NATUBAL EFFICACY OF FUNGOUS PARASITES. 
43 
Table IX. — Status of white files and their fungous parasites in eight groves, December, 
1908, to December, 1909. 
Examination, December, 1908. 
Examination, July, 1909, 100 
leaves picked at random from 
each grove; condition as to 
sooty mold . 
Examination, December, 1909. 
Grove 
No.i 
Average 
number 
forms 
per leaf. 
Average 
number 
live forms 
per leaf. 
Average 
number 
forms 
killed 
by fungus 
per leaf. 
Average 
number 
forms 
per leaf. 
Average 
number 
live forms 
per leaf. 
Average 
number 
forms 
killed 
by fungus 
per leaf. 
1 
3 
4 
5 
8 
103.7 
108.3 
132.6 
229.2 
597.3 
282.4 
469.4 
229.9 
49.1 
32.0 
20.0 
35.9 
30.6 
8.4 
1.7 
8.3 
24.5 
1.7 
19.2 
29.6 
80.9 
43.9 
84.2 
9.7 
All leaves thoroughly blackened. 
79 per cent moderately blackened. 
60 per cent moderately or slightly 
blackened. 
64 per cent thoroughly, 34 per 
cent moderately blackened. 
170.0 
124.4 
106.2 
218.5 
82.3 
48.7 
56.8 
27.8 
0.5 
13.0 
6.8 
13.8 
11.9 
4.9 
3.9 
2.5 
56.6 
12.4 
14.0 
26.0 
13.4 
9 
3.1 
10 
11.6 
12 
8 per cent moderately blackened, 
remainder showing traces. 
3.6 
See Table II. 
As regards blackening of the fruit and foliage, which is the most 
important element of injury by the white flies, groves 1, 3, 4, and 5 
were not benefited by the work of the parasitic fungi during either 
1908 or 1909. By the 1st of July, 1909, these groves were at least 
as black as the average infested grove in which no fungous parasites 
were established. Moreover, there were sufficient live insects present 
to continue this condition regardless of any unusual climatic condi- 
tions which might favor the multiplication of the fungous diseases. 
As regards the reduction of the insects themselves, the fungous diseases 
were decidedly effective in grove No. 1, promising a condition of 
freedom from white-fly injury in 1909. The condition of groves Nos. 
3 and 5 did not give promise of such condition, since any number of 
live white flies (pupas) above 10 per leaf in December is strong indi- 
cation that the insects will multiply sufficiently the following spring 
to cause a decidedly injurious blackening of the foliage and fruit 
before climatic conditions will give the fungous parasites an opportu- 
nity to check them. Without interference by adults migrating from 
other groves, an average of 12 overwintering insects per leaf has been 
noted to produce a general blackening (moderate) of new spring 
growth of foliage by June 15, while an average of 2.6 live insects per 
leaf in December was noted to result in a very heavy infestation one 
year later with excessive blackening of the foliage. As is often the 
case, in this latter instance the foliage appeared entirely clean up to 
midsummer, most of the blackening appearing in September and 
October. 
On the July examination of No. 4 it was found that the average 
number of forms per leaf representing the insects which produced 
the condition noted consisted of 26 dead larvae and pupae, 8.8 live 
larvae and pupas, and 1.9 pupa cases. No. 8 was in a satisfactory 
