No. 4.] ORCHARD SCALES. 363 



Summary of Treatment. 



1. Fumigation is the most effectual treatment known, but 

 must be given under such conditions as to make it usually 

 impracticable for general use by inexperienced persons. 



2. Kerosene will kill the scale, and is likely to kill the 

 trees as well. A strength of kerosene and water mixture 

 which will not injure one kind of tree may kill another kind. 



3. Crude petroleum may prove the best remedy to use, 

 but must test above 43° Beaume, and be used only in Jan- 

 uary, February or March. 



4. The treatment recommended for general use, except in 

 nurseries, is as follows : — 



(a) Spray infested trees with whale-oil soap, two pounds 

 to a gallon of water, before the buds start in the spring, or 

 at the rate of one pound to a gallon of water, after the leaves 

 are off in the fall. 



(b) Cut back and prune infested trees before spraying, 

 burning the prunings. 



(c) Cover as much of the trunk and limbs with white- 

 wash, about the first of June, as the tree will safely stand. 



(d) Badly infested trees can probably never be entirely 

 cleared, and, if left, will distribute the scale to all trees near 

 by. Cut and burn all badly infested trees. 



(e) In spraying for the scale, remember that, to be de- 

 stroyed, each scale must be touched. Use a very fine 

 nozzle, and try to reach every part of the tree, but stop 

 spraying any part before it begins to drip. 



5. Never purchase stock not accompanied by a certificate 

 of inspection, signed by an authorized inspector, or by a 

 guarantee that it has been fumigated with hydrocyanic acid 

 gas. One who neglects this has only himself to blame if 

 his trees prove later to have been infested. 



