UNIVERSITY OF FLORIDA 
• 4 • 3 1262 09238 7603 
make sure the solvent ie a highly refined greaseless kerosene to 
avoid staining. Within hones sprays are applied lightly or at the 
rate of about 1 gallon per 4,000 square feet of surface „ When used 
on a basement floor the application should be about four times 
heavier than when sprayed on a hardwood floor or rug. Spraying 5- 
peroent DDT solutions to chicken runs and houses for oontrol of 
stioktight fleas has given excellent results. Oil sprays, however, 
should not be used on la-eciS because they will burn the grass. 
DDT in Emulsions 
Emulsions containing DDT can be used in the same manner as the 
DDT solutions with equal effectiveness* 
An emulsion ooncentrate is a liquid whioh on dilution with water 
gives a spray suitable for certain purposes. A very satisfactory 
oonoentrate for making DDT emulsions contains 25 peroent of tech- 
nical DDT, 65 peroent of xylene, and about 10 peroent of a wetting 
agent such as Triton X-100 (polyethylene glyool phenyl isoootyl 
ether). One part of this oonoentrate diluted with 4 parts of water 
makes a 5-percent DDT emulsion* 
DDT in Suspensions 
DDT suspensions are recommended for general use in and about 
farm buildings, in yards, in basements, and other similar situations 
where the unsightly white residue is not objectionable. A 2.5-percent 
DDT suspension is recommended, and it may be applied by means of an 
ordinary hand-operated pressure sprayer. DDT in these suspensions 
settles to the bottom of spray equipment, however, and they sometimes 
olog nozzles adjusted to even a coarse spray. Constant agitation 
will eliminate this trouble and provide for the delivery of a uniform 
concentration of spray material. DDT suspensions are used at the 
rate of about 1 gallon to eaoh 1,000 square feet of basement floor, 
but a larger quantity is needed on lawns. 
The most recent work on residual sprays has led to the develop- 
ment and use of water-dispersible DDT powders, whioh are now manu- 
factured by several oompanies. A satisfactory DDT suspension oan be 
made by mixing a water-dispersible powder containing 50 percent of 
DDT at the rate of 2 pounds to 5 gallons of water. This mixture con- 
tains about 2.5 percent of DDT. If a 25-percent DDT powder is used, 
4 pounds of the powder should be mixed with 5 gallons of water to 
obtain the same concentration. 
