28 CIRCULAR 3 7 3, TJ. S. DEPARTMENT OF AGRICULTURE 



A description of the fumigating house used, a discussion of the 

 operation of commercial fumigating houses, and details of fumigat- 

 ing under commercial conditions, are included. 



Large quantities of bananas are imported from the Tropics into 

 the city of Philadelphia, Pa. Refrigerator cars loaded in this city 

 Avhile Japanese beetles are abundant are subject to infestation, and no 

 cars destined for points outside the quarantine area can be moved 

 unless assurance can be given that no infestation exists in them. 

 Attempts to screen the passage between the fruit boat and the cars 

 proved unsuccessful. Severe injury occurred to bananas exposed to 



2 pounds of ethylene oxide under the conditions indicated above. 

 Tests have shown that all beetles can be killed with an exposure to 



3 pounds of calcium cyanide (50-percent cyanogen) per refrigerator 

 car of 2,600 cubic feet capacity, for iy 2 or 2 hours, with an initial 

 temperature of 80° F. inside the car. The powdered chemical is 

 spread in paper-lined wooden trays, which are placed on top of the 

 fruit. 



Tests with a number of compounds which produce hydrocyanic 

 acid gas indicated that toxicity to Japanese beetle grubs is dependent 

 on the amount of hydrocyanic acid gas produced and the rapidity of 

 its evolution, under similar conditions of exposure and temperature. 

 The compounds showing the highest degree of toxicity were those 

 containing liquid hydrocyanic acid absorbed in diatomaceous earth 

 or in wood-paper pulp. 



Tests with liquid hydrocyanic acid showed that both grubs and 

 adult beetles can be killed by a 2-hour exposure to 6 ounces of the 

 chemical per refrigerator car, the temperature inside the car being 

 75° F. at the start of the treatment. The liquid is introduced from 

 a portable drum into containers placed on the rack in the ice 

 compartment at each end of the car. 



The costs for calcium cyanide and hydrocyanic acid are approxi- 

 mately $3.45 and $0.37 per car, respectively. 



The amount of hydrocyanic acid absorbed by the bananas is not 

 more than 10 parts per million, practically all of which has disap- 

 peared 5 days after fumigation. 



Bananas were injured by dosages of 5 pounds of hydrocyanic 

 acid per 1,000 cubic feet. However, no injury to fruit when fumi- 

 gated with the recommended amount (6 ounces per car) has been 

 reported. 



Precautions to be observed while handling cyanide compounds are 

 included. 



LITERATURE CITED 



(1) Back, E. A., Cotton, R. T., and Ellington. G. W. 



1930. ETHYLENE OXIDE AS A FUMIGANT FOR FOOD AND OTHER COMMODITIES. 



Jour. Econ. Ent 23: 226-231. 



(2) Cotton, R. T., and Roark, R. C. 



1928. ethylene oxide as a fumigant. Indus, and Engin. Chem. 20: 80H. 



(3) Griffin, E. L., Neifert, I. E., Perrine, N., and Duckett, A. B. ^ 



1923. ABSORPTION AND RETENTION OF HYDROCYANIC ACID BY FUMIGATED FOOD 



products. U. S. Dept. Agr. Bull. 1149, J 6 pp.. illus. 



(4) Hinds, W. E. 



j 902. carbon BisuLPHiD as an insecticide. U. S. Dept. Agr. Farmers' 

 Bull. 145. 28 pp. (Replaced by Farmers' Bull. 799. 21 pp., 1917.) 



