162 TREE WOUNDS AND DISEASES 



to the trunk and branches, and give to the 

 trees the appearance of being covered with 

 cotton-wool. It spreads with terrible rapidity, 

 and by exhausting the trees of their sap renders 

 them particularly liable to canker and other 

 fungoid attacks. Fortunately, the ravages of 

 the woolly aphis are readily counteracted by 

 an application of Abol insecticide. In the 

 case of old trees, scrubbing with a brush and 

 soft soap or weak paraffin emulsion during 

 summer has been found a cheap and quick 

 way of getting rid of the pest. As the 

 insect, both in the egg and adult state, is 

 found wintering at the base of the tree stems, 

 an application of carbon disulphide to the 

 soil will be found effectual in destroying 

 the pest. 



The codling moth (Carpocapsa pomonella] 

 attacks the fruit of the apple, and sometimes 

 appears in such numbers in certain districts 

 that the crop is literally spoiled by its depre- 

 dations. The caterpillar, or maggot, as it is 

 more frequently called, deposits her eggs on 

 the fruit as soon as it is formed. Soon the 

 larva appears and, entering the fruit at one 



