84 



of 1917, it was apparent that growth had been retarded and that sub- 

 sequent attacks would mar their beauty permanently. An extreme case 

 of injury by mites is clearly indicated in the accompanying photographs 

 (Figures 1, 2, and 3), of a tree and branches which have been infested 

 for a period of at least three years. 



The remedies which Professor Slingerland found effective for mites 

 that attack other plants may prove effective on the maple. He has 

 found that they can be exterminated by spraying trees in winter with 

 kerosene emulsion diluted with five to seven parts of water. This will 

 penetrate buds and kill the mites which hibernate there. 



