Lathrobium gotoianum Y. Sato sp. nov. (Figs. 1, 2, 5) [Japanese name: Gotô-kobane-naga-hanekakushi] Type series. Holotype: male, Japan: Kyushu, “Mt Sannou-zan / Goto-Islands / Nagasaki Pref / 29. vi. 1996 / S. Nomura leg” (KUM). Paratype: 1 male, 1 female, same data as holotype (KUM); 2 females, “ Goto-Islands / Mt. Gonegen [probably Mt. Gongen] / Nagasaki Pref / 28. vi. 1996 / S. Nomura leg.” (KUM); 1 female, “ Oosezaki / Goto Islands / Nagasaki Pref / 25. vi. 1996 / S. Nomura leg.” (KUM); 1 female, “ Tamano-ura / Goto Islands / Nagasaki Pref / 25. vi. 1996 / S. Nomura leg.” (KUM); 1 male, 1 female, “ VIII. 15. 1977. / Kamigoto / Nagasaki / Nakadori-jima / Mt. Tanna / Oishi” (KUM); 1 female, “ VIII. 15. 1977. / Nakadori-jima / Nagasaki / Kamigoto / Mt. Sannou-zan / Oishi” (KUM); 1 male, 1 female “ JAPAN: Nagasaki-ken / Goto-shi / Nanadake Shirine / 10. X. 2022. / Y. Sato ” (KUM). Description. BL = 8.9–10.7 mm, FBL = 3.7–4.0 mm (n = 6). Coloration: Body (Fig. 1–A) brownish black, moderately shining, with frons, labrum, mandible, antennae reddish brown; maxillary palpi, legs brownish light red; elytra reddish black but sutural reddish brown; abdomen reddish brown, posterior margin of tergite VII and VIII brownish light red; tergite IX and X brownish yellow. Head slightly longer length than width, HW/HL = 0.98, widest at the basal 1/3 of head; frontal area flattened; surface coarsely and punctate; punctation sparser on frons and vertex, becoming denser toward posterior and lateral margins, with dark brown setae. Eyes small and slightly protruding; longitudinal diameter about 1/5 as long as temple in dorsal view. Antennae elongate, AL/HL = 1.95; antennomere 1 robust and widest at apical 1/4; antennomere 2 slightly elongated and shorter than antennomere 3; antennomeres 3–10 narrow at base and widening towards apex; antennomere 11 fusiform; relative length of antennomeres as follows: 20.91: 10.36: 11.82: 10.73: 10.91: 10.18: 10.73: 10.00: 10.00: 10.00: 12.73; relative maximum width of antennomeres as follows: 15.40: 10.40: 10.60: 10.00: 10.20: 12.00: 11.60: 11.60: 11.60: 10.60: 10.00. Pronotum subtrapezoidal, with anterior margin wider than posterior one, PL/PW = 1.17, PL/HL = 1.06, PW/HW = 0.92, widest at apical 1/5; lateral sides of pronotum gently dilated to widest point, thence gradually convergent toward posterior margin; all corners obtusely rounded; disc sparsely covered with coarse and weak punctations except medial longitudinal line; punctations slightly sparser and less than head, with brownish yellow setae. Scutellum with some punctations and both anterior and posterior scutellar ridges. Elytra subtrapezoidal and widened posteriorly, EW/EL = 1.63, EL/PL = 0.52, EW/PW = 1.00; lateral margins almost straight; posterior corners rounded; disc covered with sparse and coarse punctations, gently shining; punctations denser than on pronotum, with brownish yellow setae. Hind wing completely reduced. Legs shortened tibiae and tarsi with golden setae; tarsomeres 1–4 of protarsus dilated. Abdomen elongate, gradually widened from segment III–V, thence contracted to the posterior end; each tergite covered with micropunctations and dark brown setae, distinctly long setae on each side near anterior margin; tergite X as long as posterolateral processes of tergite IX. Male. sternite VII (Fig. 1–B) transverse, without posteromedian impression, posterior margin almost straight; sternite VIII (Fig. 1–C) without posteromedian impression; each post–lateral margin slightly concave, with sparse, short thick setae on posteromedian area; sternite IX elongate. Aedeagus (Figs. 2–A, B, C) 1.74 mm long, elongate oval shape; ventral process well sclerotized and nearly symmetrical; basal and middle part of ventral process thicker than apex in lateral view; nearly pentagonal part above basal foramen; apical part of ventral process rounded and bulged, with small concave on anterior margin of bulge; dorsal plate sclerotized, widest at apical 1/5, gradually widened to the widest point at apical 1/5, thus contracted toward acute apex; internal sac composed of large sac and two sclerotized structures; lateral area of sac with scalelike spines; median area reticulate; one sclerotized structure elongate, apical part longer than that of ventral process; other shortened, curved toward right side in ventral view. Female. Sternite VIII (Fig. 1–D) elongate, densely fringed with numerous setae, each post-lateral margin slightly concave. Diagnosis. This new species is similar to Lathrobium onodai Watanabe, 1996, which is described from Shimokoshiki-jima, Kagoshima Pref., in the general appearance and the aedeagal shape. However, the new species can be easily distinguished from it by the combination of following characteristics: 1) large internal sac with sclerotized structures; 2) head slightly oblong (HW/HL = 0.98) and broader than pronotum; 3) postrior margin of sternite VIII without distinct impression in male; 4) apical part of ventral process with small concave; 5) dorsal plate of aedeagus without hook curving dorsally (while in L. onodai: head slightly transverse; anterior margin of sternite VIII with shallow impression; internal sac of aedeagus without scale-like spines; apical part of ventral process with hook curving ventrally; dorsal plate of aedeagus with hook curving dorsally). Etymology. The specific name of new species is derived from the type locality, “Gotô Islands”. Distribution. Japan (Gotô Islands, north of Kyushu). Habitat. All specimens were corrected under leaf litter.

Published as part of Sato, Yuya, 2023, Two new species of the genus Lathrobium (Coleoptera: Staphylinidae: Paederinae) from Gotô Islands, Japan, pp. 278-286 in Zootaxa 5254 (2) on pages 279-281, DOI: 10.11646/zootaxa.5254.2.7, http://zenodo.org/record/7727487