458 BRITISH LEPIDOPTERA. 



and commencement of October, but Viret notes that, although the 

 insect occurs generally in September in the Seine-Inferieure, yet it is 

 occasionally captured in April. South of the equator at Durban, 

 14 larvae, fullred in January, 1901, only produced 2 perfect 

 imagines one of which emerged on February 1 8th, the other on 

 February 25th, the pupal stage having lasted 21 days; in May, 1901, 

 7 larvae of the next brood pupated (the last on May 26th) and all 

 emerged in September, two on the 7th, one each on the 9th, 13th, 16th, 

 19th, and 20th, after a pupal period of 4 months, so, that here 

 also the hybernation appears to be a pupal one (Leigh ; Ent., 

 xxxiv., p. 348). Our dates show pretty conclusively that the 

 earliest European arrivals (or emergences) vary from year 

 to year (in some years the species is entirely absent in the 

 greater part of Europe), but usually appear to be in May and June, 

 e.g., Mathew records a specimen taken on board a cruiser oft 

 Southwold, on April 28th, 1903 (Ent., xxxvi., p. 192), &c. (For 

 other records see anted pp. 439 et seq.) If the weather be fine on 

 their arrival they lay eggs at once, and larvae are found in July, 

 imagines in August, larvae again in August, September, and 

 October, imagines (very few in proportion to the number of 

 larvae sometimes captured) in September, October, and November. 

 It is from this late brood that most of the forced examples 

 raised in Britain and central Europe are obtained. But many 

 lepidopterists of central and eastern Europe believe that the species 

 is sedentary with them. Fuchs discusses (Ent. Zeit. Guben, 1890, 

 no. 10) this point and concludes that it is indigenous in Lower Austria, 

 whilst on the whole, too, Aigner-Aban thinks (lilus. Zeit. filr Ent., 

 iv., p. 212) that the species is sedentary in Hungary, surmising 

 that the species is sufficiently abundant every year in some 

 variable central area where imagines are not uncommon, that the 

 few spring imagines, which are, he asserts, very fruitful, come from these 

 centres, although the great mass of the hybernating pupae must perish. 

 The fact that imagines have been captured in June, e.g., at 

 Aschaffenburg (S.E.Z., 1887, p. 257), Coblenz (En/. Zeit. Guben, vi., 

 p. 32), Meissen (Iris, v., p. 396), appears to us only to support our 

 own view, and not to prove, as Fuchs holds, that the pupae from which 

 these came wintered where the imagines were found. Pabst appears 

 to hold the view that we ourselves have suggested as that 

 best met by the evidence. He suspects the spring immigrants 

 into Europe to be largely gravid ? s ; he further considers that, 

 in its most southern localities, the species is triple-brooded, 

 imagines appearing (1) at the end of May, (2) at the end of 

 July, and (3) at the end of August and beginning of September, 

 this latter being only a partial brood. He says that, at Vienna (teste 

 Fuchs) and at Dresden (teste Steinert), the moths do not appear 

 from hybernating pupae until the end of June, and that their progeny 

 produce imagines that appear partly in autumn and partly not 

 until after the winter, whilst Unzicker, who reared the species 

 from eggs laid by a $ found in May, states (Ent. Zeit. Guben, 

 1892, p. 82) that, of the imagines reared from these eggs, part 

 emerged between October 17th and November 7th, the rest not 

 until the following spring, and Gauckler, who obtained larvae 

 in August, 1883, at Hirschfeld, bred the imagines between September 



