Daily Los Angeles herald., 1882-06-04
THE ORANGE SCALE.
A Valuable Paper from Prof. Riley
on the use of Kerosene to Destroy
the Scale Bug.

The last number of the Scientific
1merican contains valuable contribu-
ton from Professor C. V. Riley upon the
insects most destructive to the orange
and upon the washes which have been
found most potent in destroying the
pests. lie gives the preference to the
kerosene emulsion as an application to
destroy the scale bug, and says: 81 have
for years been endeavoring to solve the
problem of the safe and effective use of
kerosene to plants, because of its well
known superior insecticide qualities, and
now that the problem is solved, the rem
edy will soon find universal application
not alone for the specific purposes here
indicated, but for most of the insect ills
that plants in general suffer FROM"
Here is what he says about the use of
kerosene as an insecticide for citrus trees,
and the way in which it may be prepared
so as to be a safe remedy:
KERosENE.-The value of this sub
stance as an insecticide has long been
known. Of all the light oils which l
have tried, or of which l have any
knowledge, it is the least injurious to
plants of the citrus family. Refined
kerosene, separated from the deadly
naphtha oils, has frequently been used
undiluted without injury. Crude petro-
leum will destroy the bark, and even the
refined oil, if applied in the hot sun
shine, completely defoliates the tree.
Applied in the shade, at sunset, or in
cloudy weather, l have never known
any serious injury to result from its mod
crate use. The tree invariably loses the
old and devitalized leaves, but young
and vigorous growths, especially tender
sprouts and budding leaves, are entirely
unharmed by it. Nevertheless, so many
cases of loss are reported that its use
undiluted must be considered dangerous
In very fine spray, and with proper pre-
cautions, pure kerosene can probably be
used with impunity; but all attempts to
apply it in small quantities, with other
liquids, by dashing them together, should
be discouraged as dangerous, or at best
unsatisfactory, since it is impossible in
this way to secure an even distribution
of the oil to all parts of the plant.
There is, however, safe and ready
method of diluting kerosene and similar
oils, and of rendering them miscible
with water. This method was first in
dicated by me in speaking of the cotton
worm in the Scientific american for
October l6, 1880, as follows:
Nothing is more deadly to the insect
in all stages than kerosene or oils of
any kind, and they are the only sub
stances with which we may hope to de-
stroy the eggs. In this connection the
difficulty of diluting them, from the
fact they do not mix well with water,
has been solved by first combining them
with either fresh or spoiled milk to
form an emulsion, which is easily
effected; while this in turn, like milk
alone, may be diluted to any extent, so
that particles of oil will be held homo
generously in suspension. Thus the
question of applying oils IN any desired
dilution is settled, and something practi-
cable from them may be looked for"
HOW TO PREPARE THE WASH.
Whatever want of success in the at
tempts that have hitherto been made to
emulsify kerosene has been solely due to
the failure to appreciate the true method
of combination and the consequent use
of an imperfect and unstable emulsion.
Mr.. Hubbard has had no difficulty
whatever in making perfectly stable
emulsion, and the secret in doing so
consists in the proper amount of chum-
ing, with the exception that the oil and
milk, in any desired proportion, must be
much more violently churned for peri
cd varying, with the temperature, from
fifteen to forty-fve minutes.
In Mr.. Hubbard's words: ''This is as
| far as the process can be carried on by