EXPERIMENT STATION BULLETINS. 645 



TECHNICAL BULLETIN NO. 56 



FOREWORD 



In June 1920, Mr. J. E. Kotila received the degree of Master of 

 Science from the Michigan Agricultural College. 



Mr, Kotila selected as a minor a study of the life histoi'y of the leaf- 

 li<)i)per of potato, and the results of this study, together with the results 

 of his subsequent work as a research worker in the Michigan Agricul- 

 tural Experiment Station, are embodied in the present paper. The 

 evidence gathered during this investigation seems to be of sufficient im- 

 portance to warrant its publication in this form. 



Respectfully submitted, 



R. H. PETTIT, 



Professor of Entomology. 



