378 BRITISH LEPIDOPTERA. 



and early July, and larvae are obtained in August, and imagines again 

 in September and October. In other years, e.g., 1895, x 9 OI 5 & c -> 

 immigrant imagines appear in August, larvae and pupae from Septem- 

 ber to November, and imagines from October until killed oft by the 

 winter, only forced pupae, in confinement, maturing their imagines. 

 In other years, e.g., i860, 1861,1871, 1875, 1876, 1877, 1881, 1883, 

 1885, 1886, immigrant imagines do not appear until late August 

 and September, and, in such years, probably due to insufficient food 

 or temperature, or both, eggs are rarely deposited or larvae found. 

 The mode of occurrence of the species from Britain across Europe 

 and Asia to northern Japan is very similar, and the occasional 

 capture of isolated early summer examples leads to the statement in 

 most local European lists of lepidoptera that the species occurs in 

 " May-June" and "August to October," with a saving clause 

 frequently added, " sometimes in July." Thus, Barte], who summarises 

 the German records, notes (Pal. Gross-Sehmett., ii., p. 39) : " The 

 imagines emerge either after a pupal period of four weeks, between 

 August and October of the same year, or more rarely from hybernated 

 pupae in May and June, exceptionally also in July. The moths 

 emerging in August and September are not adapted to yield progeny, 

 and those larvae which, with us, are observed still in October and No- 

 vember, mostly fall victims to the early advent of cold, and cannot, 

 therefore, be the offspring of the autumn brood as is often erroneously 

 stated, but must come from winter pupae that were specially late in de- 

 veloping."* Most of the records for the continent of Europe and northern 

 Asia suggest that the appearances are identical with ours in Britain, 

 and consist of the general statement of an early and late brood, 

 the remarks concerning the former pointing either to its great 

 rarity or to a theoretical acceptance of an early one in order to explain 

 the later one. Thus, we have June and July, and again in September 

 and October in the Netherlands (Snellen), in June and September 

 in Belgium (Derenne), May -June and again August-October in 

 Germany (Heinemann), May-June and often very abundantly in 

 August-September at Baden (Reutti), June rare, and August-Sep- 

 tember at Crefeld {teste Bartel), June and September-October at 

 Halle (Stange), May-June and August-September in Thuringia 

 (Krieghoff), end of May and again in September at Wiesbaden 

 {teste Bartel), June and September in Alsace (Peyerimhoff), June 

 and again in August-September at Budapest, mid-June to the 

 end of September in Tuscany {teste Bartel), June and again in 

 September-October at Collo, in Algeria (Seriziat), all point to 

 an occurrence very similar to that in England though details 

 are wanting to show how rare the examples of the so-called 

 early brood are in the northern, and how far more abundant in the 

 more southern, European countries. But none of these eliminate 

 the facts exhibited in our details and dates ot appearance, viz., 

 that besides occasional May-June examples (which are almost certainly 

 immigrants) there may be distinct July-August and September-October 



* This paragraph is altogether erroneous and misleading (sec an tea, pp. 343- 

 345 and 376) where are several definite cases of larvae, pupae and imagines obtained 

 from August- September parents. The e^s on which Poulton's life-history of 



this species was based (antch, pp. 337 et st'tj.) were laid on August 26th, 1887. 



