20 farmers' bulletin 709. 



It is a good plan to provide for this treatment, which is needed in 

 every hom-e, by having an especially large, gas-tight and insect-tight 

 packing chest with a very closely fitting cover. A hole should be 

 bored through the cover and a small sponge, bmich of cotton waste, 

 or similar absorbent material fastened below the opening on the 

 inside. The chest may then be kept tightly closed and the carbon 

 disiilphid applied by pouring it through the opening, which there- 

 upon is closed with a cork. The small cost of such an arrangement 

 will soon be balanced by the convenience and security of the protec- 

 tion afforded. Carpets, rugs, blankets, woolen clothing, furs, etc., 

 can be rid surely of all insect pests by inclosu-re for a few daj^s in such 

 a box. The dose used should be at the rate of at least 10 pounds to 

 1,000 cubic feet. 



Among the numerous insects found in houses there are few that 

 may not be reached successfully with carbon disulphid applied as 

 directed for the fumigation of buildings. (See pp. 12-14.) Cock- 

 roaches, croton bugs, bedbugs, fleas, carpet beetles, etc., all can be 

 destroyed by proper use of this liquid. The holds of large ships 

 frequently are cleared of such pests, and also of rodents, in this 

 manner. 



DESTROYING MUSEUM PESTS. 



Carbon disulphid is used very generally for the destruction of a 

 number of insect pests which ruin museum specimens. Such speci- 

 mens usually are inclosed in fairly tight showcases, traj'^s, or boxes, 

 and these can be treated rapidly and successfully simply by inserting 

 the necessary amount of liquid and then closing doors or covers 

 normally. In this way many museums are treated regularly as a 

 measure of precaution, even though no pest is known to be present. 

 Sometimes specimen trays or materials are placed in especially con- 

 structed, tight rooms or chests within which one general treatment 

 reaches all of the contents. AVith this method care must be taken 

 to see that boxes and trays are opened so that the vapor can diffuse 

 through all of them. 



SPECIES FACTOR IN INSECT RESISTANCE TO CARBON 

 DISULPHID. 



Great variation has been fomid in the resistance of different species 

 of insects to carbon disulphid fumigation. This may be spoken of 

 as the species factor and should always be considered in such work. 

 Just as in the case of ordinary insect-killing bottles in which sodium 

 cyanid is now used, the bumblebee probably is the easiest insect to 

 kill with carbon disulphid. In a saturated atmosphere of disulphid 

 at about 90° F. a bumblebee will die in a few seconds, while under 



