VI PREFACE. 



of treatment not merely on the scale of experiment, but of 

 results of aijplications to the broad areas of Turnip land reported 

 along the infested country. 



It may most truly be said of this attack that it involves un- 

 usual amount of meteorological and botanical considerations, as 

 well as those customarily found in the attacks of crop insect pests. 

 Therefore for those who care to study the points in detail, the 

 reports with which I have been favoured are laid before them ; 

 but for other readers the " General Summary " appended gives, 

 so far as I am able, a condensed view of the main points. 



ELEANOE A. OEMEEOD, 



Honorary Consulting Entomologist of the Royal Agricultural 

 Society of England. 



ToERINGTON HoUSK, St. AlBANS, 



FchriKinj, 1892. 



