BIOLOGY OF TOBACCO MOTH AND ITS CONTROL 35 



guards provided to keep persons or domestic animals away. When 

 the warehouse is opened for ventilation, a minimum of 12 hours 

 should elapse before any one is permitted to enter. In moist weather 

 this period should be extended. A trained fumigator should then 

 inspect the warehouse and notify the personnel when it is safe to 

 resume work. 



If a person should be overcome by the gas used in fumigation he 

 must be taken into the fresh air immediately and a physician called. 

 In cases of poisoning with hydrocyanic acid gas fresh air should enter 

 the lungs in a manner similar to normal respiration. If the person 

 affected is breathing normally, it is often a satisfactory course to take 

 him into the open air and make him breathe the fumes of ammonium 

 carbonate, which will assist the victim in recovery. Fumigators 

 should have a supply of this chemical at hand for use as an antidote 

 for cyanide gas. If breathing has stopped or is irregular, artificial 

 respiration should be employed at once. One of the most efficient 

 means of promoting respiration artificially is the Schafer prone-pres- 

 sure method. A summary of this method of resuscitation has been 

 given in a recent circular of the United States Department of Agri- 

 culture (1, p, 52) and therefore will not be repeated here, but all 

 persons engaging in fumigation work should request the fumigant 

 manufacturers to supply the details of the process. All persons re- 

 sponsible for carrying out fumigations should be familiar with the 

 best known antidotes for gas poisoning and the proper technique of 

 artificial respiration. 



DISCUSSION 



The control recommendations given in this circular pertain to large 

 storage warehouses where the great bulk of cigarette-type tobaccos 

 are stored, often for long periods, in order to allow the tobaccos to 

 ferment prior to manufacture. Under these conditions the only fumi- 

 gant found satisfactory in tests was hydrocyanic acid gas. This gas 

 was not explosive or inflammable at the concentration found to be 

 effective, and its use was approved, under prescribed safeguards, by 

 fire insurance companies. Carbon disulphide was found to be a satis- 

 factory fumigant for tobacco at atmospheric pressure, but when fumi- 

 gating sections of storage space containing from 150,000 to 200,000 

 cubic feet each, the quantity of this fumigant required was so great 

 that a real fire hazard was involved. The majority of fire insurance 

 companies object to the use of carbon disulphide where the risk is 

 so great. 



Since it is not feasible to move the vast stores of cigarette-type 

 tobaccos through specialized apparatus, such as steel chambers, for 

 fumigation in partial vacuum, or into rooms constructed especially 

 for fumigation at atmospheric pressure, the writers attacked the prob- 

 lem of control in the warehouses. It proved feasible to work out a 

 fumigation schedule according to which applications of gas can be 

 made at times when the maximum population of moths are vulner- 

 able. This principle of insect control has been applied for many 

 years in economic entomology, and for nearly all insecticides, except 

 in the field of fumigation. It is rarely possible to obtain a complete 

 elimination of insects by the fumigation of large quantities of stored 

 products under the conditions usually found in factories and ware- 



