Puhl. 31. V. 1912. PYGAERA. By Dr. K. Grunberg. 313 



P. sangana Moore (47 c). Vertex greyish white, body dark brown, patagia and intersegmental inci- sangana. 

 sions of abdomen grey. Forewing dark grey-brown, more or less suffused with yellowish grey, the black pre- 

 and postdiscal bands rather sharp, marginal band nearly as in fhvescens, but much less prominent on the dark 

 ground ; discal spot and a round light spot before apex of cell indistmct ; the apical patch also often indistinct 

 and hardly contrasting with the ground-colour. Hindwing dark brown. — It is one of the large species charac- 

 teristic of the Indian fauna. Its true home is India, the species being found only in the boundary districts of 

 the Palearctic Region and extending northward to Shantung; it is not abundant. 



P. sigmata Butl. (47 e, as signata). Forewing grejdsh white, dusted with numerous black-brown scales; sigmala. 

 prediscal band indistinct; discal spot composed of erect black scales; close beyond cell 3 irregular dentate black- 

 brown transverse lines, and along the distal margin a row of black 22-shaped markings. Hindwing dark brown. 

 — ■ Japan, West China; common. 



39. Genus: I*ygaera 0. {Jchthyaia. Hh7i). 



Head small, strongly retracted. Antennae pectinate to the apex, the branches long in (^, short in ?. 

 Palpi rather large, porrect, extending above frons, densely hairy. Proboscis vestigial. Eyes hairy, ocelli absent. 

 Thorax densely hairy, with raised median crest; abdomen slender, pointed m J with forked anal tuft. Legs 

 densely hairy, especially the forelegs, which bear in most species very dense woolly hair down to the tarsi. Hind 

 tibia with mid- and end-spurs. Forewing broad, the apex slightly anguliform or rounded, distal margin more 

 or less strongly convex, sometimes excised below apex, hind angle rounded; vein 6 from upper angle of cell 

 or shortly stalked with 7, 8, 9, 10; no areole. Hindwing broadly rounded, veins 6 and 7 on a short stalk, 

 5 but slightly developed. — The eggs are semiglobular, moderately convex or lentil-shaped, irregularly 

 ribbed and reticulated. Larvae cylindrical, with rather dense and moderately long hair, on abdominal segments 

 1 and 8 with diversely developed, sometimes transverse tubercle or protuberance, in addition small warts and 

 tubercles which may be present from thoracical segment 2 backwards on the dorsum as well as sides, and some- 

 times are enlarged to processes on the thorax. The larvae feed on Salix and Poplar, and there are usually 2 

 broods in the temperate districts. Pupation in a loose cocoon between the leaves of the food-plant, more rarely 

 on the ground. The pupae have a strong gloss; the anal end of the larger number of species is produced into 

 a long thin process which bears several small hooks. 



The species of Pygaera incline to hybridisation. The closely allied and easily procurable species, such 

 as curtula, pigra and anachoreta are therefore favourite objects, like the species of Celerio among the SpMngidae, 

 for experiments in cross-breeding. The best-known hybrids obtained are the followmg : Pyg. hybr. fritna Tutt 

 {curtula ^ X pigra $), hybr. inversa Tutt {pigra ^ x curtula 9), hybr. difficilis Tutt {anachoreta ,^ x curtula $), 

 hybr. raeschkei Standfs. {curtula (J x anachoreta $). Moreover, the resulting product of a recrossing of these 

 hybrids with the parent species have also been described. Lately the Pygaera-\vyhviAs, have been used for invest- 

 igating the Mendelian law of heredity. 



P. timon Hhn. (47 f ). Greyish brown, with whitish or reddish tinted pre- and postdiscal and sub- timon. 

 marginal bands, the two outer ones commencing with a iii'ominent white costal spot; before the first band a 

 red-brown or black-brown transverse band which is centrally enlarged to a triangular spot proximally narrowly 

 edged with white. Hindwing greyish brown, with feebly marked light median band. — Occurs especially in Russia 

 but is very rare even there, single specimens occasionally obtained in Finland, East Prussia, Moravia and Upper 

 Hungary. Also in East Asia, Amur and Ussuri districts and Japan. Egg glossy light green. Larva from 

 June to August on Aspen, always singly, dark ashy grey, with short ashy grey hair, on the raised abdominal 

 segment 1 four and on the following segments two small red wart-like tubercles. Abdominal legs dark greyish 

 green. Pupa dark brown, with obtuse anal end, on the ground or between leaves in a loose whitish web. The 

 larvae are easy to rear, accepting also Black Poplar as food. 



P. timonides Brem. (= timoniorum Brem., latipennis Butl.) (47 f). Easily recognised by the distal thnonides. 

 margin of the forewing being excised below apex and projecting between veins 5 and 4. Dark brownish grey; 

 forewing with a rather large triangular blackish spot whose base rests on the costa, while the tip extends to 

 near the hmd margin; pre- and postdiscal and submarginal lines blackish, diffuse. — East Asiat Amur and 

 Ussuri districts. North China, Japan. 



P. denticulata Oberth. (56 d). Larger than the previous, forewing longer, its outer margin more strongly dentindata. 

 dentate, with an especially large tooth in the centre; ground-colour grey, forewing with similar markmgs as in 

 timonides, but the darker costal triangle only reaches to the centre of the wing instead of to the hind margin. 

 Hindwing with darker anal area, otherwise without markings. • — • Sze-chuen. 



II 40 



