32 
FLORIDA STATE HORTICULTURAL SOCIETY 
fungal threads interfering with, the 
healthful action of sunlight on the leaves. 
The appearance of the various ornamen¬ 
tal and hedge plants is also disfigured by 
the dark fungus. The sooty mold is es¬ 
pecially bad following the white fly at¬ 
tack owing to the large amount of honey 
dew secreted by these insects. As the 
white fly larvae attach themselves to the 
under side of the leaves the honey dew 
exuded by them falls to the top side of 
the leaves beneath, thus affording favor¬ 
able opportunity for the growth of the 
fungus. So constant is the association of 
the fungus and the white fly that badly 
infested groves and hedges may be recog¬ 
nized at some distance by the heavily 
coated dark foliage. The fungus develops 
on the fruit as well as on the leaves and 
stem and washing becomes necessary, re¬ 
sulting not only in an added expense, but 
also in increased danger of decay in ship¬ 
ping. In this connection the habits of the 
tree snail, Bulimulus Dormani, are of the 
greatest interest. This snail has been 
found in the orange groves in Manatee 
county feeding upon the sooty mould. 
Just how long the snail has been present 
on orange trees in this county it is im¬ 
possible to say. It was observed as long 
as two years ago by Mr. F. D. Waite, at 
Palmetto. It seems to have been present 
in small number in other groves at this 
time, but attracted no further attention 
until the present summer. The snail is 
now widely distributed in Manatee coun¬ 
ty, occurring in many groves on both 
sides of the Manatee river. The work of 
the snails is very characteristic. When 
well started they occur in great,, numbers 
on the tree spreading over it from base to 
top. Its favorite food seems to be the 
sooty mold. The fungus is cleaned from 
the leaves, stems, and fruit. The leaves 
thus cleaned have a glossy, shiny appear¬ 
ance as though free from white fly. The 
fruit thus cleaned has a better color and 
probably ripens earlier. In addition to 
the fungus, the snail takes algae and 
some lichens from the stem and trunk, 
giving the trunk a much cleaner and 
fresher look. The trees that are cleaned 
stand out conspicuously from the sur¬ 
rounding trees by their bright foliage and 
clean trunks. The snails increase rapidly 
under favorable conditions. The eggs are 
probably deposited in protected places 
about the trunks of the trees, possibly also 
about the base of the tree under leaves 
* 
and other rubbish. That the snails are 
capable of doing effective work when 
present in sufficient numbers has been 
shown in numerous groves in Manatee 
county during the present summer. Such 
trees in these groves as are well stocked 
with the snails have been thoroughly 
cleaned, the fruit not requiring washing. 
The snails are of medium size, measur¬ 
ing, when full grown, three-fourths to one 
inch in length. The shells are smooth, 
white, or corneous white, and with about 
four bands of brown spots. Old shells 
have often a somewhat corroded surface, 
the bands becoming indistinct or absent. 
When the conditions are unfavorable, eith¬ 
er cold or dry, the snails take refuge in the 
hollows of the trees or under leaves ac¬ 
cumulated in the forks, or elsewhere, or 
under sacks at the base of the trees when 
these are provided. It thus becomes an 
easy matter to transfer them from tree to 
tree. A few snails placed by Mr. Wade 
Harrison in one of his trees in March, in¬ 
creased in such numbers as to free the tree 
of sooty mold by mid-summer of the same 
year. The snails are known to range 
with some variation from the mouth of 
the St. Johns river on the north, to the 
