CARBON DISULPHID AS AN INSECTICIDE. 21 



the same conditions the cowpea weevil ^ will live for about 35 minutes, 

 the rice weevil - for about 60 minutes, and the saw-toothed grain 

 beetle ^ for about 120 minutes. 



EFFECT OF CARBON-DISULPHID FUMIGATION UPON THE GERMI- 

 NATION OF SEEDS. 



It would appear from numerous tests that there is practically no 

 danger of injuring germination in treating seeds that are well ma- 

 tured and dried out before treatment is given. It would not he wise 

 to treat 7noist seeds, or planting seed of any Idnd, during periods of 

 very humid atmosphere, as the seeds might take up enough moisture 

 to make them liable to injury from the vapor. 



SUBSTITUTES FOR CARBON DISULPHID IN FUMIGATION WORK. 



A number of other volatile materials have been tested more or 

 less carefully in the search for a fumigant that would be as effective 

 as carbon disulphicl and safer to handle on account of having non- 

 explosive qualities. Among this number carbon tetrachlorid is prob- 

 ably of largest value, but even with this material it is necessary to 

 use several times as much as is required of carbon disulphid, and the 

 fumigation to be effective is several times as expensive. It does not 

 appear probable that any of these substitutes is likely to come into 

 general use. 



^ PacJiymcrus chineHsis L. " Calandra oryza L. ^ Silvanus surinamcnsis L. 



