ENTOMOLOGY 



WITH SPECIAL REFERENCE TO 



ITS ECOLOGICAL ASPECTS 



BY 



JUSTUS WATSON FOLSOM, Sc.D. (HARVARD) 



ASSISTANT PROFESSOR OF ENTOMOLOGY AT THE UNIVERSITY OF ILLINOIS 



THIRD REVISED EDITION 

 WITH FIVE PLATES AND 308 TEXT-FIGURES 



PHILADELPHIA 



P. BLAKISTON'S SON & CO. 



1012 WALNUT STREET 



