170 



TREES IN" WINTER 



bark with the spray. Most of the insects, and especially the San 

 Jose species, multiply very rapidly, there being several broods in 

 a season. The fruit trees, like the Apple, Pear, Plum, Peach, 

 Hawthorn, and Mountain Ash are especially susceptible to the 

 attack of scale insects. Young trees should be closely watched, 

 for they are often killed or severely injured before the pest is 

 observed. 



BORERS. 



On account of their habit of feeding about the cambium, 

 layer, the insects belonging to this class are very destructive and 

 are very difficult to control. There are many different kinds of 



Fig. 93. The work of the Maple Borer. 



