xvi INTRODUCTION 



cieties are doing a great deal to better and 

 beautify our towns ; but in their attempts to pre- 

 serve the trees against the plagues of insects that 

 in late years have descended upon them, they 

 sometimes seem to be baffled by the magnitude of 

 their task. Their best allies in this work have 

 hardly been recognized, and it is most important 

 to understand the nature and extent of the help 

 that may be obtained. The relation of birds to 

 insects is only just becoming known. 



It is said that two hundred millions of dollars 

 that should go to the farmer, the gardener, and the 

 fruit-grower in the United States are lost every 

 year by the ravages of insects that is to say, 

 one tenth of our agricultural products is actually 

 destroyed by them. The ravages of the gypsy 

 moth in sections of three counties in Massachu- 

 setts for several years cost the State, annually, 

 $100,000. Now, as rain is the natural check to 

 drought, so birds are the natural check to insects, 

 for what are pests to the farmer are necessities of 

 life to the bird. It is calculated that an average 

 insectivorous bird destroys 100,000 insects in a 

 year ; and when it is remembered that there are 

 over 100,000 kinds of insects in the United 

 States, the majority of which are injurious, and 

 that in some cases a single individual in a year 

 may become the progenitor of several billion 

 descendants, it is seen how much good birds do 

 ordinarily by simple prevention. 



