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Experiment in screened, closed-type warehouses . --In 1948, 81 closed 
warehouses were sprayed weekly with pyrethrum in oil, and 40 were 
fumigated with hydrogen cyanide two or more times. These warehouses 
ranged in size from approximately 80,000 to 631,000 cubic feet, averaging 
about 300,000 cubic feet. The number of warehouses from which records 
were received varied from week to week because of factors such as 
geographical location and sale of tobacco, but averaged 73 sprayed and 
33 fumigated warehouses. 
The object of spraying was to kill the adult insects before they could 
lay eggs. Spraying was begun therefore as early in the spring as any 
appreciable nrmber of adults appeared. Fumigation was scheduled to 
follow immediately after the peak of emergence (of adults) of each brood, 
except that a warehouse containing only tobacco of the previous year's 
crop was scheduled for fumigation as early in the spring as a weekly 
trap catch of 50 moths was obtained. The average weekly trap catches 
of tobacco moths are shown in table 3. In only 3 of 28 weeks was an 
appreciable trap catch of moths taken in the sprayed warehouses, and 
these 3 weeks were at the beginning of the season. The spray gave much 
better control of the tobacco moth than the fumigations. 
These 81 warehouses contained over 120 million pounds of flue-cured 
tobacco. No effect of the spray on the taste, aroma, texture, or aging of 
the tobacco was detected. 
Control of Cigarette Beetles in Screened, Closed- Type Warehouses 
Late in the summer of 1945 a heavy infestation of cigarette beetles 
developed in two warehouses of Turkish tobacco at Richmond, Va. One 
warehouse was sprayed with pyrethrum in oil weekly from July 26 until 
September 27, a period of 10 weeks. The spray contained 0.5 percent of 
pyrethrins, except that on August 17 and 24 twice that strength was used. 
Results of this experiment are shown in table 4. The infestation of 
cigarette beetles was brought under control. 
In 1948 seven warehouses at Norfolk, Va., were sprayed weekly from 
April 6 to July 17 with oil containing 0.2 percent of pyrethrins to control 
the tobacco moth. A light infestation of the cigarette beetle developed in 
July, and the spray was changed on July 24 to one containing 1 percent 
of pyrethrins. Spraying was stopped on October 21. 
Table 5 shows that the infestation was held to a very low level. 
Eight warehouses at Wilmington, N. C, also showed a light infestation 
of the cigarette beetle in June and July. These warehouses were fumi- 
gated twice with hydrogen cyanide (16 oz. per 1,000 cu. ft.)--on April 28 
