CHAPTER III 



THE IXSECT PROBLEM 



Work of insects in nature. Geologically the present is 

 known as the age of man, but zoologically it is the age of 

 insects. There is but one species of man, — Homo sapiens, — 

 while over 300,000 species of insects have been described, and 

 it is estimated that in all there are not fewer than 10,000,000 

 species in the world. The number of individuals of any one 

 species may cover the forests and fields or even darken the 

 skies over large areas. 



Compared with other animals insects are small, having 

 developed, instead of size, refinement of mechanism and organ- 

 ization and great reproductive power. This latter often sur- 

 passes belief, but since it shows us the importance of natural 

 checks to the increase of insects, it must form one of the 

 central features of our insect lessons. A pair of San Jose 

 scales could produce progeny in a season to the number of 

 3,216,080,400. A single female plant louse might give origin 

 to 9,500,000,000,000 in a season (Forbes). The house flies of 

 a city, if all tlie young survived and could find food, would 

 bury it before the people could escape (Jordan). We are led 

 from these facts to see the importance of insectivorous animals ; 

 for example, it has been estimated that the birds of Nebraska 

 consume dailv 86,000 bushels of insects durino- the warm 

 months (B runner). 



No insects are used for food by civilized man, and it is 

 remarkable that in so great a number of species so few^ pro- 

 duce anything of value to man. Silk, honey and beeswax, 

 shellac and cochineal, and cantharides virtually complete the 



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