Reasons For Pest Increase

When there is an abundance of food and

conditions are otherwise favorable, any animal or plant will thrive

better than when the food supply is scarce and conditions unfavorable.

As long as apple trees were scattered and few in number there was not

the opportunity for the development of apple pests, but as soon as

they became numerous the prosperity of bugs and minute plant parasites

was wonderful to see. Another factor which has been at least partly

responsible for the great increase in our insect life is that man has

upset nature's balance by destroying so many birds, and, by

interfering with their natural surroundings, driven them away. Birds

are great destroyers of insects, and their presence in the orchard

should be encouraged in every possible way. Add to these facts the

marvelous fecundity of the insect tribe, and the increase is less

remarkable. Loss from these orchard pests has now run up into the

millions. It has been estimated that the loss in the United States

from wormy apples alone is over $11,000,000 annually. Thus has the

necessity for fighting these enemies of good fruit arisen.



In order successfully to combat an insect or a disease it is very

necessary to have a somewhat detailed knowledge of its life history

and to know its most vulnerable point of attack. It is impossible to

work most intelligently and effectively without this knowledge, which

should include the several stages of the insect or disease, the point

of attack, the time of making it, and when and with what it can be

most easily destroyed. The number of insects and diseases which affect

the apple is so great that it is simply out of the question to treat

them all in detail here. We have therefore selected nine insects and

three diseases as those pests of the apple which are most common and

whose effects are usually most serious. The essential facts in their

life histories and their vulnerable points will now be pointed out.

The method of study may be taken as applicable to any other pests

which it may be necessary to combat.