Cyphon atratus ( Motschulsky, 1863 ) Motschulsky, 1863

Ruta, Rafał, 2009, Revision of Scirtidae (Insecta: Coleoptera) described by Victor Ivanovitsch Motschulsky, Zootaxa 2210, pp. 26-50 : 27-31

Cyphon atratus ( Motschulsky, 1863) comb. nov.

( Figs. 1 , 16–22 )

= Hydrocyphon atratus Motschulsky, 1863: 486

Type material. Lectotype (present designation), male: [small, yellow, round label]; “ type ” [small rectangular label, handwritten]; [red rectangular label]; “ Hydrocyphon / atratus / Motsch / Ind. or. Ceyl. Mt. N.” [yellow rectangular label, handwritten]; deposited in ZMUM. Paralectotype, female: same data as lectotype; deposited in ZMUM.

Note. The two specimens were originally pinned together. One is a male representing the chlorizans group of Cyphon , the other is a female in the genus Hydrocyphon . The specimen resembles externally Hydrocyphon rufithorax , and most probably it is a female of this species. Motschulsky himself was not certain of status of this form (“either a variety of my Hydr. ruficollis with dark pronotum, because it has its length and shape, or different sex of this species”, Motschulsky 1863: 486). The specimen belonging to the genus Cyphon is designated as a lectotype.

Diagnosis. Body is small, with yellowish-red head and pronotum, contrasting with dark brown (to almost black) elytra. The species is externally resembling Cyphon pseudoatratus Ruta, 2007 , but it differs in having a bicoloured body and in details of genital anatomy. The penis is distinctly narrower, trigonium subtriangular, and sternite 9 has straight lateral arms.

Redescription. Lectotype, male. Measurements: TL 1.60, EW 1.00, EL 1.30, PW 0.65, PL 0.30, HW 0.50, HL 0.30, interocular space 0.30, greatest depth of body 0.55.

Body small, oval, convex, covered with setae which are easily broken and lacking in the lectotype. Elytra, meso- and metaventrite dark brown; head, pronotum, prosternum and scutellum yellowish-red. First pair of legs yellow, remaining missing in the lectotype. Mouthparts yellow, basal 2 antennomeres yellow, remaining missing in the lectotype. Body length 1.6X width.

Head width 1.7X length, 1.7X width of interocular space, with subtle granulate punctation, eyes large, protuberant. Antennomeres 1 and 2 globular, remaining antennomeres missing in the lectotype, length ratios of antennomeres 1.3: 1.0; L/W ratios of antennomeres 1.6, 1.5. Anterior clypeal margin straight, labrum transverse, with rounded anterolateral angles. Mandibles triangular with tempered apices, right mandible with a small denticle on mesal edge.

Pronotal width 2.2X length, pronotum widest at base. Pronotal disc with fine granulate punctation. Posterior margin of pronotum bisinuate. Anterior angles slightly protruding, posterior angles obtuse. Lateral margins slightly narrowing anteriorly. Pronotum distinctly narrower than elytra. Scutellum subtriangular, almost impunctate.

Elytra oval, without distinct longitudinal ridges, length 1.3X width; length 4.3X length of pronotum, broadest in the middle of its length. Sides regularly converging to apex in posterior half. Humeri clearly evident. Punctation fine, granulate, distance between punctures ca. 1.5–2.0 diameters. Epipleura narrow, abruptly narrowed behind metaventrite, reduced in apical part. Hind wings fully developed.

Prosternal process tear-shaped, length ca. 1.5X width, apex rounded. Mesocoxae separated by a process (length ca. 4.0X width) dilating posteriorly; metaventral discrimen complete. Ratio of ventrites’ lengths: 1.0: 2.0: 2.0: 2.0: 2.1.

Male genitalia. Penis (L 0.70, W 0.10) narrow, distal region elongate, rounded apically, trigonium armed apically with several minute denticles; tegmen (L 0.78, W 0.14) long, bifid in the middle of its length, Yshaped; sternite 8 (L 0.48, W 0.17) bifid apically, Y-shaped; sternite 9 (L 0.77, W 0.22) large, U-shaped with straight unarmed lateral arms; tergite 8 (L 0.36, W 0.26) with short apodemes and sparse setae on apical margin; tergite 9 (L 0.51, W 0.22) with long apodemes, devoid of setation at apex. Female unknown.

Remarks. This species is a member of the second subgroup of the chlorizans group of Cyphon ; the group is widely distributed in SE Asia (species listed in Ruta 2007).

Figures

FIGURES 1 – 8. Habitus illustrations. 1) Cyphon atratus; 2) Cyphon ovalis; 3) Cyphon flavescens, male; 4) Cyphon flavescens, female; 5) Hydrocyphon rufithorax, male; 6) Hydrocyphon rufithorax, female; 7) Mescirtes gagatinus; 8) Mescirtes gagatunus, close-up. Scale bar = 1.0.

FIGURES 16 – 22. Cyphon atratus, male. 16) penis; 17) penis, close-up; 18) tegmen; 19) sternite 8; 20) sternite 9; 21) tergite 8; 22) tergite 9. Scale bar = 0.25.