MAN'S CONQUEST OF NATURE 



583 



petitors. The most successful and most numerous of all animals, 

 estimated to do from $1,000,000,000 to $2,000,000,000 annual damage 

 to our crops as well as unestimated harm to man's health and comfort, 

 they are indeed to be reckoned with. Insects are of especial impor- 

 tance to man because of their relation to his food supplies. Plagues 

 of locusts have scourged many lands since earliest history, but with 

 increased cultivation and the introduction of new crops, most insect 

 pests have miore recently turned from their original diet of weeds 

 or grasses to feed upon the introduced food-plants. The chinch 

 bug originally inhabiting the Great Plains regions and living on 

 wild prairie grasses, with the coming of the settler and the raising 

 of cereal crops changed its food supply and became a pest to the 

 farmer. The potato "bug," a beetle that a few generations ago 

 was an inconspicuous and not extremely numerous insect living on 

 wild native plants of the family Solanaceae to which the potato be- 

 longs, upon the introduction of the potato to Colorado promptly 

 changed from its original 

 diet to the new food and 

 spread to new areas where 

 the potato was cultivated. 

 Within a few years it had 

 reached all parts of the 

 United States and re- 

 cently has appeared in 

 England. These are only 

 a few examples of many 

 similar cases that illus- 

 trate the fact that man, 

 in spite of all he can do, 

 is spreading and aiding 

 insect pests which are 

 getting a large portion of 

 his basic food supplies. 



But native forms of in- 

 sect pests are not enough. 

 With the expansion of 

 commerce and the intro- 



introcCir ced 

 in Ke*v Jersey 



^^ran^e 1916-1927 

 range 1927-1930 



The present range of the Japanese beetle. An 

 imported pest. What steps would you advocate 

 to stop its rapid spread :' 



duction of airplanes as well as railways and steamships, man is con- 

 tinually called upon to battle new importations of destructive insects, 

 which in spite of strict quarantine laws are gaining a foothold on our 

 H. w. H. — 38 



