8 



The Bulletin. 



many) have been in late winter and early spring, over half of all com- 

 plaints having been in the months of March, April and May. This 

 is also in accord with our observations. Of course when it attacks the 

 late crop its injuries must be in summer and fall. 



Fig. I. — Cabbage Louse. Showing how thickly the lice infest the lower surface of the leaves. 

 Slightly enlarged. (Photo by Z. P. Metcalf.) 



Distribution. — The cabbage louse seems to have a wide range. It is 

 destructive certainly throughout all of eastern and middle North Caro- 

 lina and probably throughout the western part of the State also, though 

 we have had fewer complaints from that section. Bulletins from Ken- 

 tucky and Michigan indicate that it is destructive in both of those 

 States, and it is the most important enemy of turnips in Ontario, 

 Canada. There is little doubt that it is present throughout the farm- 

 ing regions of the United States and Canada, for the Yearbooks of 

 the U. S. Department of Agriculture for 1907 and 1908 mention the 

 following places where injurious outbreaks occurred: "Wyoming, New 

 Mexico, California, Pennsylvania, Virginia, Florida, Texas, New 

 York, New Jersey, Ohio, and Canada. Our growers can see therefore 

 that this is not merely a temporary pest which will abide for a time 

 and then disappear, but it is a widely distributed and permanently es- 

 tablished pest, although it is worse in some years than others and in 

 certain seasons does not do serious injury. 



Life History, Habits, etc. — This insect, like all other plant lice, takes 

 its food by sucking the sap from the plant, its mouth being formed into 



