No. 4.] ORCHARD SCALES. 361 



with the scale, burning is also the best treatment, as it will 

 be almost impossible to clear such a tree sufficiently to make 

 it valuable for its product, while it would be a constant 

 menace to all other trees around. The sooner a badly in- 

 fested tree is destroyed the better. 



Kerosene. 



During the winter months, while the trees are not grow- 

 ing, much stronger materials can be used for treatment than 

 during the growing season. This is particularly the case 

 between the first of January and the time when the buds 

 begin to swell. During this period pure kerosene may be 

 used under certain conditions with success. Kerosene will 

 kill every scale which it touches, but, unless used in experi- 

 enced 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 gen- 

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

 the following suggestions should be closelv followed : — 



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



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

 obtained. 



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 Xew Jersey, where 

 it was first tried in 1898. While perhaps not beyond the 

 experimental stage as yet, it seems to promise well if pre- 

 cautions 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 



