Psammoecus scitus, 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 : 17-21

Psammoecus scitus sp. n. Figs 1A, 3and 13 A–C

Psammoecus quadrimaculatus : Hirano 2009: 64, 65, 82, fig. 4. - Hirano 2010: 12, 14. (misidentification)

Diagnosis.

This species is similar to Psammoecus hiranoi Yoshida & Hirowatari, 2013, especially in darker specimens. However they can be distinguished by the ventral shape of the head. The temples of this species are immediately narrowed behind eyes, while those of Psammoecus hiranoi are widened behind the eyes and gradually narrowed toward the anterior margins.

Description.

Body length. 2.65-3.26 mm (n=48).

Coloration (Fig. 1A). Head and pronotum yellowish-brown to reddish-brown. Elytra black with yellowish-brown maculae; horizontal band at anterior 1/4, sometimes enlarged toward bases of elytra, round maculae at posterior 1/4, connected to lateral margins. Antennae yellowish-brown basally, 6th antennomere darker, 7th to 10th blackish-brown, 11th (apex) very bright.

Head (Fig. 3A, B, C). Broad, HW/HL 1.31-2.00; IE/HL 0.87-1.30. Temples immediately narrowed behind eyes, slightly incised at bases. Dorsal surface with comparatively coarse punctuation, ventral surface with very sparse punctures. Antennae 1.40-1.43 mm long, slender; covered relatively sparsely with long erect pubescence on each antennomere; approximate ratio of antennomeres of holotype as follows: 2.5: 1.1: 1.2: 1.3: 1.3: 1.3: 1.1: 1.2: 1.2: 1.0: 2.0 (Fig. 3A).

Pronotum (Figs 3B, C). Subquadrate, PW/PL 1.14-1.32. Punctuation on dorsal surface comparatively sparse, punctuation on ventral surface sparser than on dorsal surface. Pubescence composed of many short setae, and long setae on teeth on lateral margins and anterior and posterior angles. Anterior angles with a few very small protrusions, lateral margins with several small teeth, these teeth variable, slightly longer on lateral margins around anterior and posterior angles, and each posterior angle with very small teeth.

Elytra (Fig. 3E). Elongate-oval, EW/BL 0.38-0.51. Rows of punctures narrower than interstices. Pubescence composed of many semi-long medium length setae, and some long erect setae in a row around lateral margins, longer toward anterior portion.

9th abdominal sternite (Fig. 13A). Strut very long, narrow, cut at anterior 3/8, diverging gradually at posterior 1/8, branches comparatively small. Lateral sclerites elongate with small sclerites attached around posterior apical portion.

Aedeagus (Fig. 13B, C). Parameres broad, depressed at base, narrowed on inner margins in posterior half, incised around apex, punctuated very sparsely, a few long setae around apex, several short setae on lateral margins and posterior half of inner margins. Phallobase diverging in anterior half, each branch twisted at anterior 1/4. Penis relatively elongate, curved dorsally before apex.

Type series.

Holotype: male, Kûra, Ishigaki Island, Okinawa Prefecture, Japan, 22 –IX– 2012, T. Yoshida leg. (EUMJ). Paratypes: [Kagoshima Pref.] 1 ex., Honcha, Amami-Ôshima Island, 23 –VII– 1962, N. Ohbayashi leg. (EUMJ); 1 ex., Nadakawa, Amami-Ôshima Island, 16 –VII– 1962, N. Ohbayashi leg. (EUMJ); 1 ex., Kamiya, Amami-Ôshima Island, 4 –XI– 1984, M. Tomokuni leg. (EUMJ). [Okinawa Pref.] 1 ex., Hiji, Kunigami Village, Okinawa Island, 15 –20–VI– 1994, K. Okada leg. (EUMJ); 1 male & 1 female, Takazato, Kunigami Village, Okinawa Island, 18 –22–VI– 2003, I. Tanaka leg. (ITC); 2 exs., Inamine, Nago City, Okinawa Island, 26 –IX– 2012, T. Yoshida leg. (ELKU); 1 ex., Shokubutsuen, Miyako Island, 3 –III– 1999, T. Mizoguchi leg. (EUMJ); 1 female, Kûra, Ishigaki Island, 22 –IX– 2012, T. Yoshida leg. (ELKU); 4 exs., Ôura Dam, Ishigaki Island, 7 –X– 2013, R. Itô leg. (ELKU); 2 exs., Mt. Yarabu-dake, Ishigaki Island, 26 –III– 2000, T. Kurihara leg. (EUMJ); 7 exs., same locality, 16 –VI– 2002, T. Watanabe leg. (ELKU); 5 exs., same locality, 8 –X– 2013, R. Itô leg. (ELKU); 1 male, same locality, 8 –III– 2006, I. Tanaka leg. (ITC); 1 female, Kabira, Ishigaki Island, 19 –IV– 2010, I. Tanaka leg. (ITC); 2 exs., Takeda Rindô, Ishigaki Island, 14 –III– 1999, T. Mizoguchi leg. (EUMJ); 2 exs., same locality, 16 –VI– 2002, T. Watanabe leg. (ELKU); 2 exs., same locality, 22 –IX– 2012, T. Yoshida leg. (ELKU); 6 exs., same locality, 23 –IX– 2012, T. Yoshida leg. (ELKU); 3 exs., Funaura, Iriomote Island, 18 –III– 2008, S. Yamamoto leg. (ELKU); 1 ex., Urauchi-gawa, Iriomote Island, 2 –VII– 1994, K. Okada leg. (EUMJ); 3 exs., Komi, Iriomote Island, 20 –III– 2008, S. Yamamoto leg. (ELKU); 1 ex., Ôtomi Rindô, Iriomote Island, 13 –III– 1999, T. Mizoguchi leg. (EUMJ); 1 ex., Mt. Inbi-dake, Yonaguni Island, 31 –III– 2009, S. Yamamoto leg. (ELKU).

Distribution.

JAPAN: Amami-Ôshima, Okinawa, Miyako, Ishigaki, Iriomote and Yonaguni Islands.

Biological notes.

This species is found in piled dead leaves such as Japanese pampas grass Miscanthus sinensis Andersson, Banana Musa sp. and some other kinds of broad-leaved tree. This species is most common in the Nansei Islands.

Etymology.

The specific name means ‘pretty’ and ‘beautiful’. This new species has vivid coloration.

Remarks.

Psammoecus scitus sp. n. has been misidentified as Psammoecus quadrimaculatus Reitter, 1874 for a long time. Psammoecus quadrimaculatus was originally described from ‘Japonia’ (=Japan) by Reitter (1874). Sato (1989) first gave the Japanese name ‘Yotsumon-semaru-hiratamushi’ to Psammoecus quadrimaculatus . Hirano (2009) and Hirano (2010) provided figures of this species as Psammoecus quadrimaculatus . However, examination of the holotype of Psammoecus quadrimaculatus deposited in BMNH revealed that external characters such as the shape of the teeth on the lateral margins of the pronotum and the male genital structure are distinctly different.