Cyphon mahensis Champion, 1924

Ruta, Rafal, 2008, Contribution to the knowledge of Seychellois Scirtidae (Coleoptera: Scirtoidea), Zootaxa 1913, pp. 49-68 : 55-56

Cyphon mahensis Champion, 1924

( Figs. 19–29 )

Type material (1 male). Holotype. Mounted on card bearing number 85 [Mare aux Cochons District, 1000- 2000ft., 26.i.1909]; “ Type H. T.” (printed label); “ Mahe, 1908-9. / Seychelles Exp.” (printed label); “Percy Sladen / Trust Exped. / Brit. Mus. / 1926-246.” (printed label); “ Cyphon mahensis / type Ch.” (handwritten). Deposited in NHM.

Additional material studied (2 females). Mounted on card bearing number 84 [Mare aux Cochons District, 1000-2000ft., 26.i.1909] and 40 [country above Port Glaud, 500-1000ft., 5.xi.1908]; “ Mahe, 1908-9. / Seychelles Exp.” (printed label); “Percy Sladen / Trust Exped. / Brit. Mus. / 1926-246.” (printed label); “ Cyphon mahensis / Champion, 1924 / det. R. Ruta 2007 ” (printed label). Specimen with number 40 on a card bears additional labels: “Front coxae conical, very exserted / middle + hind transverse / not exserted. Metasternum / very short. 5 ventral sgts. / Abdomen pointed, hairy” (handwritten by Champion), “ Cyphon / sp.?” (handwritten by Champion). Deposited in NHM.

Diagnosis. Body minute, uniformly brownish-black, elongate, female apterous. Certain identification is possible only on the basis of male genital morphology (penis with long parameroids and short centema, male sternite 9 small, Y-shaped, female sternite 8 with fused apodemes).

Redescription. Holotype, male. Measurements: TL 1.6, EW 0.9, EL 1.33, PW 0.6, PL 0.4, HW 0.48, HL 0.3, interocular space 0.3, greatest depth of body 0.65.

Body small, oblong, very convex, covered with suberect brown setae, which easily break and are lacking in the holotype. Dorsum brownish black, underside of the body dark brown. Legs, mouthparts, and antennae brownish, femora brown, tibia and tarsi lighter, yellowish. Body 1.78 times as long as broad.

Head 1.6 times as broad as long, 1.6 times wider than width of interocular space, with very subtle granulate punctation, eyes moderately protuberant. Antennae filiform, antennomere 1 and 2 semiglobular, antennomere 3 shortest, antennomere 4 longest; length ratios of antennomeres (only 4 antennomeres present in holotype) 2.0: 1.33: 1.0: 1.33; length/width ratios of antennomeres 1.5, 1.0, 1.5, 1.0. Anterior clypeal margin straight. Labrum semicircular. Mandibles symmetrical, without denticles on mesal edges.

Pronotum small, 1.5 times as broad as long, widest at posterior angles. Disc of pronotum with subtle, granulate punctation similar to that on head. Posterior margin of pronotum bisinuate. Anterior angles not produced.

Scutellum subtriangular, slightly damaged in holotype. Base of elytra evenly wider than base of pronotum.

Elytra elongate, without longitudinal ridges, 1.48 times as long as broad and 3 times as long as pronotum. Sides regularly converging to apex in apical 1/3. Humeri clearly evident. Punctation shallow and sparse, distance between punctures ca. 2 diameters. Epipleura narrowed beyond metaventrite, reduced in apical 1/3. Hind wings fully developed.

Prosternal process elongate, with rounded apex. Mesocoxae separated by a subparallel process which dilates only slightly posteriorly (ca. 3 times as long as wide), metaventral discrimen complete. Ratio of ventrites’ lengths: 1.0: 2.0: 1.8: 1.6: 1.8. Ventrite 5 regularly rounded.

Male genitalia. Penis (L 0.5, W 0.13) with long parameroids and short centema; tegmen (L 0.72, W 0.1) Y-shaped, very long and bifid in apical 1/4; sternite 9 (L 0.26, W 0.11) small, Y-shaped; tergite 8 (L 0.73, W 0.35) long, with long apodemes and row of setae on apical margin; tergite 9 (L 0.82, W 0.18) with long apodemes and long setae on apex. Apical part with membranous connection between hemitergites.

Female. TL 1.45 (n = 2). Sexual dimorphism indistinct, body dark brown, wingless, metaventrite very short (L/W = 0.2, in male: 0.28) as long as mesoventral process in female, 1.5 times as long as mesoventral process in male (probably correlated with reduction of hind wings). Female genitalia. Ovipositor (L 1.25, W 0.1) long; tergite 8 (L 0.85, W 0.25) with long apodemes; sternite 8 (L 0.53, W 0.19) Y-shaped, with setae on apex. Prehensor not found (missing or reduced and indistinct).

Remarks. Cyphon mahensis belongs to the widely distributed in SE Asia chlorizans -group of Cyphon PAYK. Due to reduction of sternite 9, it may be classified within subgroup I known till date from Japan, China, Nepal and India ( Ruta 2007).

Figures

FIGURES 19 – 29. Cyphon mahensis Champion. 19) holotype; 20) holotype labels; 21) female specimen labels; 22) penis; 23) penis, close-up; 24) tegmen; 25) sternite 9; 26) tergite 8; 27) tergite 9; 28) female sternite 8; 29) female tergite 8. Scale bar = 0.2 mm (for Figs. 22, 24 – 29).