98 THE CONNECTICUT POMOLOGICAL SOCIETY. 



water on such trees we should be hable to injure the tree seri- 

 ously. If it is applied to dormant trees in proper weather, 

 which means a bright day, and there is not too much put on, 

 it will not injure the tree. At least that is what our experiments 

 show and we have reason to believe that this is correct. Crude 

 oil may also be used undiluted but we must be sure to use only 

 certain grades of oil. It was found that oil by the Beaume 

 hydrometer test showing a specific gravity below 43 degrees 

 would not do. Anything above 43 degrees is safe to use, but 

 the higher we go the more expensive the oil becomes, and 

 anything below that is apt to injure the trees. 



There are also other efifective methods of treatment, one of 

 which is fumigating with hydrocyanic acid gas. This has 

 been used in California and also in Maryland and some of the 

 other states, but so far, in Connecticut, we have not done much 

 of anything with it in orchards, largely on account of the 

 expense. Nursery stock is now being fumigated in Connecti- 

 cut quite extensively. 



We can use kerosene and water, using 10 per cent, of the 

 oil upon the trees and foliage in the summer time. We found 

 that 15 per cent, of kerosene could be applied to peach trees 

 when in foliage. With that proportion we found we had a few 

 leaves fall, and here and there a peach would be destroyed but 

 there was no great injury to the tree, and we feel now that the 

 trees can be sprayed at that time with the preparation contain- 

 ing 15 per cent, of kerosene. I should not want to go above 

 that. It is doubtful if a 10 per cent, mixture will kill all the 

 scales, but it kills many of the young ones. We found it may 

 make a difference when we apply it. In two experiments where 

 the trees w^ere sprayed, one, I think, the 19th of June, and the 

 other the 26th, we only killed about half the scale insects on the 

 trees. In another instance where the spraying was done on the 

 24th of July less than one per cent, of living insects remained. 

 It may be that at the time the adult scales are ready to give 

 birth to the young, they may be harder to kill than at other 

 times. 



It is quite important that the oil and water should be well 

 mixed. There is quite a variety of apparatus on the market 

 for that purpose. Some of the apparatus which appears in 

 some of the pictures I have shown does the work very well. 



