Sacramento daily record-union. [volume] (Sacramento [Calif.]) 1875-1891, 1886-05-15
W00LLT APHES.
THE WORST KNOWN ENEMY OF
APPLE TREES.
The Most Effective Methods Ascer-
tanned for Its Extermiaation-
Resistant Stock.
IBy W. C. Kee. state inspector of Pests

IBy ". G. Klee. state Inspector of Pests
Among the many diseases to which the
apple tree is subject, ncsae is so persistent
and hard to eradicate and more wide
spread than the woolly aphis, .Sctisoncasrs:
Sanigerd- The home of this pest seems to
to be obscure. In England it is supposed
to have come from America, and there it
goes under the name of American apple
blight. 1t IS found in France and Ger
many, and wherever met is regarded as
one of the most formidable of pests. The
Chilean Consul of San Francisco stated
several years ago that in Chile It had de-
stroyed whole forests of the wild apple.
1t seems almost unnecessary to describe
this pest, unfortunately so common, yet a
few words to noyices in horticulture will
not be out of place. In form, the woolly
aphis resembles closely the green aphis. SO
common on roses and other plants, but its
color is reddish brown, and when crushed
it yields red juice. hence the German
name Blaldus, or blood louise. The in
sects are always surrounded by a whitish
woolly substance, hence the name
% woolly" aphis. Like all aphides, this
species
INCREASES WITH ASTONISHING RAPIDITY,
And only a few need be left on a tree, to
spread all over it. While the presence of
the woolly aphis makes itself so conspicu-
Gus above ground, on the branches, cover
ing them as if with snow. yet the most Sc
ri0I4g trOuhla lies nut Of Gipbt or ba ronts
which in our dry climate they inhabit as
freely as they do the branches, sapping the
vitality of the tree to such an extent that
the fruit becomes small and valueless. If
allowed TO go on unchecked the trees grad
ually die. To the apple tree the woolly
aphis is what the phylloxera is to the
grapevine, sucking and causing swellings
and knobs all over the roots, as well as at
the root crown.
A pest as serious as this has naturally
been long fought, and many are the RENE
dies suggested for its determination. When
young trees first become infested, and it is
discovered in time, number of remedies
may be effectively used.
Rubbing or brushing kerosene on the in
tested spots, or washing them with I've, 2
pound to the gallon, or with strong solu-
ton of whale-oil soap. or uipho-carbonate
of potassium, may effectually arrest the
disease. When, however, the roots of a
large tree once become thoroughly infested
land in this State, unfortunately, that re-
quires but little time), almost all the rene
dies usually recommended prove wholly
insufficient, and on large scale impracti-
cable. For number of years we have
tried at the experimental grounds of the
University various remedies, including to-
bacco decoction, hot water, common lime,
ashes, bisulphide of carbon, and several
proposed remedies of unknown compost
lion, furnished by outside parties. OF the
latter that of Mr.. Lille, of San Francisco.
appears, SO far, quite promising We must,
however, reserve our judgment for some
time yet.
USE OF GAS LINE.
On whole, we have found no remedy
as inexpensive and efficacious as gas lime
the refuse of gasworks. Outside of its
penetrating odor this material has but one
obiection-it is a strong medicine that
must be used with care and the dose must
be regulated somewhat according to the
soil and subsoil, and the age of the trees.
There is necessarily some difference in its
strength, according to its freshness, as it
gradually loses some of its ingredients by
exposure to the air, and especially to rain.
Nevertheless, when applied to given spot,
1t will retain its efficacy for at least three
years. Our first experiments with it began
four years ago, and at the Convention held
in San Francisco that year / made my first
statement in regard to this remedy. |
stated that marked effect had been pro-
duced by it, and that the aphis had been
killed, but that in spite of the very strong
dose applied to each tree-something like
ten pounds-the insects were again de-
scending to the roots. | stated, also, that
some of the trees on shallow soil had been
killed by the gas lime, and that on the
whole, the remedy was not satisfactory.
During the succeeding spring and summer.
however, | gained fresh confidence in it. as.
with the exception of very weak trees or OF
these in shallow soil. comparatively few
died, those less injured showed returning
vigor. The gas lime had also been very
beneficial to the soil, causing the heavy,
stiff loan to pulverize like ashes. The next
season, after the first rain, | noticed the
peculiar, strong odor of the gas lime Ex-
animation later on, in the spIing showed
that the aphis was not to be found about
the roots, and existed right at the surface
only. 1t evidently had not gained any
Roadway. Altogether, the remedy now
looked so promising that it was decided to
give ii a trial on larger scale, but in much
smaller doses these, if proving sufficient,
to be increased the next year. The call to
take charge of the collection of plants for
the New Orleans Exposition prevented me
from carrying out my intentions at the
time, and it was not until the past season
QSS5-6) that experiments properly guarded
could be made.
THE FIRST RESULTS.
The bad effect of the first application was
to corrode the bark ON the younger trees,
causing it to decay. Instead of removing
the soil and putting the gas lime in close
contact with the tree, as was done the first
time, there was spread about a shovelful
and half, l. C., about two or three pounds
in a dry state, within radius of four feet
over the surface around the tree, trusting
10 the rain To wash it into the soil. To
prevent the aphis from remaining close on
the root crown, fresh ashes, few shovel
fuls to each tree. were piled close about the
trunk. The work was done early in Octo-
Der, and the copioUs rains of the season
gave good opportunity for action.
On the trees examined thus far, the re-
suit has been very satisfactory. They show
by the knots and swellings on the roots,
that they were once badly infested still
there IS no aphis on them now, while on q
few other trees left without treatment the
insects are crowded. Two rows of trees
treated several years ago and now treated
again, but having had no ashes placed
about them, show the aphis working down
ward again. To make the work complete
therefore, 1t seems necessary TO use ashes OF
some similar material close about the root
QUANTITY TO BE USED.
The dose of gas lime to be given to tree
should vary according to its size and age
and the nature of the soil. In a porous
deep soil, there is less danger of injury
than in clayey one, where the water
charged with the antidote permeates the
soil very slowly, and has time to corrode
the bark. In the case of some old trees in
the Santa Cruz mountains treated last sea.
son, according to our. suggestion, although
the gas lime had been put right on the
roots after the soil had been taken away
the roots were perfectly sound and all the
aphis killed. The soil was a sandy loan
underlaid by limy sandstone. Thus, the
exact dose TO be recommended is a little
difncult to determine. Il is always safe tc
use small dose first-fron one shoyelful
on small tree, to four on very large one
spread over the surface. according to the
right. W NUM-
IL should be stated that thorough treat
ment OF the top was never made because
we wanted to see how far we could denend
upon the lady-bug for determination tbere
From observations during the last faw
years, ! believe that in this locality this