Psammoecus omotoensis, Yoshida, Takahiro & Hirowatari, Toshiya, 2014

Yoshida, Takahiro & Hirowatari, Toshiya, 2014, A revision of Japanese species of the genus Psammoecus Latreille (Coleoptera, Silvanidae), ZooKeys 403, pp. 15-45 : 32-33

Psammoecus omotoensis sp. n. Figs 2B, 9and 14 G–I

Diagnosis.

This species is similar to Psammoecus trimaculatus and other species closely similar to Psammoecus trimaculatus . However, it can be distinguished from them by the male genital structure, especially the parameres which are fused to the phallobase. The distinguishing external characters of this species are tooth IV of the lateral margins of pronotum extended in a posterolateral direction and the long antennae, especially the 1st antennomere.

Description.

Body length. 2.71-2.77 mm (n=2).

Coloration (Fig. 2B). Head and pronotum yellowish-brown to reddish-brown. Elytra yellowish-brown with dark maculae, round ones at half of each elytron, black ones on posterior half of elytral suture narrower toward posterior elytral suture, a thin short black band between these maculae. Antennae yellowish-brown, almost unicolorous, 11th (apical) antennomere comparatively bright.

Head (Fig. 9A, B, C). Transverse, HW/HL 1.59-1.63; IE/HL 1.07. Temples well enlarged behind eyes, narrowed at bases. Eyes small, moderately rounded. Frequent pubescence and very sparse punctuation on ventral surface, moderately dense punctuation on dorsal surface. Antennae 1.44-1.49 mm long; covered with frequent medium length semi-erect fine setae and some long erect setae on each antennomere; approximate ratio of holotype as follows: 2.6: 1.0: 1.2: 1.4: 1.4: 1.4: 1.3: 1.1: 1.2: 1.0: 1.9 (Fig. 9A).

Pronotum (Fig. 9B, C). Transverse, PW/PL 1.30-1.35. Punctuation on dorsal surface coarse. Pubescence composed of short fine setae, a long seta on each tooth on lateral margins and anterior and posterior angles. Each anterior angle with several very small prominences and two small teeth, each lateral margin with four teeth; tooth I comparatively small, teeth II and III almost the same size, longer than tooth I, tooth IV extended in posterolateral direction, longer than tooth II and III, each posterior angle with a very small protuberance.

Elytra (Fig. 9E). Oval, EW/BL 0.37-0.44. Around half of lateral margins relatively expanded. Rows of punctures wider than interstices. Pubescence composed of medium length semi-erect setae and a few long setae around anterolateral margins.

9th abdominal sternite (Fig. 14G) Strut Y-shaped, anterior 2/7 slightly thickened, cut from anterior 2/7, diverging in posterior 1/3, branches long, ends of each branch curved inwards. Lateral sclerites elongate, membranous.

Aedeagus (Figs 14H and I) Parameres fused with phallobase, incised shallowly at inner and lateral margins of bases, relatively stout, gradually curved inwards, three long setae around posterior 1/3, some short setae on posterior half, well punctuated on anterior half of inner margins. Phallobase broad and somewhat flat, anterior margin widely but shallowly incised, lateral margins slightly depressed around anterior 1/4. Penis wide, thinner toward apex, narrowed around apex, punctuated around apex, densely punctuated at apex.

Type series.

Holotype: male, Mt. Omoto-san, Ishigaki Island, Okinawa Prefecture, Japan, 23 –III– 2000, T. Kurihara leg. (EUMJ). Paratype: [Okinawa Pref.] 1 male, same data as holotype, T. Kurihara leg. (EUMJ).

Distribution.

JAPAN: Ishigaki Island.

Etymology.

The specific name is derived from the type locality of the new species, Mt. omoto-san, Ishigaki Island, Okinawa Prefecture.