CHAPTER VI 

 POTATO INSECTS 



The potato plant is a native of America and the insects 

 affecting it are, with few exceptions, indigenous to the New 

 World. In the East the most important potato insects are 

 the Colorado potato beetle and the potato flea-beetle. The 

 latter is treated on page 314. In California the potato tuber 

 moth has in some localities threatened the potato-growing 

 industry. Potatoes are especially subject to attack by blister- 

 beetles. These pests are discussed in Chapter XVI. 



The Colorado Potato Beetle 



Leptinotarsa decemlineata Say 



The genus to which the Colorado potato beetle belongs 

 occurs in greatest abundance in southern INIexico and Central 

 America and it is supposed that this species originated in that 

 region where it is now represented by closely related forms, 

 it had, however, migrated northward so that by the early 

 part of the last century it occupied a strip on the eastern slope 

 of the Rocky Mountains from Texas and New Mexico north- 

 ward to the Canadian boundary. The potato beetle was first 

 described by Thomas Say in 1824 from specimens collected 

 in the upper Missouri River Valley. The original food plant 

 of the insect was the buffalo bur, Solanum rostratum. When 

 the early settlers first began to plant potatoes in western 



142 



