66 NATURAL CONTROL OF WHITE FLIES IN FLORIDA. 
It appears that the great humidity, after the introduction of Sep- 
tember 11, was not a condition which would promote fungous develop- 
ment. The increases in the average number of fungous pustules per 
leaf are, as a rule, inconsistent, in series A and B, whether the data 
be examined from the standpoint of the attempts made to spread the 
infection or from that of climatic conditions. One exception is 
found in the rapid increase between the examination of August 14 
and that of September 11 for both series. This most important 
increase of the year appears to be entirely uninfluenced by the 
attempts to spread the infection, since the fungous pustules in series B 
increased at practically the same rate as in series A. The pustules 
in series A increased about 200 per cent between July 9 and July 24, 
when practically uninfluenced by artificial spreading of infection, 
while the pustules in series B increased only about 60 per cent. 
Between July 24 and August 14 the attempt to assist natural means of 
spread was followed by a 46 per cent increase, while without any 
effort in this direction the natural spread in series B amounted to a 
200 per cent increase in the number of fungous pustules. 
Notwithstanding the foregoing inconsistencies the records show 
that after the initial introduction the fungous pustules multiplied 
about 10 times (964 per cent increase) in series A and about 6 times 
(623 per cent increase) in series B. It is not impossible that such a 
difference as this in the rate of multiplication might be found in two 
arbitrarily selected groups of trees treated identically as regards 
fungous introductions. We may, however, fairly give the fungous 
diseases the advantage of the presumption that the difference noted 
is due to the artificial spreading of the infection. The question then 
arises, Did this difference result in any practical benefit to the trees ? 
On June 30 an examination showed an average of 59 live larvae 
and pupse per leaf in the experimental block; on July 24, 21.5 per 
leaf; on August 27, 43.7 per leaf on old mature growth and about 350 
larvas per leaf on the newer summer growth, and on October 26 an 
average of 27.8 five per leaf. The last estimate was based on 10 
typical leaves which averaged 27.5 red-fungus pustules per leaf and 
10.4 pupa cases. While this examination was not extensive enough 
to compare with those the results of which are given in Table X, a 
summary showing more live insects in the leaves showing the most 
fungous infection is noteworthy. 
Five leaves with greatest number of red-fungous pustules, averaging 47.6 per leaf, 
36 live per leaf. 
Five leaves with least number of fungous pustules, averaging 7.4 per leaf, 19.6 live 
per leaf. 
It is probable that more adults migrated from the surrounding 
trees to the experimental block and from trees of series A to series 
