Page:Stebbins, C. A. - A Guide to the Birds of the Pacific Coast.djvu/6

 from the nest, would you not fly and fly until you dropped from exhaustion, for nothing would matter now?

Can you solve the following problems? "Suppose there are 50 apples in a peck; how many might a codling moth spoil if she lay 50 eggs on as many apples, and half of these eggs hatch female moths, and in the second brood again, each lay 50 eggs on as many apples?"

Ans.—26 pecks.

"If a Downy Woodpecker eats only one codling moth larva each day from November to April inclusive, 180 days, what might be the value of its work to an orchard if apples are worth 50 cents a bushel?"

Ans.—$565.

It has been estimated that the damage caused annually in three states alone by the codling moth amounts to nearly $8,000,000. The moth spoils from 25 to 75 per cent of the apple crop of the United States and Canada each year.

Statistics from the United States Department of Agriculture for 1904 show a tax of $1,195,000,000 imposed upon the people of the United States by insects during that year.

"Certain moths deposit hundreds of eggs in a season and were each egg to hatch and each insect to come to maturity and go on producing at the same rate the entire earth in a few years would be carpeted with crawling caterpillars and the moths in flight would cover the earth like a blanket or fog," and in four years the foliage of the United States would be destroyed.

In giving a description of conditions after a volcanic eruption, which occurred in Guatemala, a coffee planted said: "One of our greatest troubles was that of sickness, owing to the balance of nature having been upset by the eruption, which, having killed all the birds for some hundreds of miles, enabled the flies, mosquitoes and rats to multiply to such an extent that life to man became nearly unbearable. The immediate consequence was an epidemic of malaria, which cost more lives than the eruption itself—many times more. It has passed away, happily; the birds having come again, the breeding of these pests is checked, and the district again enjoys the excellent reputation for health that it deservedly had before."

Authorities have observed one pair of grosbeaks feed their young in one day of eleven hours, 800 larvae of insects. Three thousand ants have been found in the stomach of a "flicker" at one time. Five hundred mosquitoes were counted in the stomach of a nighthawk. A pair of nesting wrens took more than 600 insects from a garden in one day. Swallows eat more than 1,000 flies a day. The stomach of a quail held 100 potato beetles. Another had eaten 500 chinch bugs.

Bird authorities of Massachusetts estimate one day's work by the birds in that state to be the destruction of 21,000 bushels of insects. In Nebraska 170 carloads of insects are destroyed each day. While thousands of insects are destroyed through other natural agencies, just think for a moment of the number of insects all the birds in the whole United States might destroy in one day and in one year.