BUTTERFLIES OF VIRGINIA 



By AUSTIN H. CLARK 

 Curator, Division of Echinoderms, U. S. National Museum 



Very few butterflies are really rare, though many are seldom cap- 

 tured. If in any district you meet with a particular kind of butterfly 

 only at long intervals, it usually means that the individuals you find 

 are not really at home but have come from somewhere else not very 

 far away. 



Along the western border of Frederick County we had from time 

 to time noted individuals of the silky blue (Glaucopsyche lygdamus) , 

 the Virginia white {Pieris virginiensis) , and the Olympian marble 

 (Euchloe olympia) . The first two were so very scarce that we knew 

 they were more or less strangers to the region, and the last was not 

 very numerous. 



In the spring, when these butterflies are flying, it is often windy, 

 the wind coming from the west, so we figured that not far to the 

 westward, in Hampshire County, W. Va., we ought to find all three 

 of them in numbers. Visiting this region early in May, in company 

 with Mr. and Mrs. Ernest L. Bell and Dr. Walter S. Hough, we 

 found them all, as we had expected. 



The little silky blue flies very fast and keeps very near the ground 

 so that it is not easy to capture on the wing — and besides, you do not 

 often see it. But we found that its food plant in this region is the 

 Carolina vetch {Vicia caroliniana). If you simply stay near a patch 

 of this plant one of these butterflies will come to it every few minutes. 

 By this method you can in a short time gather all you wish. This is 

 generally regarded as a rather scarce little butterfly, but we found it 

 common enough. 



The Virginia white we found in damp low woods near a stream. 

 It has a languid flight and is by no means as energetic as the Euro- 

 pean cabbage white {Pieris rapae). It keeps always in the woods, 

 whereas the cabbage white keeps to the open country. We did not 

 find it very common ; as all the individuals captured were worn and 

 broken we judged that its season was almost over. Probably a week 

 or two earlier it would have been more numerous. 



The Olympian marble was very common on the higher portions of 

 the hills and ridges. In fact, one or more were almost always in 

 sight. On looking over the series of nearly 40 that we captured on 



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