Peratophyga Warren, 1894

Jiang, Nan, Xue, Dayong & Han, Hongxiang, 2012, A review of Peratophyga Warren, 1894 in China, with descriptions of two new species (Lepidoptera: Geometridae, Ennominae), Zootaxa 3478, pp. 403-415 : 404

Peratophyga Warren, 1894

Peratophyga Warren, 1894 (April 16), Novit. zool., 1: 407. Type species: Acidalia aerata Moore, 1868 , by original designation. Peratophyga Swinhoe, 1894 (May 11), Trans. ent. Soc. Lond., 1894: 204. Type species: Acidalia aerata Moore, 1868 . [Junior homonym and junior objective synonym of Peratophyga Warren, 1894 April 16.]

Euctenostega Prout, 1916 , Novit. zool., 23: 38. Type species: Euctenostega hypsicyma Prout, 1916 .

Generic characters. Antennae bipectinate, serrate or filiform in male, filiform in female. Frons not protruding. Labial palpi extending slightly beyond frons. Hind tibia with two pairs of spurs in both sexes, dilated and with hairpencil in male. Outer margin of forewing smooth, that of hindwing often smooth, sometimes forming a sharp protrusion at end of M3 (in P. xanthyala ( Hampson, 1896) and P. oblectata Prout, 1929 ). Frenulum well developed. Forewing with a basal elliptic fovea in male except in P. hypsicyma ( Prout, 1916) and P. hypsidesma Holloway, 1994 . Wings usually pale yellow, with dark bands outside postmedial lines; postmedial lines often protruding inwards among M veins and below CuA2, with sparse spots inside. Forewing with R1 diverging from R2 near end of Sc and then anastomosing with Sc to end, R3–5 arising before anterior angle of cell, M2 often arising from anterior angle of cell, or sometime close to M1 and arising from above middle of discocellulars (e.g. P. flavomaculata Swinhoe, 1902 and P. re c t a sp. nov.). Tuft of scales present on male sternite III. Male genitalia with triangular uncus; gnathos connected at middle and with median process short to long, often rounded apically; valva bifurcate, forming a strong dorsal process and a ventral lobe, dorsal process bearing long setae at terminal half, slightly curved outwards or strongly angled, ventral lobe often triangular, incurved terminally; saccus rounded; coremata not developed; vesica of aedeagus often with two cornuti (basal one spinous terminally, e.g. P. grata stat. rev., P. crista sp. nov., P. v e n e t i a Swinhoe, 1902 and P. bifasciata Warren, 1905 , and P. xanthyala ), sometimes with one cornutus (long and narrow, with spines on lateral sides, e.g. P. trigonata ( Walker, 1861) , P. b e t a Holloway, 1994 and P. alluvialis Holloway, 1994 or short and spinous, e.g. P. hyalinata (Kollar, 1844)) , or with three cornuti (one of them shaped as a sclerotized disc, the other bulbous, e.g. P. spilodesma Prout, 1934 ), sometimes without cornuti, (e.g. P. re c t a. sp. nov.). Female genitalia with apophyses anteriores about one-half length of apophyses posteriores; lamella postvaginalis and lamella antevaginalis well developed; ostium and ductus bursae sometimes sclerotized; corpus bursae often oval, membranous, bearing a signum; signum variable in shape.

Diagnosis. The genus Peratophyga is externally similar to Stegania Guenée, 1845 and Zamarada Moore, 1887 , but it can be distinguished by the following characters: the forewing M2 arises from above middle of discocellulars, while in Stegania and Zamarada , it arises from the middle of the discocellulars; the postmedial lines of all wings are remote from the outer margins, while in Stegania , they are closer to the outer margins. In the male genitalia, the cornuti take different forms but never a bundle of spines as in Stegania ; the coremata are absent in Peratophyga but well developed in Zamarada .

Distribution. China, Japan, Korean Peninsula, Southeast Asia, Afghanistan.

Remarks. After examining the holotypes of P. castaneostriata Yazaki & Wang, 2004 and P. modesta Yazaki & Wang, 2004 (the both deposited in SCAU), we found that these two species well agree with the genus Stegania Guenée, 1845 in the following characters: the forewing M1 arises from the middle of the discocellulars; the postmedial lines of all wings are very close to the outer margins; the cornuti of the male genitalia are composed of a bundle of spines. Therefore we transfer them to that genus ( Stegania castaneostriata comb. nov. and Stegania modesta comb. nov.). Holloway (1994) reviewed the Bornean species of Peratophyga and divided the genus into five species groups. After examining the Chinese Peratophyga species, we find that P. hyalinata , P. grata stat. rev. and P. crista sp. nov. fall into hyalinata group, and are recognizable by the semihyaline wings and the triangular ventral lobe of the valva; P. xanthyala falls into xanthyala group, and is characterized by having the facies similar to that of Zamarada species and a tapering and incurved ventral lobe of the valva; P. recta sp. nov. and P. bifasciata do not appear to trigonata group, as they have the almost triangular and symmetric ventral lobe of the valva. So, here we propose a new species group, the bifasciata group, including P. re c t a sp. nov., P. bifasciata and P. flavomaculata .