56 JOURNAL OF ECONOMIC ENTOMOLOGY [Vol. 3 



carbon di-sulfid as a grain fumigant, we know of nothing equally- 

 effective which may be used any more satisfactorily. At the most, the 

 expense of treatment will average less than a cent per bushel, and this 

 is a very small cost to greatly lessen, if not entirely prevent, insect 

 injury and the loss of from 25 to at least 65 per cent of the real value 

 of corn, which must be stored for a period of several months in the 

 Southern States. 



Mr. Headlee: I have taken great pleasure in listening to this 

 paper, for it seems to me that Doctor Hinds has hit upon the proper 

 method of investigating the effect of gases on this insect. He has taken 

 into consideration the difference in temperature and has probably 

 considered the effect of moisture. It seems to me that we are coming to 

 a time when the measures for the control of injurious insects must not 

 only be based on a fundamental knowledge of their life economy in 

 relation to the environment in which they live, but the relation of the 

 measures themselves to the environmental conditions under which they 

 will be applied must be fundamentally investigated. 



The work of which we have just heard is a long step in this direc- 

 tion. The fundamental investigation of the life economy and meas- 

 ures of controlling seriously injurious insects in relation to environ- 

 mental conditions is one of the most promising lines open to the 

 economic entomologist. 



I noted a few points which I would like to ask about. Is the rice 

 weevil the largest destroyer of corn in the South? I raise that point 

 for the reason that in south Kansas the Angumois grain moth seems 

 to do the most damage to stored corn. Doctor Hinds did not report 

 on the effect of moisture, and I would like to know whether in his 

 opinion it had any important part in his results. 



Mr. R. I. Smith: There is one thing, I think, Professor Hinds 

 would have explained, if he had taken time.. He said that in one ex- 

 periment he found nearly 7 per cent of the weevil stages alive, and 

 that the same grain, after receiving a second treatment in October, a 

 month or six weeks later, with a greater strength, showed 38 per cent 

 of the weevil stages alive. Of course, that seems very contradictory 

 and inexplicable, but as I made some tests along this line last year I 

 would say that the weevils which remained alive after the first treat- 

 ment in September would account for the increase. They certainly 

 do multiply rapidly. 



I would like to ask in what way he determined the percentage of 

 live weevils which has been shown in the results. 



]\Ir. Hinds : In most cases a period of at least a week elapsed be- 



