Eumorphus costatus Gorham, 1873

Yoshitomi, Hiroyuki & Sogoh, Koichi, 2019, Eumorphusmarginatus group in Sulawesi, Indonesia (Coleoptera, Endomychidae), ZooKeys 820, pp. 139-149 : 141-142

Eumorphus costatus Gorham, 1873 Figs 1A, B; 3A, B; 4A, B; 5A, B; 6 A–D

Eumorphus costatus Gorham, 1873: 34, fig. 6. Strohecker 1968: 84, figs. 11, 65 (short description and figures of habitus and male genitalia).

Material examined.

1 male and 2 females (EUMJ), "C. Sulawesi: Puncak Palopo Puncak, Indonesia, 23-25.XI.2012, Kiyoshi Ando leg."; 1 male (EUMJ), "(C. Sulawesi) Dongidongi, 10 km S of Palolo, alt. ca 1000 m, 18.VI.1986, S. Nagai leg."; 2 female (EUMJ), "INDONESIA Puncak Palopo Sulawesi Selatan 30-31.XII.1999 N. Ohbayashi leg."; 1 male & 1 female, "[INDONESIA] Bantu Kaya Angin Battang Palopo Sulawesi Selatan Alt. ca. 350 m 02°57'S, 120°08'E 31.I.2013 J. Yamasako leg."; 1 female (EUMJ), "[BONEBOLANGO: INDONESIA] Mt. Tilongkabila (Gunung Tilonkabila) N. Sulawesi, alt. ca. 1300-1500 m 0°35'18.14"N, 123°13'22.71"E - 0°35'18.37"N, 123°13'22.61"E 10.VI.2012 Ryo Ogawa leg."

Diagnosis.

This species is similar to Eumorphus marginatus Fabricius, 1801 but differs from the latter in the following characteristics: elytral spots smaller, each distant from suture by its own diameter; in E. marginatus elytral spots larger and distant from suture by 1/2 of its own diameter).

Description.

Male.

Coloration of body black, with blueish luster; elytral spots yellowish orange.

Antennae long, reaching to ca. basal 1/4 of elytra.

Pronotum (Fig. 4A) glossy, narrowly depressed in lateral parts; lateral margins subparallel-sided in basal 1/2, then gently tapered anteriorly; lateral sulci relatively long, reaching ca. basal 1/3 of PLM; anterior angles ca. 60°; posterior angles sharply pointed, projecting postero-laterally; PLM/PLS 0.85-0.86 (0.86); PWP/PWA 1.84-1.95 (1.89); PWP/PLM 1.79-1.99 (1.89); PWP/PLS 1.55-1.69 (1.62). Elytra (Fig. 1A) ovate, bluntly rounded behind, widest at middle; lateral flattened margins wide, flat dorsally; elytral spots two pairs, relatively large, each distant from suture by its own diameter; anterior ones transverse, situated in anterior 1/4 of elytra; posterior ones oval, situated in posterior 1/3 of elytra; elytra along suture (Fig. 3A) distinctly elevated in mesal part; EL/EW 1.06-1.09 (1.07); EL/PLM 4.09-4.40 (4.24); EW/PWP 2.04-2.14 (2.09); TL/EW 1.32-1.33 (1.33). Fore tibiae (Fig. 5A) stout; apical carinae distinct, covered with yellowish brown pubescence on inner surface; fore tibial tooth long, triangular, situated in apical 1/4. Metatibial apices widely prolonged and flattened, sharply pointed at outer angles.

Aedeagus (Fig. 6 A–D) 5.4 mm long; median lobe stout, expanded ventrally in median part; apical branch short, obtuse and bisinuate at apex; subapical branch long, evenly curved apically; tegmen not movable, with short tegminal strut; endophallus consisting of bifid long right membranous lobe and left membranous lobe, with rather sclerotized spinous plate at base of left lobe.

Female. Similar to male, but sexual dimorphism distinct in the following characteristics: posterior angles of pronotum (Fig. 4B) nearly right-angled; elytra with lateral flattened margins narrower than in male, gently arcuate dorsally along suture (Fig. 3B); fore tibiae (Fig. 5B) slender and straight, covered with yellowish brown pubescence in apical half; metatibial apices simple; PLM/PLS 0.80-0.84 (0.82); PWP/PWA 1.46-1.69 (1.59); PWP/PLM 1.59-1.77 (1.66); PWP/PLS 1.31-1.44 (1.37); EL/EW 1.10-1.32 (1.24); EL/PLM 3.86-4.25 (4.07); EW/PWP 1.93-2.13 (1.98); TL/EW 1.37-1.63 (1.55).

Measurements. Male (n = 2). TL 16.68-18.53 (17.61) mm; PW 5.88-6.83 (6.36) mm; PW 3.20-3.50 (3.35) mm; PL 3.28-3.43 (3.36) mm; PL 3.80-4.05 (3.93) mm; EL 13.40-15.10 (14.25) mm; EW 12.6-13.9 (13.25) mm. Female (n = 6). TL 13.40-16.85 (15.17) mm; PW 4.55-5.60 (4.96) mm; PW 2.90-3.35 (3.12) mm; PL 2.60-3.30 (2.99) mm; PL 3.20-4.00 (3.63) mm; EL 10.80-13.55 (12.18) mm; EW 8.85-10.85 (9.79) mm.

Distribution.

Indonesia (Sulawesi: South, Central, and North).