38 



first of January and the time when the buds begin to swell. Dur- 

 ing this period pure kerosene may be used under certain conditions 

 with success. Kerosene will kill every scale which it touches, 

 but, unless used in experienced hands, it is likely to kill the tree 

 also, even during the late winter months, hence should be used 

 with caution, and, as there are other and safer treatments, its use 

 in general should be avoided. If it is desired to try it, however, 

 the following suggestions should be closely followed : — 



1. Use pure kerosene in January, February or March only. 



2. Use the finest nozzle to the spray pump which can be ob- 

 tained. 



3.- Stop spraying any portion as soon as it is wet. 



4. Spray on a bright day, when a slight (not strong) breeze is 

 blowing. 



Crude Petroleum. 



This substance has been recommended as an insecticide for 

 scale insects by Dr. J. B. Smith of New Jersey, where it was 

 first tried in 1898. While perhaps not beyond the experimental 

 stage, as yet, it seems to promise well if precautions be followed 

 in its use. Some of the conclusions drawn from experiments with 

 it are : — 



1. Treatment should be made in January, February or March. 



2. Crude petroleum is not adapted to summer use. 



3. It kills the scales wherever it comes in contact with them. 



4. It may be used pure, but a more even distribution is obtained 

 by mixing forty parts with sixty of water by means of a two-tank 

 pump, such as the " Kerowater." Do not apply too much. 



5. Use a very fine nozzle. 



6. Spray on a reasonably calm day, when the trees are dry. 



7. Use petroleum testing 43° Beaum6 or above at 60° F. 

 Petroleum testing lower than 43° at this temperature is dangerous 

 to the trees. 



In this last statement lies one of the chief dilliculties. Crude 

 petroleum is a very variable substance, and, if it be of too low a 

 degree of the Beaum6 scale, it is likely to injure the trees. 



Fumigation. 

 While fumigation is the most certain method of destroying the 

 scale, its use is not usually practicable by fruit growers in this 

 State. Gas-tight tents, large enough to completely cover the 

 trees, are necessary, and are expensive. The gas generated is 

 a very dangerous one, and its use can hardly be recommended 

 to one not familiar with it. It should be used for the treatment 



