Mr. B. R. Coad, of the Bureau of Entomology, on Hibiscus 

 syriacus, and actually experimentally reared on this plant by 

 him, and partly also on other plants. Thus "by alternating 

 food plants "Experimentally ^ which is less favorable than 

 would be the case under field conditions)," it was found that 

 the weevils have a wide range of hitherto unsuspected adapti- 

 bility" (U. S. Dep. A. Bull. No. 231, p. 3). 



I had shown from this for four years past that with a cot- 

 tonfield totally infested by the bollweevil in the early fall, de- 

 struction of all of the plants, and, in fact, the mere absence 

 of squares suitable for oviposition would force the weevil to 

 accustom itself to breed in plants other than cotton, which of 

 course would in time render the Bureau's old standby of con- 

 trol early destruction of stalks entirely inefficient, and make 

 control of the weevil all the more difficult, and that therefore 

 the only sound principle of control rests in concentrating 

 the weevil upon its original and preferred foodplant, and 

 attacking it there by having poultry pick on the fallen 

 squares and secure adults as described in detail in my Circular 

 No. 152, pp. 1 to 16. 



In the case of the sorghum midge the abundant supply of 

 Johnson grass always present in the past simply thus far has 

 not forced the midge to oviposit on any grass of second 

 choice to any great extent. "J onnson grass being the first to 

 head and bloom gives the midge a good start and by the time 

 sorghum is headed there is a large brood of midges from the 

 grass to infest it" (p. 55). Exactly if you let them mature on 

 it. But my plan provides for a large patch of Johnson grass 



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