BUTTEEFMES OF THE DISTRICT OP COLUMBIA 125 



The occurrence of this butterfly in great numbers in areas from 

 which its food plant is wholly absent has previously been noticed. 

 It would seem that immediately upon emergence the insects seek a 

 locality abundantly supplied with suitable flowers where they may 

 sorffe themselves with food with the minimum of effort. 



Incidentally it may be mentioned that these butterflies were not the 

 only arthropods to appear after the rain. Wood ticks and chiggers 

 unexpectedly showed up, though in small numbers, the former to the 

 extent of about 4 per cent of their early-summer frequency. 



On September 23 there was a large flight of Alabama argillacea 

 m the city of Washington. Whether this flight had any relation to 

 rain south of this area remains to be determined. 



In spring this butterfly is very scarce. In the last half of April 

 and early in May females are sometimes to be seen along the river, 

 usually flying a foot or so above the ground. They are very incon- 

 spicuous, their faded colors harmonizing with the color of the ground 

 over which they fly. 



On April 28, 1931, Dr. and Mrs. Torsten Gislen reported one 

 flying westward along the Virginia shore of the Potomac rather 

 high in the air, and when on the Maryland side of Great Falls on 

 May 9, 1931, in company with Miss Dorothea Bates, Miss Doris M. 

 Cochran, and Dr. Herbert Friedmann, I saw one flying slowly up 

 the river before the wind about 20 feet above the cliffs just as it 

 flies in the same region in the autumn. 



The habits of this butterfly in spring, therefore, seem not to differ 

 from the habits at any other season. The egg-laying females fly 

 along hunting for the food plant in the same way in the spring as 

 later in the year. They fly lower because the grass has only just 

 begun to grow. The individuals seen by Doctor and Mrs. Gislen 

 and by myself high in the air over the river banks were of unknown 

 sex, but evidently they were traveling quite in the same way that is 

 so characteristic of summer and autumn individuals. 



Notes. — In freshly emerged individuals the entire upper surface 

 of the wings, especially of the fore wings, shows in the sunlight a 

 beautiful violet iridescence, which is particularly noticeable in the 

 darker individuals and on the comparatively dark fore wings of 

 females. This iridescence soon disappears, leaving only the bright 

 steely reflections from the black veins. 



There is considerable variation in the ground color of the under- 

 side of the hind wings, especially in the males. Females sometimes 

 have the cell of the fore wings below with a band of white, narrowed 

 in the middle, across the outer end. They rather frequently have a 

 smaller or larger buff spot on both surfaces (whitish and larger 

 beneath) in the interspace between veins M3 and M2 near the black 

 border. The ground color of the upper surface varies considerably, 



