94 HOUSEHOLD INSECTS 



made is grown in California and the product is known as 

 buhach. Buhach, pyrethrum, Persian insect powder, 

 and Dalmatian powder are practically the same thing. 

 They consist of the finely ground or powdered flower 

 heads of certain species of chrysanthemum, Pyrethrum 

 cineraricefolium and P. roseum. 1 



It is difficult to secure pure pyrethrum from the drug 

 stores. It is apt to be diluted with various substances 

 that have no value as insecticides. However, the pyre- 

 thrum powders are used a great deal for fighting house- 

 hold insects, especially flies and mosquitoes. Usually 

 the powder is blown into cracks and crevices frequented 

 by the pests. The burning of the powder in rooms as 

 a fumigant is also quite often practiced. The powder 

 may be burned on coals or it may be heaped in little conical 

 piles, which when lighted at the top will burn. The odor 

 of the burning pyrethrum is inoffensive to most persons 

 although with some individuals it may cause headache. 

 When burned in a closed room, it will stupefy all of the 

 mosquitoes. It does not actually kill all of them and they 

 have to be swept up and burned. The odor of the burning 

 powder will give relief from mosquitoes on open porches 

 or in open rooms, but in order to receive the benefit one 

 has to sit in the smoke. A pound of the powder to 1000 

 cubic feet of space has been recommended as necessary 

 to accomplish the desired results. This makes such fumi- 

 gation rather expensive, and because the powder does not 

 actually kill the insects, sulfur is used more extensively. 



Sulfur. — On account of its cheapness and effectiveness, 

 sulfur is the most desirable fumigating substance for mos- 

 quitoes. The room in which the fumigation is to be done 



1 Now put in the genus Chrysanthemum. 



