FOOD OF WEST VIBCIXIA BIROS 19 



given as suggestive of what might be our condition if birds should 

 cease to hold in check the many kinds of insects. More than three hun- 

 dred thousand kinds of insects have been described and every year 

 many new species are being discovered by entomologists. No one has 

 yet ventured to make a catalogue of the different kinds of insects to be 

 found in West Virginia since the list would be so long as to make 

 such an undertaking practically impossible. It is probably no exag- 

 geration at all to say that our Wfest Virginia list of species of insects 

 numbers from five to ten thousand. And not only are there numerous 

 species, but individuals of some species are so abundant as to be beyond 

 all reckoning. One famous entomologist tells us that he saw at a single 

 glance more individuals of a certain species of snow flea than there 

 are human beings on the entire face of the earth. Another tells of esti- 

 mating the number of plant lice on a single cherry tree and finding that 

 they numbered twelve millions. Sometimes army worms, chinch bugs, 

 Rocky Mountain locusts, certain species of beetles and other forms of 

 insect life come in innumerable millions. When one considers the 

 enormous reproductive capacity of insects, their present numbers and 

 the possibilities of unchecked increase in the future one shudders at 

 the thought and dreads the day when the crawling, creeping, buzzing 

 destructive creatures may be far worse than they are now. Prof. Riley 

 tells us that the twelfth brood of the hop vine aphis, coming in one 

 season from a single pair, would number, if left unchecked by natural 

 enemies, not less than 10,000,000,000,000,000,000,000, a number that is 

 almost infinitely beyond our powers of comprehension. Most of our 

 insects increase very rapidly, and, if left unchecked by natural enemies, 

 would soon lay waste and bare the entire surface of the earth. These 

 billions of insects, it must be remembered, eat most voraciously. They 

 require far more food than most forms of animal life. Dr. Forbush 

 says, "Many caterpillars daily eat twice their weight in leaves; which 

 is as if an ox were to devour, every twenty-four hours, three-quarters 

 of a ton of grass." Insects develop very rapidly, in most cases, and 

 require much food to keep up this ceaseless growth. In view of the 

 uncounted numbers of species, the billions of individuals of some of 

 these species, their rapid rate of increase and the vast amount of food 

 required by them, it becomes very evident that all ordinary and extra- 

 ordinary, all natural and all artificial, means of restricting the increase 

 of harmful species of insects .is absolutely imperative. Of all known 

 methods of curbing the geo/tnetrical progression of increase among the 

 insects, none is better than nature's own effective way of sending 

 birds to eat them up. Some birds scratch among the leaves and find 

 the insects that are working on the ground or that infest the leaves 

 and debris; others feed on insects that are found in pasture lands amon? 

 the grasses, and lower forms of plant life; some search continuously 

 among the shrubs and lesser trees; others climb over the trunks and 

 branches with vigilant eyes; and still others catch the insects that fly 

 about in the air. Some birds take the dormant insects that live over 

 winter and thus prevent the possible increase during the coming season; 

 others eat eggs and the very smallest insect forms; while still others 



