191 



I need not tell you, but it may be well for the information of the public 

 to say (as I have not alluded to the matter elsewhere) that a number 

 of different species of ladybirds feed upon the Woolly Aphis and that 

 it is a rule with the insects of this family not to be select as to the 

 particular Aphid they prey upon. Hippodamia convergens (the species 

 referred to as the Sedan of the Woolly Aphis) feeds over nearly the 

 whole extent of the United States upon this particular Sehizoneura, 

 among others, and the fact that both the species referred to feed upon 

 vaiious aphides is well known. That one of the species is also com- 

 mon upon the Pacific coast and that its being carried there from the 

 East is like "carrying coals to Newcastle" may not, however, be so 

 generally known. All such efforts as this carried on by persons unfit, 

 from want of any special knowledge, for the mission, must invariably 

 do harm, not only because of the negative results which follow, but 

 because of the lack of confidence in such work which they will engen- 

 der in the minds of our legislators. 



I should noi; think of holding any one responsible for newspaper par- 

 agraphs, but in this case the party has substantially confirmed them 

 in statements over his own name and in interviews which (as announced) 

 he has himself revised. 



METHOD OF USINQ BISULPHIDE OF CARBON AGAINST GRAIN WEEVILS. 



The use of bisulphide of carbon against different insects attacking 

 stored grain has greatly increased in this country since I first recom- 

 mended it some thirteen years ago.* There is, however, considerable 

 diversity in the method of using it and the recommendations of some of 

 our writers have evidently been made with no sense of the fact that the 

 fumes are heavier than air and descend rather than ascend. Prof. A. 

 H. Church in a recent number of the Kew Bulletin records that he fouud 

 that ]^ pounds of the bisulphide is enough to each ton of grain. He 

 advises that it be applied in the following way : 



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 then at once plunged into the ves- 

 sel and left there, the muuth 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 When necessary, the stick may be withdrawn and the charge 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 action of carbon bisulphide lasts in ordinary cases six ^eeks, 

 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 germinating power of most seeds is not appreciably affected, pro- 

 vided that not too much is used, nor its action continued for too long a 

 period. 



* Farmers Review (Chicago), March, 1879. 



