42 WHITE FLIES INJURIOUS TO CITEUS IN FLORIDA. 
fourth of a mile from any citrus grove, and the junior author has 
made similar observations along roadsides near Orlando, Fla., in 
June, 1909, the insects being in the adult stage only in this latter 
case. On the other hand, the senior author noted on June 18, 1909, 
that wild persimmon bushes growing in a vacant lot with China trees 
and abandoned citrus trees were only very slightly infested, although 
the citrus trees and the China trees were heavily infested. The 
wild persimmon had made vigorous growth, but its white-fly infesta- 
tion consisted of less than 10 eggs per leaf and an occasional adult. 
The examination of leaves of the China tree showed hundreds of 
pupae and pupa cases per leaf, with a few adults and newly deposited 
eggs. The old citrus leaves bore many larvae, pupae, and pupa 
cases, and the new leaves bore hundreds of unhatched eggs. The wild 
persimmon bush was as favorably located with respect to citrus trees 
as was the China tree. Notwithstanding the exceptions noted in 
degree of attractiveness, the Japanese and the wild persimmons very 
evidently rank well below citrus trees, China trees, and umbrella 
China trees. ; 
In so far as observed the persimmons have little effect on the con- 
trol of the citrus white fly, but in special cases they may rank as 
important food plants. The fact that the Japanese persimmon is a 
producer of fruit of some commercial value makes its ordinary light- 
ness of infestation a matter of gratification. The wild persimmon, on 
the other hand, is of practically no value either for shade or fruit, and 
can easily be destroyed where advisable. 
Lilac is not commonly grown in the citrus-growing regions of the 
Gulf States, and on this account, so far as observed, presents no 
element of menace to orange groves. In company with all of the 
ornamental plants listed as preferred food plants this one must be 
considered, however, as undesirable for introduction and growing 
in citrus-growing regions. 
PRICKLY ASH. 
Belonging to the family Rutaceae, to which the genus Citrus also 
belongs, it is not strange that the prickly ash is a favorite food plant 
of the citrus white fly. This plant seems to be highly attractive to 
the adult flies, frequently being observed infested with more adults 
than many near-by citrus trees combined. The prickly ash is common 
in Florida and in some localities, wiiere growing in abundance along 
roadsides, it constitutes a distinct menace to citrus groves through its 
connection with the spread of the white fly from city and town to 
country and from grove to grove. 
