INJURING STORED GRAIN. 233 



soon hatch into legless little larvae that eat out the 

 substance of the kernels, and become full-grown 

 (a) in a few weeks. They then change to pupse 

 and soon afterwards again transform to adult beetles. 

 There are several broods each season. All sorts of 

 stored grain, such as corn, oats, wheat, barley, etc., 

 are attacked by these insects. 



Remedies. — Bisulphide of carbon appears to be 

 the best insecticide to use against grain weevils. The 

 vapor of this substance is poisonous to insect life, 

 and as it is heavier than air it will descend between 

 the kernels of grain, destroying all the weevils which 

 it reaches. Dr. C. V. Riley has lately called atten- 

 tion to the following method of using it, premising 

 with the statement that one and a half pounds of 

 bisulphide is sufficient for each ton of grain : " A 

 ball of tow is tied to a stick of such a length that it 

 can reach the middle of the vessel containing the 

 grain. The tow receives the charge of bisulphide 

 like a sponge, and is at once plunged into the vessel 

 and left there, the mouth or opening of the vessel 

 then being tightly closed. When necessary, the 

 stick may be withdrawn and the charge (of 1 ounce 

 to 100 pounds of grain) may be renewed. The ac- 

 tion of carbon bisulphide lasts in ordinary cases six 

 weeks, after which period a fresh charge is required. 

 The bisulphide does no harm to the grain as regards 

 its color, smell, or cooking properties, and the germ- 

 inating power of most seeds is not appreciably affect- 

 ed, provided that not too much is used, nor its action 

 continued for too long a period." 



