THE INSECTS— ARTHROPODS 



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serious germ diseases of man are spread by insects. Our clothing is 

 destroyed by insects; furs, woolens, mohair, and feathers furnish good 

 eating for the larvae of the clothes moth. Some do not wait for material 

 to be made into clothing before destroying it ; the cotton boll weevil may 

 take as much as a fourth of the entire potential cotton crop each year. 

 Books and valuable papers are injured and destroyed by the silverfish, 



Photo by Winchester 

 Fig. 15.1. The corn ear "worm" does great damage to the corn crop by eating the 

 kernels. It is the larval form of a moth, Hcliothis armigera. 



or fishmoth ; termites destroy all types of wooden construction and may 

 enter and destroy books and other stored paper products. 



When we constantly have to battle insects to hold such destruction in 

 check and spend millions of dollars each year in attempts to control them, 

 we may wish that there were no such things as insects on the earth. Yet, 

 insects are of such great economic value that if they were completely 

 eradicated we would find this a very different world in which to live. 

 Most of our fruits, many vegetables, and many of our grains would dis- 

 appear with them. There would be no cotton or silk; most of the land 

 birds and most of the fresh-water fishes would die of starvation. Many 



