THE POTATO TUBEE MOTH. 51 
QUARANTINE. 
Quarantine as a method of keeping out the tuber moth has 
attracted considerable attention in the Western States in recent 
years. A quarantine of one district against another when the 
tuber moth is established in both places is of little value, as the 
numbers of this insect in any one year are not influenced as greatly 
by its numbers the preceding year, or by any that might be introduced, 
as by food and climatic conditions. The great interstate shipment of 
potatoes throughout the West proves that the potato question is a 
factor which affects many of the people living in those States, and 
a hasty or ill-advised quarantine might cause losses which would 
more than offset any advantages to be gained from it. 
In conclusion it should be said that while the tuber moth is always 
a menace in warmer climates, it is by no means a fatal potato pest, 
and its damage, if not totally eliminated, can at least be minimized 
by rational farming methods and a knowledge of the habits of the 
insect. For this reason whenever there has been an outbreak of the 
moth in a new district the conditions 1 in this district should be studied 
and means devised to prevent a recurrence of injury. 
" SUMMARY. 
(1) The tuber moth injures the potato by destroying the leaf 
surface and tunneling in the substance of the tuber. 
(2) Its life history is variable, but in southern California all the 
stages exist at all times of the year. 
(3) The numbers of the insect should be reduced by practicing 
good farming and leaving no tubers exposed for the insect to work on. 
(4) Potatoes should be harvested and marketed as rapidly as possi- 
ble, unless the grower has facilities for storage and is prepared to 
treat the potatoes if necessary. 
(5) Once the tubers become infested the best way of ending the 
damage is to fumigate with carbon bisulphid, using 2 pounds to 1,000 
cubic feet of air space (measured before storing the tubers) and allow- 
ing 48 hours for fumigation. 
(6) Clean or uninfested potatoes should be kept away from the 
moth. 
(7) Potatoes should never be left in the ground after they are 
ripe and where the soil is dry. 
(8) When tubers are infested and facilities are lacking for storing 
in bins, the progress of infestation can be checked by holding the 
potatoes in cold storage. The temperature should be about 37° to 
40° F. This should be adopted only as a temporary method in 
keeping potatoes from deteriorating in value while they are being held 
for a rise in price. 
i This refers especially to various methods of storing potatoes. 
