Aedeagus as shown in Fig. 11C–E . Endophallus ( Fig. 11F & G ): internal sac slightly longer than dorsal plate, simple, symmetric, but weakly curved to right, without any membranous projection in everted condition, with ventrolateral teeth patch as Fig. 11F ; sclerotised copulatory piece lacking, but with numerous minute sclerites on dorsal side of apex.

Female. Length/width ratio of each antennomere I to XI as follows: 2.5, 1.2, 1.2, 1.2, 1.2, 1.4, 1.3, 1.3, 1.4, 1.3, 2.3; relative lengths of antennomeres from base to apex: 30.0: 12.0: 12.0: 11.0: 11.0: 11.0: 10.0: 10.0: 11.0: 12.0: 18.0, and relative widths: 15.0: 12.5: 12.5: 11.3: 11.3: 10.0: 10.0: 10.0: 10.0: 11.3: 10.0. HL/HW ≈ 1.0; AL/FBL ≈ 0.6; PL/PW ≈ 1.2; PL/HL ≈ 1.4; PW/HW ≈ 1.1; EL/EW ≈ 0.8; EL/PL ≈ 0.8; EW/PW ≈ 1.1.

Tergum VIII feebly emarginate at middle of posterior margin ( Fig. 11H ); sternite VIII ( Fig. 11I ) projected apically, slightly truncate at middle of posterior margin, which is fringed with micropubescence; tergum IX ( Fig. 11H & I ) similar to male, but with large triangular flap-like ventral plate on base; tergum X ( Fig. 11H ) similar to male. Gonocoxites ( Fig. 11I ): lateral gonocoxal plate (distal and proximal gonocoxites fused) elongate, setigerous, with few setae in apical area, with rounded apex.

Measurements. Male (n = 12)—BL: 7.32–7.85 mm (7.55± 0.20 mm); FBL: 3.12–3.32 mm (3.21± 0.06 mm); HL: 0.91–0.97 mm (0.94± 0.02 mm); HW: 0.95–1.01 mm (0.97± 0.02 mm); AL: 1.80–1.88 mm (1.85± 0.02 mm); PL: 1.22–1.35 mm (1.29± 0.04 mm); PW: 1.03–1.12 mm (1.08± 0.03 mm); ELL: 0.95–1.03 mm (0.98± 0.02 mm); ELW: 1.13–1.21 mm (1.17± 0.03 mm).

Female (n = 3)—BL: 7.14–7.26 mm (7.19± 0.06 mm); FBL: 2.96–3.05 mm (3.01± 0.04 mm); HL: 0.87–0.90 mm (0.89± 0.02 mm); HW: 0.88–0.90 mm (0.89± 0.01 mm); AL: 1.63–1.72 mm (1.69± 0.05 mm); PL: 1.19–1.22 mm (1.21± 0.02 mm); PW: 0.98–1.01 mm (1.00± 0.02 mm); EL: 0.90–0.92 mm (0.91± 0.01 mm); EW: 1.08–1.17 mm (1.13± 0.05 mm).

Only individuals collected in the type locality were measured.

Distribution. Japan: Central Honshu (Aichi Prefecture) ( Fig. 12 ).

Comments. This species was originally described from “near Mennoki-tôge, Irabu-chô” (probably misread Inabu-chô, now Toyota-shi), Aichi ( Watanabe, 2003) and was previously known only from the type locality.

Figures

FIGURE 11. Lathrobium satoi Watanabe. male (A–G) and female (H–I): dorsal habitus (A); apical part of abdominal sternites (B, I); aedeagus, ventral view (C); ditto, lateral view (D); ditto, dorsal view (E); inverted endophallus of aedeagus, ventral view (F); ditto, lateral view (G); apical part of abdominal terga (H). Scale bars = 1.0 mm for A, 0.5 mm for B–I.

FIGURE 12. Geographical distribution of Lathrobium kawamurai sp. nov., L. volkeri sp. nov., L. satoi Watanabe and their related congeners in central Honshu, Japan.