HOW HARM DONE BY INSECTS IS CONTROLLED 365 



man's personal foes. Besides being unpleasant, they are believed 

 to be disease carriers, and as such they should be exterminated.-^ 



How the Harm done by Insects is controlled. — The combating 

 of insects is directed by several bodies of men, all of which have 

 the same end in view. These are the Bureau of Entomology of 

 the United States Department of Agriculture, the various state 

 experiment stations, and medical and civic organizations. 



The Bureau of Entomology works in harmony with the other 

 divisions of the Department of Agriculture, giving the time of its 

 experts to the problems of controlling insects which, for good or 

 ill, influence man's welfare in this country. The destruction of 

 the malarial mosquito and the control of the typhoid fly; the 

 destruction of harmful insects by the introduction of their natural 

 enemies, plant or animal ; the perfecting of the honeybee ; and the 

 introduction of new species of insects to pollinate flowers not native 

 to this country (see Blastophaga, page 38), are some of the problems 

 to which these men have devoted their time. 



All the states and territories have, since 1888, established state 

 experiment stations, which work in cooperation with the govern- 

 ment in the war upon injurious insects. These stations are often 

 connected with colleges, so that young men who are interested in 

 this kind of natural science may have opportunity to learn and to 

 help. 



The good done by these means directly and indirectly is very 

 great. Bulletins are published by the various state stations and 

 by the Department of Agriculture, most of which may be ob- 

 tained free. The most useful of these from the high school stand- 

 point are the Farmers^ Bulletins, issued by the Department of 

 Agriculture. 



Rats as Pests. — David E. Lantz of the Bureau of Biological 

 Survey is authority for the statement that the rat is the most 

 destructive mammal in the world. He estimates the actual money 

 loss from destruction of property by rats each year in this country 

 to be over $200,000,000. Rats destroy the timber in houses, they 

 cause fires by gnawing matches, they destroy great quantities of 

 standing grain and stored food, they kill myriads of young chickens 



^ Directions for the treatment of these pests mp,y be found in pamphlets issued 

 by the United States Department of Agriculture. 



