Cidnopus nigronitidus Han and Lee, sp. nov.

Cidnopus nigronitidus Han and Lee sp. nov.

(Figs.1A–B; 2A–R; 3A–B)

Specimens examined. Holotype: male, Mt. Geryeong, Gongju, CN, Korea. 24. V. 1989. Y. J. Kwon [NAAS]. Paratype: female, Haean-myeon, Yanggu, GW, Korea. 13. VI. 1990. J. I. Kim [SWU]; female, Mt. Sobaek, Youngju, GB, Korea. 30. V. 1989. Y. J. Kwon [NAAS]; male, Mt. Odae, Jinbu, Pyeongchang, GW, Korea. 24. VI. 1998. T. M. HAN, DNA 3049.

Description. Holotype (Fig. 1A). Male 5.7 mm long, 1.7 mm wide. Body sub-cylindrical, rather broad, convex above, parallel-sided; color black, lustrous, with apex of mandibles, tibiae, tarsus dusky reddish brown; pubescences rather short, subrecumbent, pale yellow. Head (Fig. 2 D) flat between eyes; frontal margin expanded anteriorly at above antennal sockets, distinctly and thickly carinate but feebly sinuate inwardly, obscure at middle; punctures (Fig. 2 E) sub-circular, irregular, simple, deep, but becoming larger and subumbilicate, dense, coarse to outsides, intervals between punctures about 0.3–0.5 times narrower than the diameters of punctures; surface rather rugose laterally; eyes moderately prominent, with ocelli weakly convex; frontal groove (Fig. 2 F) transversely excavated, slightly narrowed at middle in anterior view; labrum semicircular with long setae anteriorly; mandibles bidentate; maxillary palpi (Fig. 2 Q) axe shaped. Antennae (Fig. 2 G) moderate; 1st antennomere robust, cylindrical; 2nd smallest, sub-globular, 1.5 times as long as wide (9:6), width sub-equal to 3rd (sometimes slightly wider than 3rd in females); 3rd sub-triangular, 1.66 times as long as wide (10:6), slightly longer than 2nd; 4th triangular, 1.33 times as long as wide, 0.63 times shorter than combined length of 2nd and 3rd segments (12:19); 4th to 10th bell-shaped, feebly serrated, each slightly longer than wide; 11th cylindrical, parallel-sided, longest, 2.0 times as long as wide (cat. from 2nd to 11th = 9/6, 10/6, 12/9, 11.5/10, 12/9.6, 12/10, 11/10, 12/10, 12/9.3, 18/9). Pronotum (Fig. 2 A) sub-quadrate, dome-like convex above, sub-equal in length with width (29:28), widest at middle; anterior margin simple; lateral margins entirely and finely carinate, entirely visible in dorsal view; anterior corner simple, arched from the widest and then slightly convergent anteriorly; punctures (Fig. 2 B) distinct, deep, sub-elliptical and of regular size (Fig. 2 C); intervals glabrous, about 1.2–2.0 times wider than punctures; hind angles (Fig. 2 H) broad, feebly sinuate at base and divergent posteriorly, with a distinct carina extending inwards at base; posterior margin (Fig. 2 I) lacking basal incisures and basal notch in front of scutellum. Prosternum (Fig. 2 L) convex, with simple punctures; anterior collar bent antero-inferiorly and roundly margined with punctures clearly large and sub-ocellated, subequal in length to anterior apex of hypomera; posterior process (Fig. 2 L and 2M) with longitudinal shallow impression between procoxal cavities, slightly bent beyond procoxal cavities and then expanded as pentagonal shaped laterally, ventral surface narrowly and longitudinally convex in lateral view, lacking a longitudinal depression along each side. Procoxal cavities narrowly open posteriorly; pronotosternal sutures double, smooth madially, but becoming rugose anterioly, slightly sinuate, anterior portion distinctly furrowed and expanded ventrally (Fig. 2 N); hypomeron rather broad, with simple sub-elliptical punctures, anterior portion weakly elevated along inner margin, posterior margin nearly straight, but weakly and smoothly emarginate near procoxal cavities. Scutellum (Fig. 2 J and 2K) tongue shaped, 1.37 times (22: 16) as long as wide, widest at apical two thirds; anterior margin narrowest, truncate; lateral sides parallel madially and then broadly and roundly expanded laterally; posterior margin rounded; punctures large, coarse. Mesocoxal cavities broadly connected with mesoepimeron and narrowly with mesoepisternum. Metasternum convex; median longitudinal suture distinct; hind coxal plates (Fig. 2 P) widest at insertion of trochanter, outer margin slightly convergent laterally. Legs slender; tarsomeres simple, claws (Fig. 2 R) simple. Elytra (Fig. 2 O) sub-ovate, convex above, widest before middle, 2.33 times (77:33) as long as wide, slightly wider than pronotum (33:29), gradually and slightly broadening from base before middle and then gradually rounded posteriorly; sutural line weakly elevated; base weakly convex along anterior edge; striae punctate, distinct; strial intervals feebly convex, weakly rugose transversely. Abdomen with each lateral margin of visible sternites entirely and weakly crenulate; sternite 7 semi-oval, 2.33 times wider than long (42:18). Aedeagus (Fig. 3A) 2.75 times (22: 8.0) as long as wide; median lobe slender, sub-parallel-sided and then suddenly narrowed from anterior one fourth to apex, a little longer than parameres, 3.69 times (12.2: 3.3) longer than basal struts; parameres slightly narrow to apex, lateral margins very feebly sinuate, inner margins almost straight, with lateral subapical barb expanded strongly; lateral subapical barb round at anterior margin, 1.47 times (2.8: 1.9) as wide as long, with visible two setae sited on anteror-median portion; basal piece quadrate, widest just after middle, a little wider than long (1.1 times; 8.8: 8.0), 0.36 times (8.0: 22.0) total length of aedeagus.

