r hat th> 
fumigations in holding down the inT -n of < 
948, ■ • >.-., S. ( i 5 at Wilm:- 
d with the cigarette beet 
at Char y with pyrethrum in oil. those at 
Wilmingt< •• fun. nd 4 of the storage .miga - 
three times if hydrogen cyanide was 16 to 20 ou: 
1,000 cubic feet. The pyrethrum-oil spray contained 0.2 p* of 
pyrethrins until May 4, when it was changed to a l-p< I 
6 shows that effective control was not obtained by i or fumif- 
tion, although the fumigation was the more effective. In both gro • 
warehouses a heavy infestation of the cigarette beetle had developed 
the late summer of 1947. This infestation had penetrated the tobacco so 
deeply that it was very difficult to control. 
Relative Cost of Spraying and Fumigation 
The cost of using pyrethrum-oil spray varied with the sti of 
ay used, the cost of labor, and the number of warehouses tr 
Of 78 warehouses sprayed under widely varying conditions in 1943, the 
cost per season ranged from $157 to $414 per warehouse and the 
.'. as $.'38 1 . 
Under comparable conditions of labor, the cost figures were <d 
sealing and fumigating 44 warehouses in 1948 A ; • d 
widely, but the estimated average cost per warehouse per furr. as 
$507. 
These figures are given in detail in table 7 It can b< 
cost of spraying was substantially less tfa fumu hydrogen 
0US6 was sj. mtrol I 
. roxim half tin f a single fun 
less than 
fun >n 
Summar 
• hruxn 
nd the 
■ 
11-194 
