118 The Bulletin. 



whatever to the life of au insect — how long it lives, where it lays its eggs, 

 how long it takes to get grown, what changes of form it undergoes, etc. We 

 merely ignore all these details. 



And yet there are many more different kinds of insects than there are of all 

 other animals combined. And in their effect upon human welfare insects are 

 far more important than any other group of animals, with the exception of 

 those which we use for food or as beasts of burden. 



Occasionally some insect makes its appearance in gi-eat numbers on our 

 crop, and then we begin to see the great power for harm that there is in these 

 tiny creatures. Some insect pests have been of such severity or attracted such 

 attention as to figure quite prominently in what we might call agricultural 

 history. The Chinch Bug has at times done enormous destruction to grain 

 crops, while the Hessian Fly has in certain j^ears caused a loss in wheat ruu- 

 ning into millions of dollars. The Potato Beetle caused genuine and deep- 

 seated concern when it spread eastward from the Rocky Mountains and for 

 a time threatened to stop the growing of the Irish potato. The San Jose 

 Scale caused much uneasiness among fruit growers, and many State legisla- 

 tures passed laws looking towards its control. The Browu-tail and Gipsy 

 Moth have caused enormous losses in New England, and other eastern States 

 are taking official steps to guard against the introduction of these pests in 

 their limits. The Cotton Boll-weevil has laid a heavy tax on the cotton grow- 

 ers in Texas, Louisiana, and adjoining States, and bids fair to spread over 

 the entire cotton area. In the forests there have been some notable outbreaks, 

 a good example (though a moderate one) being the damage to short-leaf pine 

 by the Southern Pine Bark-beetle during the present year (1911) in the South- 

 ern States. 



Each individual year witnesses severe injury by insects, and each year cer- 

 tain species are more abundant than usual. Thus one year many kinds of 

 plant lice may be destructive, while the next year they may not attract at- 

 tention, but Chinch Bug may be excessively abundant. And so it goes: a 

 season that is unfavorable to one insect pest may just suit another. 



•Years and years ago, when there were no agricultural colleges, no experi- 

 ment stations, and no State or National Departments of Agriculture, each 

 farmer had to learn to master his own problems. If an insect was destructive, 

 he must find a remedy himself or do without. There was no one to whom 

 he could appeal for information or help. But when we advanced far enough 

 to establish these great institutions for the purpose of aiding agriculture, the 

 farmers began to look to them when special difficulties arose. 



And for a long time entomology was not recognized as important enough 

 to justify the employment of specially trained or skilled men. But as time 

 went on, and one new pest after another made its presence felt, and the call 

 for definite, effective help became more insistent, men were employed to give 

 the whole of their time and talents to the study of insects and remedies for 

 those that are destructive. 



To-day there is scarcely a State that does not have one or more men em- 

 ployed at public expense to conduct studies on the insect pests, and to aid the 

 farmers in protecting crops from their ravages. Most of the States also have 

 laws which are designed to keep new pests from being carried in on shipments 

 of trees or plants ; the National Department of Agriculture at Washington has 

 a force of several hundred men engaged in this work, and all over the coun- 

 try, in every State, there is a definite system of work going on to find out 

 new facts in regard to insect pests, and to teach the farmers how to use what 

 has already been found out. 



The exact life-history of practically every important insect pest is known 

 to more or less degree, although important details or important habits are 

 being discovered every year which makes our methods of control more certain 

 or more simple. 



It is not to be supposed that easy and inexpensive methods are known for 

 controlling all sorts of insect pests. It is true that some are very easily con- 

 trolled if one is but prepared to apply the remedy, as, for example, the Potato 

 Beetle, which is easily controlled by the use of Paris green; others require 

 careful and painstaking hand-labor, like the Borers in fruit trees; and there 



