of 



ORONO 



BULLETIN 253 



JULY, 1916 



SYRPHIDAE OF MAINE 



This bulletin contains a general discussion of a group of 

 flies which are, for the most part, not injurious, but beneficial 

 in destroying crop-pests. Their life-stages, habits, structure 

 and economic importance are described, and practical measures 

 for increasing their usefulness are suggested. 



A detailed summary is given on pages 193 to 197. 



