22 
vals will be found effective in destroying the flour moth in its dif- 
ferent stages, unless the mill or other building happens to be a heated 
one. The moths are not apt to breed to any extent during the 
winter, hence there are few eggs to deal with at this time. In north- 
ern mills which have been much affected by this insect, especially in 
Minnesota and Canada, where the temperature is frequently 20° to 
30° F. below zero, this method of destroying the pest has been pur- 
sued with most excellent results. Speaking generally, it should be 
practiced wherever the temperature warrants the process. There are, 
of course, southern mills, e. g., in Kansas and Texas, where this 
‘method would not meet with much success. 
Approved: 
James WILsoN, 
Secretary of Agriculture. 
WasuHineTon, D.C., January 22, 1910. 
[Cir. 112] 
O 
