68 NATURAL C0XTR0L OF WHITE FLIES IN FLORIDA. 
trace of red fungus present in the experimental block of 26 orange 
trees located in the midst of a 10-acre grove. An examination of 100 
leaves of old growth picked at random from the experimental block 
showed that an average of 12.6 had matured in the spring of 1909 
or were still alive on the leaves as pupa?. The new spring growth was 
beginning to become blackened by May 21 and was generally moder- 
ately blackened by June 15. The experimental block was sprayed by 
the foreman, Mr. John Engle, on May 17, June 9, July 2, August 2, 
September 2, and September 11, using about 2,000 pustules of red 
fungus for the first and about 4,000 pustules of red fungus for each 
later spraying. One hundred and fifty leaves picked at random on 
June 15 had an average of 7 pustules of red fungus per leaf; on 
August 21, 140 leaves had an average of 8.8 pustules, and on Sep- 
tember 15, 50 leaves had an average of 19.6 pustules. On August 2 
Mr. Engle wrote to the effect that the fungus seemed to be working as 
well in other sections of the grove as in the experimental block. At 
the end of the season no difference could be detected so far as showing 
the slightest advantage from the repeated applications. An ex- 
amination of two lots of leaves from surrounding unsprayed trees 
on September 15 and October 18 showed an average of 41.3 and 
14.3 red-fungus pustules, respectively, on lots of 50 and 100 leaves. 
In regard to the record of October, a misunderstanding is involved 
which in the opinion of the junior author renders the record valueless, 
but even if it be accepted the data show that more fungus developed 
on the check trees immediately surrounding the experimental block 
than on the trees to which the spore mixture was applied. 
(6) Keep Grove, Boardman, Fla. Orange trees infested with citrus 
white fly only; cooperative experiment with Mr. B. B. Keep. — The degree 
of infestation in this grove was practically the same as in the Fair- 
banks grove, but there was no fungous infection. A small block of 
36 trees was sprayed. On May 3, a lot of 25 spring-growth leaves 
picked at random from the experimental block showed an average 
infestation of about 50 larvae in the first three stages. Eed-fungus 
spores were sprayed as in the preceding experiments within the first 
10 days of May, June, July, August, and September. On October 25 
an examination of 125 leaves from the sprayed block showed an 
average of 2.2 red-fungus pustules per leaf while from the surrounding 
unsprayed trees an average of 0.3 pustules was found on 134 leaves. 
On September 25 it was noted by Mr. Yothers that 72 out of 143 
leaves examined from the experimental bio ok had considerable sooty 
mold while the remainder were only slightly blackened. 
