POTATO INSECTS 157 



larv?e may infest the same stalk and often kill the entire plant. 

 When full-grown, the grub eats out an exit hole for the future 

 beetle nearly to the surface but does not penetrate the outer 

 bark. It then constructs a cell or cocoon of fibers stripped 

 from the wall of the burrow and then transforms into a creamy 

 white pupa about ^ inch in length. In Kansas the larvae 

 begin to pupate about the middle of July and in New Jersey 

 the last of the month but some do not reach maturity till early 

 fall and in a few cases have been known to enter the winter 

 in this stage. The insect spends from eight to fifteen days or 

 longer in the pupal stage. Although some of the beetles are 

 to be found in the stalks in early August, they do not usually 

 emerge until the following spring, but when the stalks are broken 

 open they may be forced to seek winter quarters elsewhere. 

 There is only one generation annually. 



Control. 



The potato stalk-weevil is best held in check by collecting 

 and burning the vines soon after the crop is dug. If this is 

 practiced regularly and if all solanaceous weeds in which the 

 weevils breed are reduced to a minimum by clean farming, 

 the pest can be prevented from doing any serious damage. 



References 



N. J. Agr. Exp. Sta. Bull. 109, pp. 25-32. 1895. 

 Kans. Agr. Exp. Sta. Bull. 82. 1899. 

 U. S. Div. Eiit. Bull. 33, pp. 9-18. 1902. 



The Common Stalk-Borer 



Papaipema nitela Guenee 



The common stalk-borer is generally distributed throughout 

 the United States and Canada east of the Rocky Mountains. 

 Although the insect is usually present in small numbers, oc- 

 casionally serious outbreaks occur locally. The borers attack 