Female (Fig. 1B). Length 6.6–7.0 mm, width 2.1–2.6 mm, larger, stouter than male; antennae shorter than male, approximately reaching to base of hind angles of pronotum, 4th antennomere distinctly wider than long (1.53–1.57 times); pronotum more convex and 1.05–1.06 times wider than long. Reproductive organs: ovipositor sub-triangular, with styli; vagina (Fig. 3B) elongate; uterus enlarged at anterior, with ballon-like colleterial glands, lacking sclerotised structures; bursa copularix elongate, cylindrical, sub-equal in length with width from base to apical, coiled from apical half, with two accessory glands; basal accessory gland distinctly elongate, longer than second accessory gland.

Reference species. Cidnopus koltzei (Reitter, 1895): 2 females, Russia, Sakhalin, Yuzhno-Sakhalinsk, Vestochka. 18. VII. 2008. J. W. Lee, identified by T. M. Han, DNA 2606 and 2607; Cidnopus marginicollis (Lewis, 1894): male, female, Mt Gomandodan, Wakayama Pref, Honshu, Japan. 31. V. 1986. Leg. H. Hiramatsu, identified by Dr. H. Ôhira, DNA 3044.

Etymology. This new species was named C. nigronitidus based on its black shining body.

Diagnosis. This new species is closely allied to C. koltzei (Reitter, 1895), which occurs from Russian Far East to Mongolia. We examined two female specimens of C. koltzei collected from Is. Sakhalin, Russia. By comparative examination of the females of these two species, the new species can be easily distinguished from C. koltzei by the following characteristics: In the former, the 2nd antennomere is subequal in length to the 3rd, the pronotal lateral margin is slightly arched in the middle, the prosternal process has a shallow impression between the procoxal cavities, and the lateral expansion of the prosternal process is rather short. In the latter, the 3rd antennomere is slightly longer (1.18−1.27 times) than the 2nd and almost parallel-sided from the anterior one-fourth posteriorly in the pronotal lateral margin, and the prosternal process is flat between the procoxal cavities and more or less elongate posterioly. In particular, the novel species is clearly distinguished from C. koltzei by the shape of the bursa copulatrix (BC) of the female. The former has a cylindrical BC with a distinctly elongated basal accessory gland, but the latter has a more enlarged BC with a short basal accessory gland (Fig. 3 C).

Mertlik (1996: 207) provided a key of six European species of Cidnopus. According to this scheme, C. nigronitidus sp. nov. shares the same diagnostic characteristics, such as a slightly convex pronotum and visible lateral margin in the dorsal view, with C. crassipes (Schwarz, 1900) in Turkey, C. pilosus (Leske, 1785) in Europe and Asia minor, and C. koltzei (Reitter, 1895) in Far East Russia. We did not examine a specimen of C. parallelus (Motschulsky, 1860) in this study. Cidnopus nigronitidus sp. nov. can be easily separated from C. parallelus. Reitter (1895: 256) characterized C. parallelus as having the carinate pronotal hind angle, which is invisibly and completely coincident with the lateral margin. Additionally, Gurjeva (1989: 494 and 501) illustrated the hypomeron, aedeagus, and the dorsal habitus of C. parallelus. Especially, the aedeagus of C. parallelus has subtriangular shape (not roundly expanded to apex) in the subapical barbs of the parameres and distinctly sinuate at the inner margins of the parameres.

Distribution. Republic of Korea.