THE NATURAL HISTORY OF AJVOS/A PLEXIPPUS IN 



NEW ENGLAND. 



BY SAMUEL HUBBARD SCUDDER, CAMBRIDGE, MASS. 



This butterfly pusses the winter in 

 the imago state. In southern h^titudes, 

 according to Edwards, who has given 

 it closest attention, it appears early in 

 the spring and lays eggs upon the milk- 

 weed just out of the ground, beginnir.g 

 in West Virginia in the early part of 

 May. The insect matures there very 

 rapidly, and passes through several 

 generations, according to Mr. Edwards 

 at least three, and probably four, in 

 the course of the season, the latest 

 brood of the butterflies hibernating. 

 Riley, who was the first to give a toler- 

 ably full life history of the insect, 

 claimed that in Missouri it was double- 

 brooded, the broods appearing in the 

 latter half of June and in October. In 

 New England, however, what we can 

 learn of the butterfly indicates a some- 

 what different history. Some years 

 ago, in publishing an account of its 

 history here, I claimed that the insect 

 was only single-brooded, first coming 

 out of hibernation at the end of June 

 and early in July, laying eggs for a 

 month or so, and the butterflies from 

 these eggs hibernating. A great many 



points concerning its history both here 

 and elsewhere have been Vjrought out 

 since then, and the facts as we know 

 them at present may probably be in- 

 terpreted somewhat in this way. 



The butterflies, which are far more 

 numerous in the late autumn than at 

 any other time, seek vvinter quarters to 

 hibernate, but with very rare excep- 

 tions, north of the natural division line 

 of the Canadian and Alleghanian fau- 

 nas, and even to a considerable distance 

 to the south of this, possibly sometimes 

 throughout the entire district of New 

 England, every single specimen per- 

 ishes. Now and then an old and bat- 

 tered female may be found in the month 

 of May, but we have actually on record 

 as far as I can discover but two or tliree 

 instances of this, and one of these is not 

 specific. A female much worn and 

 faded was found May 12 at Amlierst by 

 Professor Parker, and in another year 

 the butterfly was found by Mr. W. D. 

 Marsh on May 15 and May 21 at the 

 same place ; while Mr. Caulfield speaks 

 in general terms of the appearance of 

 butterflies in Montreal in Mav. In the 



