POTATO INSECTS 



155 



When disturbed the nymphs run in all directions but the adults 



can jump quickly and fly away, often rising in swarms as one 



walks through an infested field. About a month is required 



for the completion of the life cycle. There 



are three generations of the insect a season 



on the potato. In the fall the adults find 



their way back to the apple and there 



deposit the winter eggs in the bark of the 



smaller branches, just below the epidermis, 



two-year-old wood being most often selected. 



The position of the q^^^]^ is indicated by a 



low blister-like elevation of the bark about 



•gV inch in length and about half as wide. 



The apple leafh()})per has also been 

 reported as causing spots on the white 

 stalks of celery and as feeding on sugar- 

 beets and beans. It is rarely of sufficient importance on potato 

 to warrant special applications of insecticides. The nymphs 

 may be killed by si)raying with "Black Leaf 40" tobacco 

 extract as recommended for the control of the potato aphis. 



Fui. S9. — Tho i.pple 

 lenfhoppor, adult 

 (X 11). 



References 



Minn. Agr. Exp. Sta. Bull. 112, pp. 14r)-l()4. 1908. 



Jowa Agr. Exp. Sta. Bull. 111. 1910. 



Iowa Agr. Exp. Sta. Bull. ir,.^>, i)p. 394-400. 19ir). 



The l\rrAT() Stalk-Wep:vil 



Trichobaris trirwiala Say 



Throughout the northern states from New York to North 

 Carolina westward to Kansas, Nebraska, Texas and southern 

 California, j^otatoes are subject to the attacks of a small weevil, 

 the larva of which bores in the stalk. This insect has been 

 found most injurious in Kansas, Nebraska and Iowa, but more 



