700 THE BUTTERFLIES OF NEW ENGLAND. 



and the under surface of sticks on the ground in their moultings or during 

 storms ; but at other times always exposed to full view, when their brilliant 

 color and active movements make them very conspicuous ; neither do they 

 seek protection by feeding at night. Their only sensitiveness to danger 

 is shown by the readiness with which they coil up and drop to the ground, 

 when the plant on which they are feeding is jarred. 



In New England, the caterpillar moults once only in the spring before 

 the final change to chrysalis ; Mr. Edwards, however, states that in the 

 south it moults twice ; moreover, he remarks that on opening some of the 

 wintering webs, presumably in the autumn, he invariably found a small 

 percentage of larvae which had not passed the third moult. If this condi- 

 tion existed through the winter, there would of course be one additional 

 change of skin for those which had been backward the previous year. All 

 that I have seen of them leads me to the belief that there is but a single 

 spring moult in New England before the final change. 



The caterpillars wander vigorously for pupation, hurrying as if their 

 lives depended on their reaching somewhere before the final change. Yet 

 somehow they do not seem thereby to disperse widely, for several may be 

 found hanoino; on the same bush or fence rail and Mr. Edwards once had 

 half a dozen brought him "suspended by one button like a string of fish.'' 



Life history. The insect is single brooded ; the hibernating cater- 

 pillars attain their growth in May and the chrysalids hang for from four- 

 teen to eighteen days, whether in New England or V^irginia ; the earliest 

 butterflies appear in the southernmost part of New England at the very 

 end of May or in the first days of June ; about Boston they are seldom 

 seen before the 1 2th of June and they become abundant a very few days 

 after their first appearance, although they continue for some time to emerge 

 from the chrysalis. Mr. Emery even reports taking one of the hibernating 

 caterpillars about Springfield as late as July 4. On the other hand I once 

 had a larva found near Boston change to chrysalis as early as May 19 : it 

 was, however, parasitized ; yet Mr. Bruce says he took parasitized larvae 

 at Brockport, New York, on June 1, and that they "kept on feeding two 

 weeks longer than the healthy subjects." In the White Mountain region 

 they are not much later than about Boston, for I have found them in abun- 

 dance on June 17. Toward the southern extremity of their range, ac- 

 cording to Mr. Edwards, they make their advent by the IStli or 19th of 

 May. They are on the wing usually about four weeks, and worn speci- 

 mens may be found a few days longer. By the loth or 20th of July they 

 have usually disappeared even in the northern parts of New England. 

 They appear to lay their eggs about three weeks after their first appear- 

 ance, — between the 5th and 15th of July in the latitude of Boston. 

 These hatch in nineteen or twenty days, the caterpillars grow very slowly 

 (Edwards speaks of their changes in West Virginia as rapid), and 



