INTRODUCTION 



ENTOMOLOGY is briefly defined as the study of insects 

 in all their relations and activities. Its importance is due 

 to the numbers of species and the abundance of individ- 

 uals in the insect group. In both these respects insects 

 form by far the greater portion of our land fauna. Vari- 

 ous estimates place the number of species of insects at 

 from one to ten millions and the number of individuals 

 is far beyond calculation. Of these species nearly a half 

 million have been named and described. 



The range of insects is almost universal on land, but 

 only a few forms are marine in habitat. Intensively speak- 

 ing, their range is equally great. In any given locality 

 insects may be found inhabiting every conceivable situ- 

 ation and living on the greatest variety of foods. 



When we consider the vast numbers of insect forms 

 and their wide distribution and range in food habits it 

 seems inevitable that many of these forms should clash 

 with man, and this is indeed the case. Many of the 

 earth's products which are most useful and highly desira- 

 ble to man are attractive to insects as well. Man, in his 

 assumed character of the dominant animal, claims prior 

 right and such insects as affect his welfare or comfort are 

 listed as pests. 



Less account is taken by man of his insect allies, those 

 forms which minister directly to his needs, or those which, 

 in a roundabout way, add to his pleasure or his revenues. 



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