Ypsiloncyphon sumatranus, Yoshitomi, Hiroyuki, 2015

Yoshitomi, Hiroyuki, 2015, New species of the genus Ypsiloncyphon (Insecta: Coleoptera: Scirtidae: Scirtinae), Zootaxa 3904 (4), pp. 451-500 : 474-476

Ypsiloncyphon sumatranus sp. n.

( Figs. 13 G, 20)

Type material. Holotype ( SMNH): male, “ INDONESIEN: Sumatra, Prov. Aceh-Selatan, Babahrot 15. -20. 8. 1983 leg. J. KLAPPERICH”.

Description. Male. Body ( Fig. 13 G) oval, strongly convex dorsally, shiny, closely covered with silver setae. Coloration of head and pronotum brown; scutellar shield, elytra, and meso- and metaventrites blackish brown; mouthparts, antennae and legs pale brown, but femur dark brown.

Head relatively large, slightly convex dorsally, finely punctate, front margin of clypeus straight. Eyes large, prominent; the distance between eyes about 1.8 times as long as the maximum diameter of an eye. Pronotum densely punctate, strongly depressed in lateral parts; anterior and lateral margins straight; posterior margin gently arcuate; antero- and postero-lateral corners right-angled; PW/PL 2.00. Scutellar shield finely punctate, equilaterally triangular. Elytra oval, widest at proximal 1/3, punctate as on pronotum; humeral parts projecting dorso-laterally; apices right-angled; EL/EW 1.26; EL/PL 3.40; EW/PW 1.35; TL/EW 1.63. Legs relatively slender.

Caudal margin of sternite VII arcuate. Tergite VIII ( Fig. 20 A) well sclerotized, transverse, bearing short spines at caudal margin, with a pair of relatively long apodemes. Tergite IX ( Fig. 20 B) well sclerotized, trapezoidal, with a pair of claw-like projections situated near postero-lateral corner, with a pair of long and slender apodemes. Sternite VIII ( Fig. 20 D) long, well sclerotized, Y-shaped, bifid in apical 1/6. Sternite IX ( Fig. 20 C) very long, well sclerotized, U-shaped, pointed at apices. Tegmen ( Fig. 20 E) long, well sclerotized, about 1.4 times as long as sternite IX, Y-shaped, bifid in apical 1/6, pointed at apices. Penis ( Fig. 20 F) long, well sclerotized, as long as tegmen; pala long, with straight basal margin; parameroids long, finely punctate; trigonium elongate, protruding from basal 5/9, curved ventrally, with thumb-like centema.

Female. Unknown.

Measurements. Male (n = 1): TL 1.76 mm; PW 0.80 mm; PL 0.40 mm; EL 1.36 mm; EW 1.08 mm.

Distribution. Indonesia (Sumatra Isl.).

Remarks. This species is remarkable in having claw-like projections on the tergite IX and a thumb-like centema at the apex of the trigonium. The shape of the penis in having long parameroids and pala of this species is similar to that of Y. acer sp. n., Y. jiangxiensis (Yoshitomi) , and Y. formosus (Klausnitzer) . Etymology. The species is named after the type locality.

Figures

FIGURE 13. Habitus of Ypsiloncyphon spp., holotype, male (except for F). A) Y. guamensis sp. n., B) Y. philippinensis sp. n., C) Y. panayensis sp. n., D) Y. chlorizanoides sp. n., E) Y. bicolor sp. n., F) Y. bicolor sp. n., paratype, female, G) Y. sumatranus sp. n., H) Y. acer sp. n., I) Y. nokrekensis sp. n., J) Y. boukali sp. n., K) Y. javanicus sp. n., L) Y. nepalensis sp. n. Scales: 1.0 mm.

FIGURE 20. Ypsiloncyphon sumatranus sp. n., holotype, male. A) tergite VIII, B) tergite IX, C) sternite IX, D) sternite VIII, E) tegmen, F) penis in ventral view.