INSECTS IXJURIOUS TO THE POTATO. 241 



will be rapid rotation of crops, until the infested land has 

 become clear of them. 



INJURING THE STALK. 



The Potato Stalk-borer {Tricltoharis trinoiata Say.). 

 In some sections this insect has rivaled the famous 

 Colorado Potato-bug in the damage it has inflicted upon 

 potato-yines. It was recorded in Iowa as badly damaging 

 the crop there in 1890, and was found by Dr. Eiley in 

 Missouri as early as 1869. The beetles were first noted in 



Fig. 13G. — Potato ^talk-horer (Trichoharis tri?wtaia). Larva, pupa 

 and adult. (After J. B. Smith.) 



New Jersey in 1895, and during the last few years have 

 been doing serious injury to the fields of northwestern 

 Maryland. 



Life-history. — The grubs, which bore into the stalk of 

 the vines, are the larvae of some small ashen-gray beetles 

 which appear early in spring and into June. These beetles 

 are about one-fourth of an inch long, with a long, black 

 beak or snout, and are marked at the base of the wing- 

 covers by three black spots which give the insect its specific 



