43 



graphing birds we noted that they were bringing army worms 

 to their young, and neither my crops nor my neighbor's, on 

 whose premises these nesting boxes had been put up, suf- 

 fered at all by the army worms. Twenty rods west of my 

 farm some injury was done to the grass by the worms, and 

 from there over and through the town of Wareham, where no 

 attempt had been made to increase the birds, much grass was 

 eaten and some corn. Where birds are sufficiently abundant, 

 they destroy the first generation of the army worm, and so 

 prevent excessive increase. Usually, when the first brood is 

 unchecked, it is the second generation of the year that becomes 

 numerous enough to devastate the crops. 1 



In 1894 my assistant, Mr. Charles E. Bailey, experimented 

 in an old orchard on my ground at Medford, Massachusetts, to 

 determine whether any effect on orchard pests could be pro- 

 duced by attracting birds. The trees were not sprayed nor 

 protected from insects in any way, but food was provided for 

 birds in winter, nesting boxes were erected in spring, and an 

 attempt was made to protect birds from their enemies. By 

 these means the number of birds feeding about the place was 

 much increased. It happened that orchard insects were very 

 plentiful and destructive that year, but the birds in our orchard 

 destroyed many thousands of eggs and females of the fall and 

 spring cankerworm moths, eggs of the tent moth, caterpillars 



of the gypsy moth, case- 

 bearers, tineids, etc. By 

 examining the contents of 

 the stomachs of chicka- 

 dees, Mr. Bailey reached 

 the conclusion that a 

 single chickadee in twenty- 

 five days would destroy 

 138,750 eggs of the can- 



Chkar yer f rchard kerworm moth. The sig- 



nificant outcome of our 



experiment was, that while all the other orchards in the neigh- 

 borhood except the one nearest ours were stripped of their 



i Seventh Annual Report of the State Ornithologist, Massachusetts State Board of Agriculture, 

 1914, pp. 20-22. 



