Psammoecus quadrimaculatus Reitter, 1874

Yoshida, Takahiro & Hirowatari, Toshiya, 2014, A revision of Japanese species of the genus Psammoecus Latreille (Coleoptera, Silvanidae), ZooKeys 403, pp. 15-45 : 37-39

Psammoecus quadrimaculatus Reitter, 1874 Figs 2F, 12and 14 P–R

Psamoecus [sic.] quadrimaculatus Reitter, 1874: 525. Type locality: Japan; Type deposition: the Natural History Museum, London; Type examined. (misspelling)

Diagnosis.

This species is similar to Psammoecus trimaculatus , Psammoecus triguttatus and Psammoecus labyrinthicus sp. n., but can be distinguished from Psammoecus trimaculatus and Psammoecus triguttatus by the wide triangular basal portion of the parameres and the apically narrow portion of the penis, and from Psammoecus labyrinthicus sp. n. by the longer parameres, the apically narrow portion of the penis and the shape of the phallobase.

Description.

Body length. 2.50 mm (n=1).

Coloration (Fig. 2F). Head reddish-brown, pronotum somewhat light reddish-brown. Elytra blackish-brown with four large yellowish-brown maculae; macula around anterior 1/4 of each elytron almost quadrate, macula on posterior half longer than wide. Antennae yellowish-brown basally, 6th to 10th antennomeres black, 6th slightly brighter, 11th (apex) bright.

Head (Figs 12A, B and C). Rounded-triangular, HW/HL 1.68; IE/HL 1.09. Temples slightly expanded behind eyes, narrowed at base. Eyes large, prominent, diameter about half of length of head. Punctuation of dorsal surface moderately dense, on ventral surface sparse, and absent on center portion of ventral surface. Antennae 1.44 mm; covered with medium length pubescence and some relatively long erect setae on each antennomere; approximate ratio of holotype as follows: 2.4: 1.0: 1.0: 1.1: 1.1: 1.3: 1.0: 1.1: 1.2: 1.1: 2.2 (Fig. 12A).

Pronotum (Fig. 12B, C). Roundly subquadrate, PW/PL 1.34. Punctuation on dorsal surface relatively strong and moderately sparse. Pubescence composed of medium length setae, a long seta on each tooth on lateral margins and anterior angles, a relatively long seta on each posterior angle. Each anterior angle with several small teeth, each lateral margin with four short teeth; tooth I small, tooth II longer than tooth I, teeth III and IV almost same size, longer than tooth II, teeth II, III and IV relatively widened around base, each posterior angle with a few very small teeth.

Elytra (Fig. 12E). Elongate-oval, EW/BL 0.46. Rows of punctures wider than interstices. Pubescence composed of many medium length semi-erect setae, long erect setae in a row on lateral margins.

9th abdominal sternite (Fig. 14P). Strut cut at anterior 1/3, diverging deeply around posterior 1/3. Lateral sclerites rhomboid, comparatively large, curved inwardly.

Aedeagus (Fig. 14Q, R). Parameres club-shaped; narrow portions relatively broad, punctuated sparsely, with several sparse setae, apex with a long seta; wide portions punctuated densely on posterior half of inner margins and anterolateral portions of outer margins, posterior half of inner margins with many setae. Phallobase consisting of two layers, posterior margin incised roundly, distance between posterior margin and deepest point of incision of margin of upper layer narrow, anterior margin of lower layer relatively narrowly incised, protuberances around anterior 1/4 narrow, projecting inwards, posterior margin of lower layer broadly incised. Penis relatively elongate and flat, with relatively dense punctuation on posterior 1/8.

Type series.

Holotype: male, Nagasaki, Nagasaki Prefecture, Japan, 1869, G. Lewis leg. (BMNH).

Distribution.

JAPAN: Nagasaki?.

Remarks.

Type specimen was mounted with a label reading 'Nagasaki | 1869 |? imported in Rice –’. We have not been able to find any specimen of this species from Japan other than holotype. Hence, occurrence of this species in Japan seems to be questionable.