374 LEPIDOPTERA. 



at uight it; flies vigorously, comes occasionally to light, and is 

 strongly attracted by sugar and ivy-blossom, on either of 

 which it settles down, and is captured with perfect ease. 

 Most uncertain in its times of appearance, usually scarce 

 except perhaps on the extreme South coast, but in certain (or 

 rather uncertain) years appearing in large numbers in the 

 autumn and extending its range very widely. The early — 

 May or June — brood is very rarely taken in this country, 

 and for this reason I have furnished, above, full evidence of 

 its existence, but the number of eggs laid by the female is 

 so large — approaching one thousand in number — and the 

 larva feeds so vigorously and rapidly in warm weather that 

 the produce of a very small number of specimens in the 

 early summer is sufficient to furnish a respectable emergence 

 in the autumn. Yet there can be little doubt that our native 

 produce is reinforced at times by a strong contingent from the 

 Continent of Europe. It is a swift and powerful insect and 

 possessed of a migratory instinct, which would naturally bring 

 it to us when at all crowded in its more congenial localities. 



In the years 1856-7-8 it suddenly became common in the 

 Southern counties and very widely distributed, occurring 

 even in the suburbs of London ; after that it was again scarce 

 for a number of years, but in 1867-9 again appeared in such 

 profusion as to be found in hundreds at Brighton and Deal, 

 and to extend into Scotland ; and similar fluctuations have 

 taken place in subsequent years. On the South coast from 

 Kent to Devon, Cornwall, and the Scilly Isles it may be taken 

 annually, and when abundant there, is apt to be so in Berks, 

 Somei'set, Gloucestershire, Surrey, Oxfordshire, Essex and 

 elsewhere in the southern counties ; far more scarce in 

 the Cambridgeshire fen district ; found casually in Leicester- 

 shire, Staffordshire, and Derbyshire ; more frequently in the 

 East coast counties from Suffolk to Yorkshire, and in the 

 West in Herefordshire, Cheshire, and Lancashire ; indeed, 

 its spread seems to take place more particularly along the 

 coast. Apparently very local in Wales, though it has occurred 



