No. 4.] THE GYPSY MOTH. 223 



and the vastly greater familiarity with all phases of the life 

 history of these species by all classes of the people, partly 

 resulting from the older civilization, partly from educational 

 methods and partly from the abundance of elementary and 

 popular literature on questions of this character, the denser 

 population and the resulting vastly smaller holdings in farms, 

 the necessarily greatly diversified crops, the frequent rotation 

 of crops, together with the clean and close cultivation neces- 

 sitated by the small size of the holdings and the cheaper and 

 more abundant labor, have all resulted in a very different state 

 of affairs regarding the damage which may be done by injuri- 

 ous insects than that existing in this country. When out- 

 breaks of special insects occur in Europe they are handled by 

 commissions." European nations, therefore, can afford to let 

 the insect problem alone to a greater extent than the United 

 States, for the reason that it is of infinitely less importance 

 with them than with us.* 



In France and in some of the German states outbreaks of 

 forest insects are fought by the government forest authorities. 

 In the United States the conditions are quite different. Man 

 is continually disturbing the balance of nature by clearing 

 away the forests, by planting trees upon the prairie, by intro- 

 ducing plants from foreign countries and by destroying animals 

 and birds which feed upon his insect foes. Farms here are 

 large as a rule as compared with those of central Europe, and 

 there is much land unfilled and unoccupied where injurious 

 insects can breed unhindered. There are large areas devoted 

 to special crops, which offer the most favorable conditions for 

 the multiplication of insects which feed on those crops. 



While the crops of the agriculturist of the United States 

 suffer from the great hordes of indigenous insects, the Ameri- 

 can farmer also has to battle with many injurious introduced 

 species. 



The Losses caused by Insects in the United States. 



Probably no country has suffered so much in the same length 

 of time from the ravages of insects as the United States. The 

 Hessian fly (Cecidomyui destructor, Say.), imported from 



* " A brief account of the rise and present condition of official economic entomology," 

 L. O. Howard, "Insect Life," Vol. 7, No. 2, page 74. 



