: 



BLAKISTON'S SCIENCE SERIES 



ENTOMOLOGY 



WITH SPECIAL REFERENCE TO 



ITS BIOLOGICAL AND ECONOMIC ASPECTS 



BY 



JUSTUS WATSON FOLSOM, Sc.D. (HARVARD) 



ASSISTANT PROFESSOR OF ENTOMOLOGY AT THE UNIVERSITY OF ILLINOIS 





ScconD IRcviscD JEfcitton 

 TliHitb four plates an5 304 eit=3Ficuircs 



PHILADELPHIA: 



P. BLAKISTON'S SON & CO. 

 1012 WALNUT STREET 



1913 





