GREENHOUSE AND COLD FRAME FUMIGATION 139 



The insects present were green fly, mealy bug, and 

 Fuller's leaf beetle. The plants were coleus, azaleas 

 in bloom, heliotrope, ferns, hoya, jasmins, polygala, 

 hibiscus, ericas, orange trees, camellias, cinerarias, and 

 oxalis. The temperature went below 50 F. No 

 plants were injured. Part of the green flies were 

 killed, but mealy bug and leaf beetle were not injured. 



Another trial was made in the camellia-room just 

 mentioned a few days later with gas generated from 

 one ounce cyanide to 2,000 cubic feet of space. The 

 exposure was continued throughout the night. No 

 plants were injured. The green flies were all killed, 

 but only a few of the mealy bugs were destroyed. 



A few days later another test was made in the same 

 room, using one ounce cyanide for each 1,000 cubic 

 feet. The temperature of the room was slightly above 

 50 F. With the exception of heliotrope and coleus, 

 the plants were the same as used in the two previous 

 tests. All the mealy bugs were destroyed. It would 

 seem from these tests that the gas can be used in a 

 greenhouse, under such conditions, generated from one 

 ounce cyanide in 1,000 cubic feet of space, with good 

 results upon the common mealy bug. 



Many other tests were made, including the vege- 

 table house. The cyanide was used at the rate of one 

 ounce for each 3,000 cubic feet of space enclosed. The 

 temperature was about 56 F. The plants fumigated 

 were lettuce, radishes, papyrus, smilax, cinerarias, and 

 kale. The lettuce and cinerarias were badly covered 

 with green fly. Nearly all green fly was killed, even 

 under the lower leaves of the lettuce which had com- 

 menced to head. There was no injury to plants. 



