PLUMS AND CHERRIES 183 



son that the careful grower sprays his orchard 

 every year, regardless of whether he has a crop 

 of fruit or not. The leaf must always be con- 

 sidered the gauge of the health of the tree, 

 regardless of what sort of tree it may be, and in 

 the leaf is reflected, too, not only the crop 

 which may be on the tree at the time but the 

 crop of the next year, for the fruit buds are 

 formed and must be nourished almost a year in 

 advance of their blooming period. 



Scale insects attack plum and cherry trees 

 just as they do other fruits. The sour cherry, 

 however, is considered rather immune to the 

 much talked of San Jose scale, but it has a 

 special scale of its own (the cherry scale) that 

 sometimes becomes troublesome. Jap plums 

 are frequently attacked by San Jose scale with 

 all the enthusiasm which that pest exhibits for 

 the peach — another similarity between the two 

 fruits. 



The fruit tree bark beetle, a tiny beast that 

 bores knitting-needle-sized holes in the trunk 

 and branches, is a common pest on all fruit 

 trees but especially on cherries. It is, however, 

 almost always a secondary parasite for it does 

 not relish the juices to be found in a vigorous 

 tree. It will nearly always be found in trees 

 which have been injured through some other 

 cause and is not to be feared by the grower who 

 keeps his trees in a state of healthy activity. 



