FUMIGATION OF FRUIT TO DESTROY JAPANESE BEETLE 



19 



acid in the usual ratio of 1 part sodium cyanide to iy 2 parts of 

 sulphuric acid and 2 parts of water. 



Japanese beetle larvae were used as an index of toxicity, as they 

 were procurable over a long period. All tests were performed in 

 the fumigating house described in detail on page 2. The larvae, 

 confined in wire cages, were placed in the house prior to the introduc- 

 tion of the fumigants. Compounds nos. 1 to 4 were spread out upon 



Figure 14. 



-Side view of car showing trays containing calcium cyanide on the bunches of 

 bananas. 



paper placed on the floor, while compound no. 5 was used according 

 to the regular " pot method." At the conclusion of each test the 

 larvae were removed for observation, the residues from the fumi- 

 gating materials were discarded, and the house was aired thoroughly 

 for 2 days before the next test. 



For making preliminary comparisons the writer decided to use as 

 standard conditions a volume of 1,000 cubic feet (the volume of the 



