THE POTATO MOTH. 
19 
hours. In the annihilation of the egg and pupa, however, using 
either of these amounts of carbon bisulphide per unit of space, 
the fumigation period must not be less than 48 hours, and to 
ensure complete destruction of these life-forms the application 
of a second fumigation four to six days after the first is necessary. 
The selection of the interval between the application of the first 
and second fumigation depends on the fact that any eggs or 
pupae which may have survived the initial fumigation are either 
approaching the larval or moth stage respectviely and are thus 
readily destroyed. 
In an experimental study of the influence of carbon bisulphide 
fumigation on the vitality of the tuber buds, the culinary and 
storage qualities of the tuber and the results of planting fumigated 
“ seed ” tubers, the author reports that sound, infested, and 
uninfested tubers may be intermittently fumigated with 1-2 lbs. 
of carbon bisulphide per 1 ,000 cubic feet of space for a period of 
48 hours two, three or four times without causing injury to the 
tuber buds or impairing the storage and edible qualities of the 
tuber. 
