60 Bird Day Book 



pair of gypsy moths would defoliate the United States in eight 

 years. 



These estimates I quote from Prof. Forbush, who in turn 

 gathered them from the United States Biological Survey, and we 

 may say that these cases are fair examples of the reproductive 

 powers of the insectile world. Locusts, army worm, and chinch 

 bugs, unless checked in procreation, soon become countless hordes,, 

 devastating wide areas of the earth's surface. 



It is to be remembered that insects live to eat. Some of them 

 increase their size at birth 10,000 times in 30 days. Dr. Iintner, 

 of the New Jersey Board of Agriculture, reports 176 species of 

 insects attacking the apple tree. (U. S. Biological Survey.) About 

 the same number attack the peach, plum, and cherry trees. Dr. 

 Packard finds 400 species feeding upon the oak ; 300 attack the 

 conifera. The number feeding upon cereals, grains, and garden 

 crops is also very large. 



The reports of the Bureau of Entomology show that destruc- 

 tion by some insects is widely spread and are increasing. Dr. 

 Marlatt estimated that the loss to the wheat-growing States in 1904 

 occasioned by the Hessian fly was about $50,000,000. Dr. Shinar 

 estimates the damage done to crops in the Mississippi Valley caused 

 by the chinch bug in one year as high as $100,000,000. The Rocky 

 Mountain locusts, in years of their greatest activity, caused the 

 States of the Northwest more than $150,000,000. Dr. Lintner 

 estimates the annual loss to farmers caused by cut-worms at $100,- 

 000.00. The terrible loss of $800,000,000 a 'year is fairly easy of 

 proof. 



That the worm does not eat everything that grows is due to 

 several causes — weather, parasites, fungi, insect diseases, insecti- 

 vorous birds, and mechanically applied poisons, which are expen- 

 sive, unnatural, and dangerous. However large may be the share 

 of parasites, fungi, and weather in checking the increase of de- 

 structive insects, investigation shows that it is lamentably insuf- 

 ficient, and the briefs of the bird defenders pretty clearly indicate 

 that the birds have been, are, and will be without question one of 

 the most important agencies in staying the inroads of insect devasta- 

 tion. Men who have had this subject at heart and in hand for 

 many years assert that bird life is one of the most indispensable 

 balancing forces of nature. 



(From Report of the Senate Committee, recommending the passage of 

 tbe McLean Bill which provides national protection of migratory birds.) 



