BIOLOGY OF TOBACCO MOTH AND ITS CONTROL 



33 



Table 8. — Summary of receipts of hogsheads of tobacco which had been stored 

 for 1 year or more in other localities, Richmond, Va., 1932 





Dates of receipt 



i logsheads ' 



State from 

 which to- 

 bacco was 

 received 



May 1 to June 1 . . . . . - . 



Number 



32 



1G 



16 



816 



2, Hi 

 3, 1)24 



Virginia. 

 Do. 



June 2 to June 28, . _ ._ . . '' ... 



June 29 to Aug. 3 



Do 



Aug. 4 to Sept. 8 .... . _ . ._ . .. ... .. 



Virginia, 

 North 

 Carolina. 



Virginia, 

 North 

 Carolina, 

 Georgia. 



Sept. 9 to Oct. 31 



u Total 







1 Average contents, 1,000 pounds net. 



The 3,024 hogsheads (approximately 3,024,000 pounds) of old 

 tobaccos were not segregated in the warehouses, but were distributed 

 in the various sections according to grade of tobacco, in accordance 

 with regular warehouse practice. These old hogsheads came from 

 storage centers where there was known to be tobacco moth infestation, 

 and observations showed that some of the hogsheads contained moth 

 infestations when received. It was not feasible to open and inspect 

 these hogsheads upon receipt, owing to the cost of such inspection and 

 the interruption to warehouse procedure. Observations were occa- 

 sionally made, however, on lots of hogsheads, which showed that 

 some moth infestation was being brought into the warehouses in these 

 old tobaccos. It was concluded, for example, that most of the infesta- 

 tion shown by the light-trap indicators from August 4 to September 8 

 came from the 816 old hogsheads received in the warehouses during 

 that time. Likewise, the 2,144 hogsheads received from September 9 

 to October 31 provided most of the infestation which appeared on the 

 indicators during that period. This movement of old tobaccos into 

 warehouses is an important factor in evaluating results from periodic 

 fumigations of tobacco warehouses. It is often impractical to have 

 all hogsheads fumigated immediately prior to their being placed in 

 warehouses. This procedure would require specialized apparatus, 

 such as vacuum or atmospheric chambers, and would often interrupt 

 warehouse routine. 



COST OF THE CONTROL PROGRAM OF 1932 



Records were made of all expenditures for the fumigation experi- 

 ments in the warehouses, the results of which are shown in table 7 and 

 figure 22, including hydrocyanic acid, materials for sealing the ware- 

 houses, labor, and the service charges of a commercial fumigator. 

 The average cost per 1,000 cubic feet of space fumigated (total for 

 four fumigations) , using a dosage of 10 ounces of liquid hydrocyanic 

 acid, was 61.2 cents, and the average cost per hogshead of tobacco 

 protected was 9.8 cents. These costs were distributed as follows: 

 Hydrocyanic acid, 81.2 percent; materials for sealing, 4 percent; 

 labor, 6.3 percent; and services of a commercial fumigator, 8.5 per- 



