CHAPTER XIII. 



INSECTS AND DISEASES. 



INSECTS are among the most formidable enemies to successful fruit" 

 culture. It has been computed that the losses occasioned by the 

 curculio alone amount to at least a million of dollars annually. 

 Planters are deterred, by the attacks of this insect, from attempts to 

 raise the apricot, nectarine, and plum ; and the market supply of 

 apples and pears is much disfigured by it. The apple worm is 

 becoming scarcely less formidable. As a general rule those reme- 

 dies are of little value which attempt merely to repel insects without 

 destroying them at once. The first question, therefore, which may 

 be properly asked when a remedy is proposed is does it kill the 

 insert ? 



DESTRUCTIVE INSECTS. 



The Caterpillar (Clisiocampa Americana). This has been a most 

 serious enemy to the apple, and some other trees, in most parts of 

 the country. It has its seasons of increase and decrease. Some 

 years it has nearly stripped whole orchards ; and again it has 

 diminished in numbers in successive years, till few could be found. 



There are many species which feed on the apple leaf ; but the one 

 here alluded to, is that known as the common orchard caterpillar, 



which is hatched in spring as 

 soon as the leaf-buds begin to 

 ^^ open. At this time, it is not the 

 ^ tenth of an inch long, nor so 

 < ^ large as a cambric needle, but 

 it continues to increase con- 

 stantly in size for several weeks, 



.. . .^.-Moth of Apple-tree Caterpillar. Until tw inches lon g and * 



quarter of an inch in diameter. 



It then spins a cocoon and passes to the pupa state. In the latter 

 part of summer it comes out a yellowish brown miller (Fig. 177), lays 

 its eggs, and dies. The eggs are deposited in cylinders or rings, 



