174 The Potato 



them. The result of their depredations will be found in 

 the many small holes which may be noticed in the leaves 

 of the young potato plants, and in the lessening of the 

 crop on this accoimt. These many small holes make 

 excellent starting places for many diseases to get a foot- 

 hold to injure the plant. The beetles stay mostly on the 

 under side of the leaves and are not seen, their presence 

 being detected only by their work. The larvae occasion- 

 ally do injury by mining into the 

 tubers and cause pimply potatoes. 

 During the hot, dry summers, 

 especially, they often become the 

 worst enemies of the potato. The 

 insects very often congregate in 

 a b such numbers that the leaves of the 



Fig. 11. Flea-beetle, plants appear almost black with 

 en arge . them. Young potatoes and newly 



set tomato plants frequently have their leaves so badly 

 eaten that they shrivel, and the tomatoes may die. 



The life histories of the different flea-beetles are prac- 

 tically the same. The adult insects live over winter under 

 leaves and rubbish and appear during the latter part of 

 May and first of June. As soon as they come out, they 

 lay eggs near the roots of the potatoes or of weeds related 

 to them. The larvse mine into the roots ; and when full 

 grown, they pupate and later emerge as adult flea-beetles. 

 In some sections, particularly in Colorado, the greatest 

 damage is done by the larvae, which are tiny white grubs 

 about a quarter of an inch in length. They frequently cut 

 into and destroy the young tuber stems of the potato and 

 prevent a regular setting of the crop. 



One brood of potato flea-beetle appears yearly in the 

 North and two broods in the South, the second ordinarily 



