484 THE BUTTERFLIES OF NEW ENGLAND. 



Life history. Notwithstanding the ubiquity and general abundance of 

 Vanessa cardui, its natural history is still imperfectly known. Of its 

 life in the tropics there is no published statement beyond the mention by 

 the indefatigable Horsfield, that in Java the butterfly appears in December. 

 Just beyond the tropics, at the Cape of Good Hope, Trimen reports it as 

 found in the imago state throughout the year, but most abundant from 

 September to March. At about an equal distance north of the tropics, 

 on the same continent, in Egypt, this buttei*fly flies through the winter, 

 and I have found caterpillars in almost every stage from November to 

 March. 



In New England this butterfly is double-brooded and hibernates in the 

 imago state, — at least so far as is known. In Europe, according to some 

 writers, it often passes the winter in the chrysalis state : but authorities do 

 not agree upon this point. The hibernating butterflies do not usually 

 begin to emerge from their winter quarters until the middle of May, and 

 badly worn specimens continue to fly until after the middle of June. 

 They lay their eggs during the latter half of May and early in June ; 

 and the caterpillars therefrom become fully grown between the middle of 

 June and the end of July ; the chrysalids hang from eight to fourteen 

 days, and disclose the first fresh butterflies about the 10th of July. These 

 usually become abundant by the middle of the month, and at the end of 

 the third week innumerable (though it would appear as if they sometimes 

 were delayed until the first week in August) ; they continue to emerge 

 from the chrysalis until the early days of August, and fly until the next 

 brood appears ; they lay their eggs during the last of July and the first of 

 August, and the caterpillars undergo their final transformations in the lat- 

 ter half of August and early in September, the autumn brood of butter- 

 flies first appearing late in August and continuing on the wing until the 

 end of October, when they hibernate. In the south they fly all winter. 



This account does not correspond with the history of the same insect in 

 Europe. Meyer-Diir states that in Switzerland the butterfly may be seen 

 on the wing from April to the end of June (wintered specimens), and 

 from the middle of August until late in October: that is, it is single- 

 brooded. Many authors speak of it as double-brooded, without mention- 

 ing the specific times at which it may be found ; while others give the 

 same seasons as Meyer-Diir and call it double-brooded, mistaking the 

 double apparition of the same brood (winter intervening) for distinct 

 broods. My own observations in the neighborhood of Geneva and Paris 

 lead also to the conclusion that the insect is single-brooded ; and the only 

 entomologist, to my knowledge, who has given two distinctly separated 

 dates for the apparition of the caterpillar is Reutti, who says in his Fauna 

 of Baden, to which my attention was called by Dr. Speyer, that caterpil- 

 lars are found in June, August and September. But Dr. Speyer thinks 



