BUTTERFLIES OF THE DISTRICT OF COLUMBIA 165 



April 18 and 28. There are seven specimens from this region in the 

 National Museum. Of 4 males, 2 are labeled Cabin John, April, 

 1919 (D. H. Blake) ; 1, District of Columbia, April 27, 1885 (Schon- 

 born) ; and 1, Washington (W. Schaus). One female is labeled 

 April 21 (Schonborn) and another is labeled April, 1899. Mr. Shoe- 

 maker has specimens taken the last of April and first of May in Rock 

 Creek Park and in Arlington County, Va. 



Habits. — The orange tip, in marked contrast to all our other 

 pierids, is a woodland butterfly, keeping mostly among the trees, 

 though it is rather fond of flitting across open glades and for short 

 distances along the sides of woodland roads. While it is frequently 

 seen just at the border of woods, it will not venture out over open 

 fields. 



It is a very active little butterfly, and is seldom seen except upon 

 the wing. It flies in cool weather and also on cloudy days when the 

 other spring pierids are wholly inactive. It seems to pay little 

 attention to flowers. 



The orange tip flies about 2 feet above the ground with the wings 

 moving rapidly through a small arc, which gives the flight a peculiar 

 tremulous or fluttering aspect. The course is a slight and somewhat 

 irregular zigzag, much more marked in the males than in the females. 

 When the insect is alarmed the speed is much increased and the zig- 

 zag becomes more pronounced, while the butterfly usually rises to a 

 height of about 3 feet, or occasionally more. The flight of the 

 orange tip much resembles that of Pleris protodice, and in spring it 

 is possible to confuse the two when seen on the wing. 



Season. — The orange tip first appears in the last week in March, 

 and in a few days the males become common. The females appear 

 about a week later than the males, or in the first week of April. 

 Toward the end of April the females become numerous, and in the 

 first week in May they outnumber the males. By the end of the 

 first week in May only a few females are to be seen, and during the 

 second week in May the last of them disappear. 



In both sexes there is a regular progressive increase in size from 

 the earliest to the latest individuals. 



Notes. — Mr. Schonborn was the first to work out the life history 

 of this butterfly. In 1886 he supplied Mrs. Mary Peart with the 

 eggs, larvae, and food plant, from which material she prepared the 

 illustrations published by W. H. Edwards. Later, in 1888, he sent 

 eggs and plants directly to Mr. Edwards. He wrote to Mr. Edwards : 



I never found a larva in open fields, although the plant grows there in abun- 

 dance in large patches. I alvi^ays found them on isolated plants growing in 

 places sparingly covered by large oaks, hickories, cedars, and other trees. 



After the plant has gone to seed it utterly disappears, and the larvae never 

 pupate on the plants, but go to the trunks of the nearest trees and there change 



