38 



'Test No. 7: 



August 28, 1902. Dipped three apples in whale oil soap mixture; 1 pound of 

 soap to eaeh gallon of water. After removal they were washed with water. 



August ;31, 1902. Plenty of young on all apples. 



September (i, 1902, Plenty of young on all apples: few old females dead. 



September 15, 1902. All apples thoroughly infested. 

 Test No. S: 



August 38, 1902. Check lot of infested apples. Scales breeding profusely 



September G, 1902. All apples thoroughly infested. 



September 1"), 1902. All apples thoroughly infested; badly rotted. 



Ill the above tests with whale oil soap mixture it will be noted that 

 many of the mature females were killed, but in all cases where the 

 fruit was washed after treatment a large number of young developed. 

 When used at the rate of 1 pound to each gallon of water and treated 

 as in test No. 7 few of the scales were killed. The most successful 

 treatment was in test No. 4, where 2 pounds of soap was used to each 

 gallon of water, no washing being given the fruit, but even in this 

 case one or more scales survived, as two of the three apples were very 

 slightly infested at the close of the experiment. It is a difficult mat- 

 ter to reach every scale even by this method, as some time is required 

 for the liquid to penetrate those that are hidden beneath the calyx 

 lobes of the apple, which seems to be a favorite place for the young 

 lice to settle. 



A comparison of the method of dipping the buds and that of fumi- 

 gation shows that ihe latter is more effective and leaves them in bet- 

 ter condition for use. The cost of either measure is so small that it 

 is scarcely worth considering when the benefits to be derived are taken 

 into account. A little more time is required for fumigation, but the 

 results are certain. 



I>uds may be injured by exposing them to the action of the gas for 

 too long a time. Mr. Cole writes me that he has injured well-matured 

 plum buds this season by allowing them to remain exposed to the gas 

 for three or four hours. In all cases of injury the bark on the imma- 

 ture parts of the bud sticks was discolored. lie further states, "I 

 used cyanide, 1 ounce to 100 cubic feet, fumigated in the box we made 

 last year. We uspd the buds that showed no discoloration, and where 

 buds have been exposed but forty minutes my men have made no com- 

 plaint of injury." 



SUMMARY. 



The results of these experiments show that the fumigation of bud 

 sticks, using from three-fourths to 1 ounce of cyanide to each 100 

 cubic feet of space and exposing for forty minutes, is effective in 

 destroj'ing the San Jose scale and is not injurious to the buds. The 

 soap treatment, when used as in the experiments detailed above, is 

 not wholly effective, and if the sticks are washed after treatment it is 

 of little value as far as killing the scale is concerned. 



