172 TREE WOUNDS AND DISEASES 



kinds of apples and pears are more liable to 

 attack than others. Remedies consist in winter 

 spraying with sulphate of copper, i Ib. to 

 25 gallons of water, or the Bordeaux mixture 

 applied in summer. 



The pear midge (Diplosis pyrivora) and the 

 pear leaf blister (Eriophyes pyn) both commit 

 damage in fruit orchards, the former causing 

 the fruit of the pear to become distorted and 

 fall off prematurely, while the latter causes the 

 leaves to become blistered and quickly change 

 colour from green to a clear brownish red. 

 Burning infested leaves is to be recommended 

 in this case ; while the midge may be kept in 

 bounds by destroying attacked fruit and top- 

 dressing the adjacent ground with kainit or 

 guano. 



Silver leaf (Stereum purpiireum)^ which is 

 readily recognised by the silvery appearance of 

 the leaves, attacks the plum, peach, and other 

 fruit trees. It is a fungus growth that gains 

 admission through injuries to the bark of the 

 attacked trees. Preventive measures can only 

 be recommended, and in the case of a whole 

 tree being affected it should be cut down and 



