36 NATURAL CONTROL OF WHITE FLIES IN FLORIDA. 
produce countless spores. To the casual observer the flies appear 
merely to die and shrivel up on the leaf as shown in Plate IX, upper 
figure. 
In connection with this fungus the authors' observations have been 
limited to the vicinity of Orlando, but Prof. Fawcett, to whom credit 
is due for its determination, has seen it several times working in 
different parts of the State since August, 1908. While it has been 
reported by Dr. Berger x as attacking the larva? of the citrus white 
fly, and has been seen by the authors attacking the eggs of the same 
species, it must be regarded, so far as now known, as primarily a 
parasite of the adult. 
Notwithstanding the very large number of adults it is capable of 
lolling when spreading most rapidly during the fall, it can not be said 
that it has proved itself of any value in checking the progress of fly 
infestation for the reason that a sufficiently large number of adults 
escape to deposit as many eggs as the new growth can well support. 
During September and early October, 1908, when this fungus was 
spreading very rapidly and there were in places from one to several 
hunched dead flies per leaf and it appeared that much good was being 
accomplished, careful examination of the leaves of the new growth 
showed that they were heavily infested with eggs. In a grove near 
Turkey Lake, 8 miles west of Orlando, where the Sporotrichum was 
even more virulent in its attack upon the cloudy- winged white fly, the 
surviving adults so overcrowded the leaves with eggs that on many 
shoots not a larva was able to mature. These observations have been 
mentioned to show that, if anything, the killing of an even compara- 
tively large number of the fall brood of adults may act as a stimulus 
rather than a check to the progress of infestation, inasmuch as it seeks 
to prevent that over deposition of eggs, which, in itself, as explained 
elsewhere, is an important element of self-control with this species. 
Thus far the authors have not been successful in attempts at spread- 
ing the Sporotrichum artificially. During September, 1908, many 
thousand infected flies were collected for experimental purposes. On 
October 8, when the fungus was spreading less rapidly than during 
September, two watershoots were rubbed with infected flies, and 
although adults of both species fed on the leaves for two weeks none 
became infected. One hundred adults caged on a leaf smeared with a 
paste made of 100 infected flies and water did not become infected, 
neither did adults confined on leaves sprayed with a solution of 100 
infected flies in one-fourth of a cup of water. Experiments with the 
same material on May 29 and August 17, 1909, gave equally negative 
results, although adult citri were abundant on the treated leaves. 
Leaves of china tree and orange were dipped and sprayed with a water 
solution of infected flies, were rubbed with a paste made of flour and 
i Bui. 97, Fla. Agr. Exp. Sta., p. 56, 1909. 
