INDUSTRIAL FUMIGATION AGAINST INSECTS 



49 



Federal meat-inspection regulations 8 require that permission for 

 each fumigation be obtained from the Federal meat inspector. 



Cheeses that are protected by an unbroken layer of paraffin can be 

 safely fumigated with hydrocyanic acid, but, owing to the danger of 

 their absorbing large quantities of the gas, unprotected cheeses should 

 be removed from a warehouse that is to be fumigated. 



For the treatment of small quantities of cured meats, or cheeses, a 

 fumigation vault or other tight container is recommended. Carbon 

 disulfide at the rate of 10 pounds, ethylene oxide at the rate of 2 

 pounds, or the ethylene oxide-carbon dioxide mixture at the rate of 

 20 pounds per 1,000 cubic feet of space can be used for a period of 

 24 hours. 



Figure 36. — Interior of tobacco storage with tobacco stored in hogsheads. 



Stored Tobacco 9 



Tobacco that is held in storage (figs. 36 and 37) often becomes in- 

 fested with the cigarette beetle (Lasioderma serricome (F.)) or the 

 tobacco moth (Ephestia elutella (Hbn.)). If the infested tobacco is 

 held in closed storage, fumigation with hydrocyanic acid gas is the 

 most effective means of preventing further loss from insect attack. 



Since the fumigants will not ordinarily penetrate tobacco hogsheads 

 in killing concentrations deeper than from 3 to 6 inches, fumigations 

 in warehouses should be timed to correspond with the emergence of 

 the broods of insects. From May to November, when tobacco insects 

 are normally abundant, it is desirable to suspend boards covered with 



8 U. S. Department of Agriculture, Bureau of Animal Industry, Service and Regulatory 

 Announcements, January 1921, p. 3, and August 1927, p. 62. 



9 More detailed information on the fumigation of tobacco warehouses will be found in 

 U. S. Department of Agriculture Circular 635, Control of Insects Attacking Stored Tobacco 

 and Tobacco Products. 



