Press Bulletin No. 13.
December I, 1901.
Treatment for San Jose Scale.
(H. A. GOSSARD, ENTO. FLA. EXP. STATION.)
San Jose scale is now known to be established in
about thirty local centres well distributed over the greater
part of the State. The real distribution of the insect
must, of course, be much greater than our records show,
since we are largely dependent upon incidental reports aid
inquiries addressed to the Station for our information;
and it is a fair conclusion that the greatest percentage
of cases are not reported.
The most satisfactory treatment for this insect, so
far as the tests of the Station go and the experience of
correspondents proves, is by a spray of mechanical mix-
ture of crude petroleum and water. Crude petroleum
may be obtained from the offices of the Standard Oil Co.,
Jacksonville, and when intended for insecticidal use,
should be specifically designated as wanted for such pur-
pose when ordered, and should be guaranteed to be of
48 to 45 degrees specific gravity on the Beaume oil scale.
The oil can best be applied with "kerowater"
pump, especially designed for the purpose, and regulated
by a guage to throw any desired percentage of oil.
Two of the most reliable Kerowater pump companies
are the Gould Manufacturing Co., Seneca Falls, New
York, and the Deming Co., Salem, Ohio.
The pump should be guaged to throw about 20 per
cent. of oil, and as these pumps do not always work with
perfect accuracy, some of the mixture should now and
then be pumped into a glass graduate and allowed to
stand for two or three days, until the oil and water sep-
arate, when the actual percentage of oil thrown can be
observed, and future adjustments of the pump made
accordingly. Even 40 per cent. of oil is not apt to injure
dormant trees, but so much is unnecessary and perhaps
Two or three spraying should be given during the
winter. If two are given, the first may be made. some
time during the first three weeks in December and the
second during the latter part of January. If three are
made, the first ihay be given during the last week in No-
vember, or the first week in December, the second about
the first of January, and the third during the last week
in January, or, at least, before early blossoming begins.
Two or three applications, if thoroughly made, will al-
most exterminate the scale. Care should be taken not to
allow too much liquid to collect at the bases of the trees.
It is a good precaution to bank loose earth about the
feet of the trees to absorb the surplus spray and to
remove it at once after spraying. If summer treatment
is needed, refined kerosene must be used instead of petro-
leum, setting the pump guage at about 10 per cent.
For one already having an ordinary spray pump, ker-
8sene emulsion made after the usual formula will be found
very satisfactory. Apply preferably on sunshiny days
and bank the trees as above directed. The emulsion may
be used in either winter or summer.
SThe whale oil soaps are very satisfactory for winter
treatment and the whale oil soap compounds for summer
treatment. Good's.Potash Whale Oil Soap No. 8, Leg-
gett's Anchor Soap and Leggett's Whale Oil Soap Com-
pound are very reliable brands. Full directions for use
accompany these soaps. Soap applications are more ex-
pensive when used on a large scale than kerosene or petro-
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