CONTROL OF INSECTS ATTACKING STORED TOBACCO 37 



31) may be omitted and the others timed solely for controlling the 

 cigarette beetle. In warehouses storing tobacco primarily for do- 

 mestic manufacture, where the necessity for daily access to the building 

 in order to withdraw tobacco for manufacture sometimes delays fumi- 

 gation, two applications properly timed may give satisfactory control. 

 The following control program is recommended for closed ware- 

 houses : 



1. Install insect traps in tobacco warehouses prior to the emergence 

 of the spring brood of tobacco moths. (In Virginia and North 

 Carolina this date is about April 15.) 



2. Fumigate two to four times annually, as discussed above. 



3. For light infestations apply at each fumigation a dosage of 10 

 ounces of hydrocyanic acid per 1,000 cubic feet and for larger popu- 

 lations use 16 ounces per 1,000 cubic feet, with an exposure of 72 hours. 



4. In the warehouse fumigation of tobacco the gas should be 

 applied by a person trained especially for this work. Tobacco 

 companies should employ the services of a licensed pest-control 

 operator or train an employee especially for handling this 

 important work. 



5. In warehouses containing flue-cured tobacco moth populations 

 should be kept down by supplementing fumigation with weekly 

 applications of pyrethrum powder, as described under Control in 

 Open Warehouses. 



In open warehouses weekly applications of pyrethrum powder are 

 recommended for control of the tobacco moth. The powder should 

 be applied with a power duster at the rate of 3 ounces to each 1,000 cubic 

 feet of space not occupied by tobacco, as described under Control in 

 Open Warehouses. Weekly applications should begin as soon as trap 

 catches show that moths are active in the spring, usually early in May, 

 and they should be continued through September. The application of 

 pyrethrum powder does not provide satisfactory control of the cigarette 

 beetle. 



VACUUM CHAMBERS 



The principal uses of vacuum fumigation in the tobacco industry 

 are in the treatment of tobaccos en route from storage to the manufac- 

 turing plant, imported cigarette tobaccos upon their arrival in this 

 country for storage, and hogsheads of flue-cured tobacco at the time 

 of export or when placed in storage. 



Infested leaf tobacco is one of the principal sources of infestation 

 in the factory when it is removed from storage for manufacture. 

 If not eliminated the insects will spread over the factory and the 

 adults will lay eggs on the manufactured products. If all flue- 

 cured and imported cigarette tobaccos are fumigated in vacuum 

 before being brought into the factory, the danger of infestation in 

 the finished product is greatly lessened. 



The imported cigarette tobaccos brought into this country are 

 grown in the region surrounding the Mediterranean Sea, principally 

 in Greece and Turkey. Infestations of the cigarette beetle and the 

 tobacco moth are not uncommon in these tobaccos, and large popula- 

 tions develop unless checked by fumigation. Infested lots of these 

 tobaccos should be fumigated in vacuum upon arrival in the United 

 States and again when removed from storage for manufacture. 



