SMUDGES AND FUMIGANTS. 31 



folium^ and the crop in Dalmatia is comparatively as valuable as the 

 other. Thirty years ago it was considered the most valuable export 

 in Dalmatia. The best powders are made from the dried fiower- 

 heads of these plants, and the essential principle seems to be a vola- 

 tile oil that disappears with age and with exposure. Powders im- 

 ported from Europe are apparently not so strong as powders made 

 in this country from imported dried fiowerheads brought over in 

 bulk. For this reason it was, man}^ years ago, deemed very desira- 

 ble to establish a Pyrethrum-growing industry in the United States, 

 and in 1881 the United States Entomological Commission imported 

 and distributed the seeds of the two species above mentioned to a 

 number of correspondents in different parts of the country. The 

 total success was inconsiderable. Further experiments another year 

 met with comparative failure. About this time more extensive 

 plantations were made in California and an insect powder was made 

 by the Buhach Producing and Manufacturing Company, of Stockton, 

 CaL, which, being American grown and freshly ground, came into use, 

 and is still being produced and sold under the proprietary name of 

 "buhach," the word being supposedly derived from a Slavonic word 

 '^buha," meaning flea. An article by ]\Ir. D. W. Coquillett on the 

 production and manufacture of this powder will be found in a bul- 

 letin^ of this Bureau. 



Most of the insect powders sold in the shops in this country have Pyre- 

 thrum powder as a basis. It is difficult to get a pure and thoroughly 

 efficient powder. There is often adulteration. Frequentl}^ the powder 

 made from the dried flowerheads is adulterated with powder made 

 from the stems, or with other adulterants. Pyrethrum powders are 

 usually used dry and are puffed or blown into crevices frequented 

 by insects, or puffed or blown into the air of a room in which there 

 are mosquitoes or flies. The burning of the powder in a room at 

 night is a common practice. The powder is heaped up in a little 

 pyramid which is lighted at the top and burns slowly, giving oft' a 

 dense and pungent smoke with an odor very much like that of the 

 Chinese punk used to light firecrackers. Often the powder is moist- 

 ened and molded roughly into small cones, and after drying it 

 burns readily and perhaps with less waste than does the dry powder. 

 Of late years in mosquito-infested countries a number of mosquito 

 pastilles have been sold, and many of these are molded from powders 

 that contain more or less Pyrethrum. The efficacy of the burning 

 pyrethrum in a close room is almost perfect. It wfll not actually 

 kill all the mosquitoes, but will stupefy them and cause them to fall 

 to the floor where they may be swept up and burned. With the 

 windows open, however, and the constant currents of fresh air blow- 

 ing through the room, this fumigation is not especially effective, 

 and it is necessary for protection to sit in the cloiid of smoke. 



oBul. 12, old series, Div. Ent., U. S. Dept. Agr., pp. 7-16, 1886. 



