96 THE LIFE-STORY OF INSECTS [CH. 



through the early summer months, in the case of the 

 Small Tortoiseshell ( Vanessa urticae) pupating before 

 midsummer and developing into a July brood of 

 butterflies whose offspring after a late summer life- 

 cycle, hibernate; while for the larger species of the 

 group there is, in our islands, only one complete life- 

 cycle in the year, though the same insects in warmer 

 countries may be double-brooded. C. G. Barrett 

 records (1893, vol. I. pp. 153-4) how in the August 

 of 1879 hundreds and thousands of ' Painted Ladies ' 

 (Pyrameis cardui) migrated into the south of England 

 from the European continent where in many places 

 great swarms had been observed early in the summer. 

 1 These August butterflies, the progeny of the June 

 swarms, coming from a warmer climate, had no in- 

 tention of hibernating, but paired and laid eggs. 

 Some of the larvae were collected and reared indoors 

 [butterflies] emerging in November and December, 

 but out of doors all must have been destroyed by 

 damp or frost, in either the larva or pupa state, for 

 no freshly emerged specimens were noticed in the 

 spring, and no trace of the great migration remained.' 

 In September and October the pedestrian, even 

 in a suburban square, may see moths with pretty 

 brown, white-spotted wings flying around trees. These 

 are males of the common ' Vapourer \0rgyia antiqua), 

 in search of the females which, wingless and helpless, 

 rest on the cocoons surrounding the pupae whence 



