(>6 



PSrCHE. 



[June iSSS. 



ther nortli tliau at any other point in 

 New England excepting in some in- 

 stances along the sea-board. 



My own collecting in New England, 

 where this butterfly is much less common 

 than further south, leads me to believe 

 that it is far easier to obtain it by search 

 for the caterpillar on the leaves o'i Ascle- 

 ■pias than by capture upon the wing; 

 and I should rather decide upon the 

 presence of butterflies in any particular 

 district by a search for plants of As- 

 clepias in suitable spots, than by watch- 

 ing for tlie butterflies ; so that the fail- 

 ure year after year to find such larvae 

 on young and tender plants in the very 

 spots which are invariabh' chosen by the 

 July butterflies whereon to deposit their 

 eggs is to me very strong proof that the 

 butterfly does not ordinarily exist in any 

 form during the early months of the 

 year in regions that I have searched. 

 Regarding the later broods it may be 

 added that the observations of Mr. 

 Marsh, who raised butterflies as late as 

 the latter half of October and even in 

 November, were made in part at least 

 upon housed larvae and that at this late 

 epoch of the year the transformations of 

 the insect are very much slower than 

 they are earlier in the season. Thus 

 Mr. Marsh himself states that the pupal 

 period in October is about three weeks. 



while in September it is only about a 

 fortnight. In midsummer it is about 

 ten days. 



Mr. Edwards, accepting a suggestion 

 of Mr. Marsh, further urges that the 

 failure to discover the hibernators in 

 the spring is due to their rarity in the 

 autumn and the latter from the fact that 

 in New England the fields are often 

 mowed for a second crop and that with 

 the hay great quantities of milk-weed 

 are cut down. But aside from the fact 

 that the larger part of the milk-weeds 

 inhabited by the caterpillars is found 

 by the side of roads and lanes and 

 in close vicinity to shrubbery, where 

 it is not disturbed by the scythe, there 

 is a single fact which renders this argu- 

 ment absolutely useless, viz., that the 

 imago is far more abundant late in the 

 season than at any other time in the 

 year, sometimes swarming to an exces- 

 sive extent and foimd in New England 

 in the same abundance that it is so often 

 found in the west. Yet so far as I have 

 been able to find from inquiries (unfor- 

 tunately not made at the time), in no 

 instance have hibernators been seen in 

 years immediately succeeding autumns 

 which have witnessed a vast profusion 

 of butterflies, nor have autumns of 

 great abundance been followed by 

 springs of plenty. 



