to the hot sun and winds, these wither and dry, thus no longer supply- 

 ing the necessary sustenance, at this time so imperative to the life of 

 the larvae, and they perish. Thus an invasion of a new field from an old 

 one may be prevented. But if the fallowing be delayed, even for a few 

 weeks, the larva? will then have for the most part passed into the pupal 

 stage, during which no food is inquired, and plowing can have little 

 or no effect upon them. This measure, together with the practice of 

 allowing clover fields to stand only two years, would soon reduce the 

 pest to subjugation in any community. No trouble seems to occur in 

 pastures. Once brought under control, it would seem that a system of 

 rotation that involves mowing for hay and seed the first year, pasturing 

 and then breaking up the ground the following year, if generally fol- 

 lowed in a community, would suffice to keep the pest in subjection. 

 Extermination is not possible. 



Approved : 



James Wilson, 



Secretary of Agriculture. 



Washington, D. C, December 28, 1905. 



O 



