AGRICULTURAL USES OF BIRDS. 



943 



insects become a pest; and they will cease to trouble him only in proportion as he shall 

 restore the balance of which Nature shows the necessity. It is not that insects are to be 



destroyed or condemned as a class. Noth 

 ing is created except for the fulfillment of 

 some good end; and the value of insects is 

 not inferior to that of any other class of an 

 imal life; none are without their legitimate 

 uses; and it is only when they are stim 

 ulated to excessive increase that they be 

 come troublesome. Before passing judg 

 ment upon them, we must remember that 

 insects are, in a great many ways, very use 

 ful and valuable to man. They prepare for 

 us the material for silk, which, in its manu 

 facture, furnishes profitable employment to 

 multitudes of men, women, and children, 

 and brings in large revenues to the country. 

 Insects we must thank for honey, the 

 sweetest of sweets. The air we breathe 

 and the water we drink are kept pure and 

 wholesome by the agency of myriads of 

 little creatures which draw sustenance 

 from the impurities of the elements. It is 

 not, then, that insects are to be extermina 

 ted, even if it were possible, but only kept 

 in check. 



The majority of our native birds have 

 but one brood of young in the course of the 

 year; a few have two or three. In the case 

 of the smaller insect-eating birds, the num 

 ber of eggs to a brood is, on an average, not 

 more than five. Some of the larger birds, 

 as the various GallinaB, lay from five or six 

 to twenty eggs to a brood. On the other 

 hand, the reproductive energy of insects 

 is truly marvelous. It is said that a single 

 pair of grain weevils have produced six 

 thousand young between April and Au 

 gust. The common varieties of aphides or 

 plant lice, which are found on almost all 

 kinds of plants, are produced in spring 



Upper fig., WOOD PEEWEE (Confopus virens); lower, KING BIRD f rOTri .. i fl ; ( i t v, p o pa &amp;lt;?rm hpfnrp- and 

 (T. carottnensis). Insessores. re &amp;gt; anu 



through the summer only females are 



developed. At the last of the season, males and females both appear; and eggs are laid 

 for the brood which hatches early in the spring. Reaumer 

 says that one individual in one season may become the pro 

 genitor of 0,000,000,000. The silk-worm moth produces 

 about 500 eggs, the great goat-moth about 1,000, the tiger- 

 moth 1,GOO, the female wasp at least 30,000. There is a spe 

 cies of white ants, one of which deposits not less than sixty 

 eggs a minute, giving 3,600 in an hour. How, then, shall 

 this enormous mass of insects be kept in check? What shall 

 prevent them from overrunning the country, destroying 

 crops and devastating the land? 



Food of Birds. Various causes operate to check 

 the undue increase of insects, and the chief of these is the 

 appetite and instinct which a wise Providence has given to 



birds. If the number of eggs produced by insects is won- R EDST ABT (Setophaga rutidiia). 

 derful, the number destroyed by a single bird is no less so. 

 Audubon says a woodcock will eat its own weight of insects in a single night. Dr. Bradley says 



