CHAPTER XI 

 ORCHARD INSECTS 



It is not expected that this chapter will include, by any 

 means, all of the insects with which the orchard o^vner is likely 

 to have dealings. To do that would require a volume in itself. 

 An endeavor has been made to select merely those insects which 

 experience and observation have shown were almost certain to be 

 commercially important to the man who grows an orchard. And 

 they have been treated in the briefest possible way and princi- 

 pally from the standpoint of fighting them in the orchard, only 

 enough of their life history being included to give a key to the 

 most effective line of treatment. 



Following the custom of almost every one who writes on this 

 subject, the writer wishes to lay down certain general principles, 

 a knowledge of which ought to enable the orchardist to select, 

 with a fair degree of certainty, the remedies that should be most 

 successful. Of course the details will vary slightly with each case, 

 but it should be possible for anyone to select the general line of 

 attack. 



The first general rule is that if an insect actually devours the 

 tissues of the plant, so that anyone can see very evidently where 

 it has been at work and that some of the tissue has disappeared, 

 then the cheapest and best remedy is some kind of poison applied 

 to that part of the plant where the insect is feeding. In other 

 words, it is cheaper to poison an insect by means of the food it 

 eats than it is to kill it in any other way ; but you are able to 

 kill it in this way only when it chews off a piece of the leaf or 

 fruit and swallows it. 



Take the tent-caterpillar as an example of this class of in- 

 sects. Almost every one is familiar with its work. The tree 

 attacked looks more and more ragged as its leaves are eaten 

 until finally it may be entirely stripped of foliage. It ought to 

 be evident to anyone that these insects are devouring the plant 

 tissues and can be killed through their food. Some sort of poison 

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