22 



INJURIOUS INSECTS 



We notice only three of the species, as these will serve to 

 indicate the habits of the whole genus — which eyery 

 farmer should be familiar with, so that he may be able 

 to recognize and destroy such dangerous foes. 



THE RAPE BUTTERFLY. 

 {Pieris rapce, Schrank.) 



This insect has been the occasion of some little specula- 

 tion and great interest to our New England and Canadian 

 entomologists, inasmuch as it has been introduced to 

 this country from England, and is probably one of the 

 most perfect instances on record of any insect being im- 

 ported from one country to another and becoming com- 

 pletely naturalized in its new quarters. There does not 

 seem to be the slightest doubt that this is the English 

 species. It was probably introduced in 1856 or 1857. 

 It was first taken in Quebec in 1859, and in 1863 it was 

 captured in large numbers by Mr. Bowles in the vicinity 

 of that city. As the eggs are laid on the under sides of 

 leaves, it was probably introduced in this form, the re- 

 fuse leaves being thrown out of some ship, after which 

 the larvae hatched, and, finding themselves in the neigh- 

 borhood of their food, ate and flourished. Being, more- 

 over, hardy little fellows, they were perfectly able to en- 

 dure a change of climate. In 1864 it had spread about 

 forty miles from Quebec as a center; in 1866 it was taken 

 in the northern parts of New Hampshire and Vermont; 

 in 1868 it had advanced still further south, and was seen 

 near Lake Winnipesaugee; in 1869 it was taken around 

 Boston, Mass., and a few stray specimens in New Jersey. 

 Since that time it has spread over a wide range of coun- 

 try. The larva and pupa seem to have an unusual power 

 of accommodating themselves to circumstances — for in- 

 stance, Mr. Curtis, in his ''Farm Insects of England," 



