130 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 9 



Mr. F. M. Webster: I do not think anj- fertilizer was used at all. 

 There might be a difference between the low land and the high land 

 in North Carolina. 



Mr. Z. p. IMetcalf: The reason I mentioned the fact that the field 

 in which corn followed cotton was a field of considerable elevation 

 whereas the field in which corn followed corn was much lower, was be- 

 cause all other things being equal corn bill bug injury is much Avorse 

 in low fields than it is in high fields, yet here was a case the exact 

 reverse of this. I do not wish to leave the impression that crop rota- 

 tion is not of some benefit in our fight against the corn bill bug. What 

 I wanted to say was that I can see no reason why the corn bill bug 

 should not spread to fields that had been in cotton the year previous. 

 At least I can see no reason why the corn bill bug should stop in ad- 

 joining fields at the very row where the cotton field commenced, unless 

 there was some other factor, such as time of planting or kind of fertili- 

 zation involved. 



Mr. H. a. Gossard: I would like to ask if anj' of these gentlemen 

 can tell me if there is any evidence that stirring or cultivating the in- 

 fested land has any effect on the insects; by being disturbed they might 

 be excited to flight and leave the field? A few Ohio farmers have writ- 

 ten me that by very industriously cultivating the corn at the time of 

 attack, the attack ceased. 



Mr. Z. p. Metcalf: We have tried thorough cultivation in the 

 same plot with practically no cultivation and while corn does not grow 

 as well where it is not cultivated yet it was impossible to notice any 

 very great difference in the amount of injury between the cultivated 

 plot and the uncultivated plot. 



Mr. William Hayes: I know of a field where the corn was bujned 

 in early spring. I found bugs in the stumps after the fire had passed 

 over them. 



Mr. S. J. Hunter: As I see it, IMr. Hayes has placed the em- 

 phasis on the right point; viz., rotation of crops. 



In the case of the Diabroticas in corn it has been our experience 

 that no serious injury occurs until after corn has been planted in the 

 same ground for thi'ee years or more. 



President Glenn W. Herrick: We will now have the next paper 

 by Mr. Schoene. 



