水蜡蛾一新属一新种(鳞翅目:水蜡蛾科)

A NEW GENUS AND SPECIES OF BRAHMAEIDAE (LEPIDOPTERA)

Brahmaea属是Walker（1855）以Bombyx certhia Fabricius为模式种成立的。Mell（1929）根据成虫形态特征、后翅翅脉的差异（有无连接Sc+R1和Rs脉的横脉）,将亚洲的水蜡蛾分为二群,建立一个新亚属 Brahmophthalma Mell并绘有Brahmaea Walker属与新亚属内每个种的翅脉简图以示区别;Bryk（1949）将Brahmophthalma提升为属。我们在整理和研究水蜡蛾的标本中,发现Brahmaea Walker属中实际存在着成虫形态和外生殖器差别很大的两个类群,作者认为有必要将其分为两个属,建立一个新属,并记述一新种。

Brachygnatha Zhang et Yang, gen. nov. (Figs. 1-4)This genus is characterized as follows: antennae and the space in between yellowish brown; upper surface of abdomen black or fuscous, without pale intersegmental cross belts;veins R2+3 separated in apical area of forewing.Male genitalia: with long uncus and complete gnathos; distal extension of sacculus digitate.Type species: Brachygnatha diastemata Zhang et Yang, sp. nov.The main differences between the new genus and its similar genus Brahmaea are as follows:Brachygnatha diastemata Zhang et Yang, sp. nov. (Figs. 5-6, 1-2)Male: forewing length 60 mm, body length 33 mm. Antennae and interspace yellowish brown. Frons fuscous, sides and hind part of tegula yellowish brown. Dorsum of mesothorax with a longitudinal line. Thorax ventrally fuscous. Dorsum of abdomen black. Venter of abdomen fuscous with median and side belts black. Spots between veins in the median belt of forewing and before M3 black-edged. Two small spots present between veins M3-Cu2 and 5 black N- shaped lines present across the costal margin. Breadth between median belt and first outer rivulis wide. Fuscous long hairs present on the basal half of hindwing; costal margin of hindwing yellowish brown ;breadth between the two sides of first rivulis rather wide.Male genitalia: Sides of tegumen undulant. Uncus long and curved ventrad, pointed distally, with a hairless narrow belt on the venter. Gnathos complete. Distal end of sacculus extended and digitate.Holotype , Haoping, Taibaishan, Shaanxi Province, 13- V - 1982 coll. by Sun and Li; the type specimen is deposited in the Insect Collections of Beijing Agricultural University, China.The species Brahmaea jilinensis Zhang, 1988 (Entomotaxonomia, Vol. X. No. 3-4) may be transferred to the genus Brachygnatha.The new species is similar to Brachygnatha jilinensis (Zhang), but may be distinguished from the latter in the first rivulis of hindwing dissociated and in some features of its male genitalia.