38 BULLETIN 737, U. S. DEPARTMENT OF AGRICULTURE. 



Although there are certain objections to the method, such as loos- 

 ening the wrappers of fine cigars by sudden changes in temperature, 

 danger of injury from "sweating" on removal from cold storage, 

 and injury to quality from too rapid aging, it has certain advan- 

 tages and in some cases may be found more desirable than other 

 methods of treatment. When care is taken to prevent " sweating," 

 it is evident that the exposure of manufactured or leaf tobacco in 

 cold storage is not more apt to produce injury than would be the ex- 

 posure of the same material to low temperatures during the winter. 



In determining the effect of cold-storage temperatures upon differ- 

 ent stages of the tobacco beetle, experiments were conducted during 

 1913 and 1914 at Richmond, Va. The temperatures available for 

 most of the experiments ranged from 12° to 16° F. At the laboratory 

 an automatically regulated incubator heated by an electric current 

 was used in rearing the beetles for experimental work and for hold- 

 ing the material used in the tests after it had been removed from 

 the cold-storage room. By this means the proper temperature and 

 degree of moisture favorable for the development of different stages 

 of the beetle could be kept constant. A large quantity of infested 

 manufactured tobacco of different kinds was secured from dealers 

 and manufacturers. In many of the experiments the exposure to 

 cold was made with the tobacco in original packages. Tobacco found 

 slightly infested was kept in the incubator and eggs or other stages 

 of the beetle placed in it until the degree of infestation desired 

 for the experiments was obtained. Experiments were made with 

 eggs on the tobacco or cigars on which they had been deposited, and 

 also, for convenience in making examinations, with the eggs in 

 glass-covered cells on microscope slides. 



The results of some of the experiments made by the writer dur- 

 ing 1913, and by Mr. S. E. Crumb and the writer during 1914, are 

 given in Table IV. 



