Lathrobium fukuense Y. Sato, 2023

Sato, Yuya, 2023, Two new species of the genus Lathrobium (Coleoptera: Staphylinidae: Paederinae) from Gotô Islands, Japan, Zootaxa 5254 (2), pp. 278-286 : 281-285

publication ID	https://doi.org/ 10.11646/zootaxa.5254.2.7
publication LSID	lsid:zoobank.org:pub:127BD26D-3150-46EB-8FEB-ECA338F17D63
DOI	https://doi.org/10.5281/zenodo.7733407
persistent identifier	https://treatment.plazi.org/id/03BAF273-385C-FFF3-E189-3D8E4D6C77B6
treatment provided by	Plazi
scientific name	Lathrobium fukuense Y. Sato
status	sp. nov.

Treatment

Lathrobium fukuense Y. Sato sp. nov.

( Figs. 3 View FIGURE 3 , 4 View FIGURE 4 , 5 View FIGURE 5 )

[Japanese name: Fukue-hime-kobane-naga-hanekakushi]

Type series. Holotype: male, Japan: Kyushu , “ JAPAN: Nagasaki-ken / Goto-shi / Nanadake Shirine / 10. X. 2022. / Y. Sato & T. Hashizume” (KUM) . Paratype: 2 males, 1 female, same data as holotype (KUM) ; 2 males, 1 female, “ JAPAN: Nagasaki-ken / Goto-shi / Nanatsudake Trail Entrance Park / 10. X. 2022. / Y. Sato & T. Hashizume” (KUM) .

Description. BL = 5.5–7.3 mm, FBL = 2.4–2.9 mm (n = 7) Coloration: Body ( Fig. 3–A View FIGURE 3 ) brownish black, moderately shining, with frons, labrum, mandible reddish brown; antennae, maxillary palpi, legs orangish brown; elytra reddish black but sutural reddish brown; abdomen reddish brown; posterior margin of tergite VII and VIII brownish red; tergite IX and X brownish yellow.

Head slightly transverse with HW/HL = 1.14, widest at the basal 1/4 of head; frontal area flattened; surface coarsely and punctate, punctations sparser on frons and vertex, gradually becoming denser toward posterior and lateral margins, with dark brown setae. Eyes small and slightly protruding; longitudinal diameter about 1/3 as long as temple in dorsal view. Antennae elongate, AL/HL = 2.31; antennomere 1 slightly robust and widest at the middle point; antennomeres 2 and 3 slightly oblong; antennomeres 4–10 nearly circle; antennomere 11 fusiform; relative length of antennomeres as follows: 20.68: 12.71: 12.20: 12.20: 10.00: 10.00: 10.17: 10.00: 10.00: 10.00: 15.42; relative maximum width of antennomeres as follows: 16.56: 11.88: 11.88: 10.00: 10.00: 10.00: 10.00: 10.00: 10.00: 10.00: 12.50.

Pronotum oblong, PL/PW = 1.22, PL/HL = 1.47, PW/HW = 1.05; widest at apical 1/5; lateral sides of pronotum almost straight, feebly 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 black setae.

Scutellum shield with some punctations and both anterior and posterior scutellar ridges. Elytra subtrapezoidal and widened posteriorly, EW/EL = 1.69, EL/PL = 0.52, EW/PW = 1.09; lateral side almost straight; posterior corners rounded; disc covered with sparse and coarse punctations, gently shining; punctations denser than on pronotum, with brownish black setae. Hind wing completely reduced. Legs shortened; tibiae and tarsi clothed with golden setae, tarsomeres 1–4 of protarsus dilated.

Abdomen elongate, gradually dilated from segment III–V, thence contracted to the posterior end; each tergite covered with minute punctations and dark brown setae, clothed distinctly long setae on each side near posterior margin; tergite X as long as posterolateral processes of tergite IX.

Male. Sternite VII ( Fig. 3–B View FIGURE 3 ) transverse, with a shallow depression at posteromedian area; posterior margin almost straight; several setae at posteromedian area grown toward interior; sternite VIII ( Fig. 3–C View FIGURE 3 ) elongate, without posteromedian impression; posterior margin rounded, with long setae; sternite IX elongate.

Aedeagus ( Figs. 4–A, B, C View FIGURE 4 ) 1. 53 mm long, elongate; ventral process conspicuously long and slender, well sclerotized and nearly symmetrical, with one weak ridge at median area from apical 1/3 to apex; apex of ventral process gently rounded; each lateral side of ventral process concave at apical 1/3, curved ventrally from 1/2 to apex; the part above basal foremen rounded, with two projections at antero-lateral side; dorsal plate sclerotized and slender, widest at basal 1/4, gradually dilated to widest point at basal 1/4, thus contracted toward acute apex; middle area remarkably widen, with small hook in apex, curved dorsally from 1/2 to apex; apical part slightly curved right side in dorsal view; internal sac including about 20 sclerotized spines; sclerotized spines as thin triangles, forming two lines vertically; patch of several spines at apex.

Female. Sternite VIII ( Fig. 1–D View FIGURE 1 ) elongate, densely fringed with numerous setae.

Diagnosis. This new species is similar to Lathrobium horridum Assing, 2013 , which is described from Mt. Houman-zan, Fukuoka Pref. and belongs to the Lathrobium brachypterum group ( Senda 2020), in the general appearance and the aedeagal structure. However, the new species can be distinguished from it by the following characteristics: 1) internal sac with many sclerotized spines; 2) relatively smaller BL (5.5–7.3 mm); 3) sternite VIII without posteromedian impression; 4) each lateral side of ventral process of aedeagus with concavity at apical 1/3; 5) dorsal plate of aedeagus widened at middle area (while in L. horridum: BL = 6.7–8.0 mm; sternite VIII with a shallow posteromedian impression; each lateral side of ventral process of aedeagus straight; dorsal plate of aedeagus slender; internal sac without sclerotized structures).

Etymology. The specific name of new species is derived from the type locality, “Fukue-jima”.

Distribution. Japan (Fukue-jima, Gotô Islands, north of Kyushu).

Habitat. All specimens were corrected under leaf litter.