FOOD SUPPLY 



41 



It does not take into consideration the present greatly ad- 

 vanced prices which are, no doubt, temporary exacerbations 



FIG. 18. Diagram illustrating the comparative abundance of various types of food-habits in 

 insects. The figures at the left indicate the percentage of species exhibiting the several types. 

 This chart is based on the recorded fauna of a limited area (New Jersey) which includes about 

 10,000 species. (Modified from Weiss.) 



destined to subside, like many of the invasions of insects 

 detailed in one of the following chapters. 



When we consider that insects are, with the exception of 

 the Protozoa and certain marine invertebrates, the most 

 abundant animals on the earth, it is not surprising that no 

 plants appear to be free from insect enemies. I have usually 

 assumed that about one-half of the 450,000 described, living 



