Ectamenogonus matobai (Kishii, 1973)

(Figures 1A, 3, 4)

Penthelater matobai Kishii, 1973: 12 (original description; type locality: Japan, Okinawa Prefecture, Ishigaki City ( Ishigaki Island)).

Ectamenogonus matobai (Kishii, 1973); Kishii, 1999: 56 (change generic status) [partim].

Type material. Holotype. Female [5636], Japan, Okinawa Prefecture, Ishigaki City ( Ishigaki Island), 14 VI 1971, Isao Matoba leg. Verbatim label data (Fig. 4A). “ HOLOTYPE ”; “ ♀ ”; “5636”; “ISHIGAKI City/ Ishigaki Is./ 14- VII-1971 / Leg. I. Matoba ”; “ Penthelater / matobai/ Kishii (Ms)/ Det. T. KISHII. 1972”.

Female. Diagnosis. Antennomere IV 1.3 x longer than II– III combined. Prothorax 1.2 x longer than wide. Posterior edge of scutellar shield almost truncate but slight emarginate medially. Elytra 2.2 x longer than wide, 1.8 x longer than pronotum length. Spiculum ventrale 2.5 x longer than sternite VIII. Ovipositor 0.9 x longer than length of midline of abdominal ventrites. Bursa copulatrix 2.1 x length of uterus, with two clusters of sclerotized spines.

Measurements. BL: 12.9, BW: 3.79, MAE: 2.14, MBE: 1.32; OI: 162, PL: 4.44, PML: 3.72, PW: 3.79, PI: 117, EL: 8.10, EW: 3.65, EI: 222, BI: 183.

Redescription. Body widest near pronotum hind angles; surface with microstructures; interspaces between punctures generally as long as puncture diameter but partly smaller than puncture diameter; frons, hypomeron, scutellar shield and abdomen interspaces between punctures larger than puncture diameter (Fig. 3A, B, G, H). Color. Body brown (Fig. 1A). Labrum red-brown (Fig. 3C). Antennae orange (Fig. 1A). Mandible red-brown (Fig. 3C). Maxillary palpomeres orange (Fig. 3C). Prosternum and hypomeron red-brown (Fig. 3A). Elytra around striae blackish (Fig. 1A). Legs orange (Fig. 3A). Abdomen becoming paler apicad (Fig. 3A). Tergites and sternites VIII red-brown (Fig. 4C). Body covered with orange to red-brown setae (Figs. 1A, 3A).

Head. Frons beyond eyes 0.3 x longer than wide (Fig. 3B); supra-antennal carina in ventral view weakly emarginate but almost straight medially (Fig. 3C). Antennae not reaching pronotum posterior margin excluding posterior angles by apical antennomere (Fig. 1A); II 1.1 x longer than wide; III 1.2 x longer than wide; IV 2.2 x longer than wide, 1.3 x longer than II–III combined (Fig. 3D), 1.1 x longer than V; V 1.9 x longer than wide; XI 2.7 x longer than wide (Fig. 3E).

Prothorax 1.2 x longer than wide, widening posteriad, widest behind hind angles (Fig. 1A); sides rounded in anterior half, straight in posterior half. Pronotum without median longitudinal depression. Prosternum: ventral margin roundly inclined in anterior 1/3 (Fig. 3F); anterior lobe just reaching anterior angles of prothorax (Fig. 3F). Prosternal process without depression between procoxae (Fig. 3H); side of dorsal lobe widening posteriad, widest near anterior half and then concavely narrowed (Fig. 3A); ventral margin of ventral lobe in profile straightly inclined and then broadly convex in posterior half (Fig. 3F); apex in ventral and lateral views rounded (Fig. 3A, F). Hypomeron slightly grooved next to impunctate ridge (Fig. 3H: white arrow); posterior margin with angle near mesial projection (Fig. 3H: black arrow). Pronotosternal sutures moderately opened anteriorly (Fig. 3H). Scutellar shield 1.6 x longer than wide (Fig. 3G), widest near anterior half, convex, strongly inclined anterior-downwards, not visible in profile (Fig. 3F); anterior edge broadly rounded; sides broadly rounded anteriorly; posterior edge almost truncate but slight emarginate medially (Fig. 3G: arrow). Mesosternum: posterior edge 0.1 x wider than mesosternum width, triangularly emarginate (Fig. 3I: arrow), with widely rounded angles; borders of mesosternal cavity in profile horizontal and then abruptly inclined (Fig. 3F). Elytra 2.2 x longer than wide, 1.8 x longer than pronotum length; apex emarginate; apical outer edge of each elytron rounded; apical internal edges of each elytron slightly pointed or rounded (likely due to damage) (Fig. 3J).

Abdomen. Ventrite V 0.6 x longer than wide (Fig. 3A). Tergite VIII 1.3 x longer than wide (Fig. 4D). Sternite VIII 1.0 x longer than wide (Fig. 4E); spiculum ventrale 2.5 x longer than sternite VIII (Fig. 4C). Ovipositor 0.9 x longer than length of midline of abdominal ventrites; coxites two segmented at ventral side (Fig. 4H; indistinct due to press of glass), with some setae; stylus with setae around apex (Fig. 4G). Vagina long; uterus globular (Fig. 4C); bursa copulatrix U-shaped, long, 2.1 x length of uterus, with 78 sclerotized spines, of which 29 spines forming cluster in first half and 49 spines forming rows in latter half (Fig. 4F); long thin sac extending from apex of bursa copulatrix (Fig. 4C), with coiled sac near apex of bursa copulatrix (Fig. 4F).

Male. Unknown.

Comparative notes. Ectamenogonus matobai is distinguished from the Japanese congeners by the robust body (the other species in parentheses): elytra>2.3 x longer than wide, EI: 222 (elytra <2.3 x longer than wide, EI: 235– 260); elytra>1.9 x length of pronotum, BI: 182 (elytra <1.9 x length of pronotum, BI: 191–255); spiculum ventrale 2.5 x longer than sternite VIII (spiculum ventrale 3.6–4.1 x longer than sternite VIII); ovipositor 0.9 x longer than length of midline of abdominal ventrites (ovipositor 1.2–1.3 x longer than length of midline of abdominal ventrites).

Distribution (Fig. 20B). Japan: Yaeyama Islands of the Ryukyu Islands (Ishigaki Island). Taiwan (Schimmel, 2003).

Kishii (1999) included the Kume, Ishigaki, and Iriomote Islands in the range of E. matobai . Kishii (2004a) stated that the species from Kume and Ishigaki islands is not E. matobai, but he did not give detailed information on the specimens mentioned; this study did not find the specimens that were evidence of the distribution in Kishii (1999, 2004a). In this study, E. matobai is treated to be only from the holotype from Ishigaki Island, and the species from Kume Island was determined to be E. plebejus (see discussion of E. plebejus).

Ecology. There is no ecological information.