Rhinocylapus scutatus Hsiao

(Figs. 2 L, 3D, 4E, 9A–B, 13)

Rhinocylapus scutatus Hsiao 1944: 380

Rhinocylapidius scutatus: Carvalho 1955b: 221, 1957: 23; Schuh 1995: 35; Gorczyca 2006: 72

Diagnosis. Recognized by the following set of characters: spines on labrum present (Fig. 3 D); lateral margin of anterior lobe of pronotum gently carinate, with row of punctures, each bearing single, decumbent seta; scutellum flattened, with large, yellowish patch medially (Figs. 2 L, 3D); endosoma with large, distinctly curved, and twisted medially sclerite (Fig.13 A). The species is most closely related to Rh. simplicicollis in sharing similar body coloration, a flattened anterior lobe of pronotum, and non-rugose posterior lobe. It can be readily distinguished, however, by having a large, yellowish patch on the scutellum medially and by short and decumbent setae. Rh. scutatus shares a row of punctures on the lateral margin of the anterior lobe of pronotum with Rh. vittatus, but can be easily distinguished by a distinctly darker coloration of the dorsum.

Redescription. Male. COLORATION (Figs. 2 L). Dorsal surface dark castaneous. Head. Antennal segment I brown; segment II brown, with yellowish red, wide ring beyond medial part; segment III pale yellow basally, then dark yellow; segment IV dark yellow; rostrum brown. Thorax. Mesoscutum and scutellum. Scutellum with large, yellowish patch medially. Thoracic pleura. Dark brown. Hemelytron. Cuneus with inner angle yellowish red. Legs. Brownish yellow; coxa and trochanters dark brown; femur brown; tibia brown; meso- and metatibia paler, yellowish apically. Abdomen. Ranging from brown to dark brown. STRUCTURE AND VESTITURE (Fig. 2 L, 3D, 9A–B). Dorsal surface covered with fine, dark, relatively long setae. Head. Shining, covered with very sparse, fine, short setae; gula mixed with long, semidecumbent setae and with very long and protruding setae; frons slightly rugose medially; labrum with relative long, thick, flattened, protruding spines; segment II covered with sparse, semidecumbent setae, outer portion covered with very dense and short, apically curved setae, segment III sparsely covered with semidecumbent setae; segment IV covered with setae denser than those on segment III; rostrum thin, long, reaching abdomen apically. Thorax. Pronotum covered with sparse, fine setae; pronotal collar rugose, covered with fine setae; anterior lobe rather flattened, impunctate, slightly rugose, lateral margin gently carinate, with row of punctures, each bearing single, decumbent seta. Mesoscutum and scutellum. Covered with short setae, somewhat rugose. Thoracic pleura. Propleuron impunctate anteriorly. Hemelytron. Covered with relatively dense, short, decumbent, dark setae; embolium covered with setae longer than those on corium; cuneus covered with dense, relatively long setae. Legs. Femora and tibiae covered with rather short, semidecumbent setae. Abdomen. Covered with pale, reclining setae.

Male genitalia (Fig. 13). Endosoma with two sclerites: one, smaller, situated beneath second gonopore, distinctly enlarged and folded proximally, remainder of this sclerite thin, sharply terminated; second sclerite very large, distinctly curved and twisted medially, its proximal portion bottle-like.

Female. Similar to male but slightly larger. Labrum without spines; antennal segment II not bent, somewhat less stout, not covered with small setae, which are curved apically.

Measurements. Ψ/ɗ: body length 8.8–9.5/7.4, width 2.5–2.75/2.2. Head. Length 1.75–2.0/1.5, width 1.1– 1.3/1.35, diameter of eye in dorsal view 0.3/0.3. Antenna. Length of segment I 1.55–1.65/1.3, II 2.9/2.15, III 5.1/4.0, IV 2.6/2.45. Labium. Length of segment I 3.2–3.3/2.55, II 1.8–1.85/1.75, III 2.2–2.55/2.0, IV 1.7/1.4.

Pronotum. Length 1.75–1.8/1.3. width of anterior margin 1.0/0.7–0.9, length of lateral margin 1.8–1.9/1.5, width posterior margin 1.7–1.8/2.2–2.3.

Biology. Unknown.

Distribution. Malaysia (Borneo, Malay Peninsula).

Type material: Holotype ɗ: Sandakan Borneo Baker; Holotype Rhinocylapus scutatus T. Y. Hsiao; Holotype No. 56723 U.S. N.M. paratypes: 1 Ψ: Sandakan Borneo Baker; Paratype Rhinocylapus scutatus T. Y. Hsiao; Paratype No. 56723 U.S. N.M.; 1 ɗ: Sandakan Borneo Baker; Paratype No. 56723 U.S. N.M. (USNM).

Additional examined material. 1 Ψ: Sandakan Borneo Baker; Allotype Rhinocylapus scutatus T. Y. Hsiao; Allotype No. 56723 U.S. N.M.; 1 ɗ: N. Borneo, Samawang, nr. Sandakan, jungle, July, 1927; Exp. P. M. S. Museum. B. M. 1955-354; 1Ψ: Sarawak: Mt. Kalulong, 400–650 Pt. l. xi. 1932; Oxford Univ. Exp. B. M, 1933-254 (US).

Discussion. Gorczyca (2006) considered the data provided by Kerzhner & Konstantinov (1999, Fig. 14) for Rhinocylapidius sp. as referring to Rh. scutatus. However, the shape of the aedeagus of all known males of Rhinocylapidius and Rhinocylapus (except for Rhinocylapus simplicicollis) is not consistent with that pictured by Kerzhner & Konstantinov (1999) and the drawing most likely presents an undescribed taxon. Based on the single endosomal sclerite depicted in the drawing, which is unlike all known species of Rhinocylapus and Rhinocylapidius where the endosoma is complex, with numerous sclerites and sclerotized lobes, the illustration may even present an undescribed genus.