THE POTATO TUBER MOTH. 
49 
On an average the results show the value of the recommendations 
given for righting the tuber moth by culture. 
These may be stated as follows : 
(1) Plant as deep as practicable (5 to 6 inches). 
(2) Use ridge culture, i. e., ridge the rows (fig. 45). 
(3) Harvest as early as possible. 
(4) Harvest before the potato tops become so dry as to drive the 
partially grown larvae to descend and work on the tuber. 
In harvesting the tubers, several rules must be followed to keep 
the tubers from infestation : 
(1) The sacks should never be covered with potato tops, as the 
larvae leave these when they wilt, and enter the potatoes. 
Fig. 45. — Potato field showing careful hilling. Walker, Cal. (Original.) 
(2) The sacks should be sewed as soon as possible and hauled 
from the field. 
(3) Potatoes should never be left in the field or exposed to the 
moth overnight. 
(4) All cull potatoes should be gathered up within two weeks and 
either fed to stock at once or destroyed. If left in the field they are 
a menace to the neighbors, and to the grower himself, for the follow- 
ing crop. 
After the potatoes are harvested they should be marketed at once, 
unless the grower has storage facilities and is willing to take the 
trouble to treat the potatoes. 
While there are good reasons for destroying the potato vines yet 
there appear to be even better reasons for not doing so. Destroying 
the potato vines kills all stages of the tuber moth within, but it also 
