54 NATURAL CONTROL OF WHITE FLIES IN FLORIDA. 
Examinations by the junior author have shown that even a larger 
percentage of spores may be lost. It was found that a closely 
woven cheesecloth removed as high as 73.8 per cent to 92.8 per cent 
of the spores, while an ordinary coarse towel removed 41 per cent. 
In obtaining these results one-tenth cubic centimeter of solution of 
red Aschersonia spores and water was placed on a glass slide marked 
off into one-tenth millimeter squares, and the counts made beneath 
a compound microscope. While the results thus obtained were 
subject to much variation, they all demonstrate that cloths should 
be avoided as strainers. Similar examinations of solutions strained 
through fine-wire strainers showed that practically no spores are 
lost. 
Amount of fungus to use. — Experiments to determine the most 
economical amounts of fungus to use per gallon of water have given 
such varying results that no dependence can be placed upon the 
data obtained. Even under identical and apparently most favorable 
weather conditions, in experiments conducted at the same time and 
on trees equally well infested and favorably located, frequently as 
good infections have resulted from the use of 200 pustules as from 
4,000 pustules per gallon of water. This is equally true of results 
obtained when only a few or a larger number of trees were included 
in the experiments. Within reasonable limits, the amount of pus- 
tules to use, therefore, depends entirely upon the amount of fungus 
obtainable. In all of the experiments herein reported, unless other- 
wise stated, 200 or more pustules have been used to each gallon of 
water. 
Advantages of soaking fungous pustules before shaking or stirring. — 
A series of experiments in winch the fungus was allowed to soak for 
different periods between 5 minutes and 48 hours showed that it is 
immaterial how long the fungous pustules remain in the water before 
shaking, provided, of course, that they are not left soaking an unrea- 
sonable length of time. Experiments have furnished no data to even 
warrant any soaldng of the fungous leaves if they are comparatively 
fresh, except such as takes place during shaking or stirring. As good 
infections have been secured repeatedly when pustules were shaken 
as soon as placed in the water as when soaked several hours. 
Number of times fungous pustules can be used to advantage. — Several 
experiments have been conducted to determine this point with definite 
results. Twelve hundred and 1,800 pustules of red Aschersonia in 
different experiments were shaken with a quart of water in a 2-quart 
glass jar for a period of five minutes. After pouring off the water 
used in the first shaking, fresh water was added and shaken as before, 
repeating up to four times. The quart of water used in each succes- 
sive shaking was diluted to make 4 gallons of spray and applied to 
a given number of trees. In every test the third and fourth shakings 
