10 
FUMIGATION WITH TOBACCO PREPARATIONS. 
Tobacco extracts and fumigating powders have been extensively 
used for a number of years by florists as fumigants against aphides 
and other insects occurring in greenhouses, such as white fly, thrips, 
and other small, delicate, and soft-bodied insects. The extracts con- 
tain a larger proportion of nicotine than ordinary decoctions prepared 
by steaming waste stems and powdered tobacco, and are therefore 
much more effective, which is true also of the powdered forms of nico- 
tine. A number of these preparations are on the market and are 
advertised in the principal florists’ journals and in other agricultural 
periodicals. They are used in various ways, and directions are fur- 
nished with the packages purchased. The liquid preparations vary in 
strength from 35 or 40 per cent up to 80 to 85 per cent nicotine. 
FIELD FUMIGATION WITH TOBACCO. 
During the years 1904 to 1906 the employment of tobacco or nico- 
tine preparations in destroying the melon aphis in the field was the 
subject of experiment in Texas by Messrs C. KE. Sanborn and E. D. 
Sanderson.” These have stated to the writer that, judging from their 
experimental use of this method and its practical use by extensive 
erowers, it bids fair to become the best method of dealing with the 
melon aphis in its occurrence in the South. The process is in briet 
the fumigation of a dry preparation under a cloth-covered frame 
placed over the affected vines. In 1905 and 1906 the writer found 
that a very short exposure to tobacco fumes killed aphides, when other 
insects, such as thrips, survived a considerably longer treatment. 
In practising this method Mr. Sanborn has used apparatus substan- 
tially as follows: 
Preparation of the frame and cover.—For vines 2 or 3 feet long he 
advises a light frame 4 by 6 feet, supported by legs 8 inches in length. 
Lumber three-fourths inch thick and 2 inches wide is suitable. 
Strengthen the frames by connecting the ends with acrosspiece. “Two 
diagonals are also used for strengthening the frame and for conyen- 
ience in handling, the latter being attached after the cloth cover is in 
position. The cover is of muslin of a cheap grade (7 or 8 cents a 
yard) and sufliciently compact to prevent a passage of gas thru its 
meshes after being oiled. Its size should be about 2 feet wider and 
2 feet longer than the frame which it covers. This is sufficient foran 
S-inch wall and a 4-inch lap to the ground. Dirt is placed about the 
bottom to keep the gas from escaping there. 
After the cloth has been cut and sewed into the sizes desired it is 
satur ated in a vessel of linseed oil whic h fills the pores. It is then 
a An experiment with tobacco smoke as a ‘remedy for this species was made by 
Dr. 8. A. Forbes in 1882. The result was not a perfect success, for the reason that a 
bee smoker was used and the smoke was blown under canvas hay caps coyering the 
affected plants. ~Nevertheless from 50 to 75 per cent of the aphides were killed by 
10 minutes’ exposure. 
