30 BULLETIN UNIVERSITY OF MONTANA. 



Butterfly— Known as cabbage butterfly; yellowish white, with apex 

 of fore wings black. Two black spots on fore wings and one on the hind 

 wings. Underneath, the apex of the fore wings and the entire surface 

 of the hind wings are pale lemon yellow. In the female two spots on 

 outer part of fore wings, in male only one. 



The larva feeds principally on cabbage. Its color is green like the 

 cabbage leaf, with a narrow greenish lemon yellow dorsal band. The 

 body is clothed with very flne short hairs. 



Distribution — This common species is an importation from Europe. 

 It reached Quebec in 1860; how, no one knows, perhaps in cabbage. By 

 1881 it had spread over the eastern half of the continent, from Hudson 

 Bay to Southern Texas. In 1886 it had reached Denver, and in 1884 had 

 reached the head waters of the Missouri. It now possesses the cabbage 

 fields from the Atlantic to the Pacific, "to the incalculable damage of all 

 who provide the raw material for sauerkraut." The injury done by the 

 caterpillar is estimated to amount to hundreds of thousands of dollars. 



It is probably to be found all over the state, and has been taken at 

 almost every place where collections have been made, at Missoula, Miles 

 City, Bozeman, Helena, University of Montana Biological Station at Flat- 

 head Lake, Mission Mountains. It does not seem as common as 

 P. protodice. Allen collected it at Dillon. 



THE MUSTARD WHITE. 

 Pontia nap! Linnnaeus. Fig. 27. 



1 2 



Fig. 27. Pontia napi, No. 1, var.pallida No. 2, var. acadica. 

 Butterfly— Expanse of wings, about 1.75 inches. In general shape 

 and appearance it resembles protodice or rapae. General color while, 

 with grayish vein markings, some with a dusky spot on the wings, or 

 dusky at the base of the wings. A Protean, cosmopolitan species, ex- 

 isting in many forms, the result of climatic and local influences, which 

 has a very wide distribution. The different forms are to be found from 

 Arctic America as far south as California on the west, and Michigan and 

 New England on the east. It is mostly represented in the regions farther 

 to the north. The typical form is found in Europe, rarely in NortTi 

 America, although Holland has specimens from the Pacific Coast region 



