Potato Insects and their Control 173 



rapidly after hatching and much harm is often done before 

 one is aware of it. With fifty gallons of water, if the poison 

 is to be used alone, or of bordeaux mixture, use three to 

 fiv'e pounds of arsenate of lead or one pound of paris green, 

 and add two pounds of quicklime to prevent burning. 

 One pound of paris green to the acre in either water or 

 bordeaux mixture is ordinarily recommended. Growers 

 should be warned against the use of excessive quantities of 

 paris green because it burns and injures the vines if put on 

 too strong. Arsenate of lead has the advantage of adher- 

 ing to the vines and is only slightly washed off by rains. 

 After long-continued rains, the vines may often be seen 

 to be grayish in color because of the arsenate still clinging 

 to them. When these poisons are applied with water, 

 whether with or without bordeaux mixture, some provision 

 must be made to keep them constantly agitated so that 

 they will not settle to the bottom of the spray tank. 



Flea-beetle {Epitrix cucumeris) (Fig. 11) 



This is a leaf-eating insect. There are several kinds of 

 flea-beetles which are troublesome to potatoes, the one 

 named above being the most common. In the South the 

 tobacco flea-beetle {Epitrix parvula) and the eggplant 

 flea-beetle (Epitrix fvscula) do considerable damage. 

 Another larger, more elongated form, known as Systena 

 hudsonias, has been found to cause considerable damage 

 in the North. 



These flea-beetles all belong to the leaf-chewing class. 

 The adult beetles frequently do much damage to the 

 potato crop, but being so small, less than one-twentieth 

 of an inch, they are often not seen. They are black and 

 jump when alarmed, which also makes it difficult to see 



