PREFACE TO THIRD EDITION. 
This bulletin was published in 1895. The demand for it 
soon exhausted the supply. It was reprinted in the succeed- 
ing year, together with other bulletins of that year, but has 
been long out of print. The demand for literature of this 
character has induced the secretary of the Board of Agri- 
culture to ask the ornithologist to prepare another edition, 
which is presented herewith. 
Since this paper was written the common cankerworms 
have decreased in numbers until they are no longer regarded 
as pests of the first magnitude. How much of this decrease 
is attributable to birds the reader may judge. 
