Evening star. [volume] (Washington, D.C.) 1854-1972, 1904-11-10
FRUIT TREES INJURED
San Jose Scale Found in This
Vicinity.
DIR. MARLATT'S OPINION
TREATMENT SUGGESTED FOR RID
DING TREES OF THE PEST.
Can Be Checked If Taken in Time
Experiments by Agricultural
Department.

Within the past several weeks number
of fruit growers in this vicinity have found
that the trees have been attacked by the
San Jose scale, which has been the bane
Of the fruit raisers all over the country for
a number Of years past. These insects have
invaded the orchards at many of the sum-
mer and suburban homes Of Washington
of late to such an extent that 1t Is feared
most of the trees will be lost and to save
others can only be done by means decidedly
strenuous. 1t was learned at the Agricul-
tural Department this morning that when
the trees are heavily infested the best thing
to do is to dig them out root and branch.
According to DIR. c. l.. Marlatt, assistant
entomologist of the Department of Agricul-
ture the San Jose scale occurs on all parts
of the plant, limbs, leaves and fruit. AS
the plant becomes badly infested the scales
lie very close together on the limbs, fire.
quently overlapping, sometimes with several
young ones clustering over the surface or
an old mature scale. The general appear
ance which they present is of grayfsh,
very slightly roughened, security deposit The
natural rich reddish color of the young
limbs of peach, pear and apple Is quite OBJ
scured when these trees are thickiy lnfest-
ed, and they have then every appearance
of being coated with ashes. When the
scales are crushed by scraping, yellowish,
oily liquid will appear, resulting from the
MASKING of the soft yellow insects beneath
the scales. Examined under hand lens
during the summer numbers of the little Or
ange-colored larvae will be seen running
about, and the snowy white young scales
will be interspersed with Old brown or
blackened mature scales.
One Characteristic.
Very frequently the scale has a marked
tendency to infest the extremities of the
branches and the twigs. This is particular
ly noticeable with pear. AS usually found
on peach the scale is massed often more
densely on the older growth, and works out
more slowly toward the new wood.
The leaves are much less apt to bear
scales, but in severe cases the upper surface
particularly become infested, the scales fire.
quently ranging in two or more quite regu-
lar rows on either side of the midrib. The
male scales are more numerous on the
leaves than the females. The infested leaves
turn purplish brown.
The cambium layer of young twigs where
the scales are maSSed together Is usually
stained deep red or purplish, and when the
scale Is only scatteringly present the dis
tinctive purpliSh ring surrounding each Is
almost as noticeable on young twigs as on
fruit, and is of the greatest service in ia
cilitating the inspection of trees which have
been subject to possible conta gion. The al
most microscopic young scale might easily
elude the most careful search, but the
striking circling ring makes them compare
lively conspicuous objects without the aid
Of a glass.
If the tree survives the attack the in
tested wood eventually becomes knotty and
irregular, partly from the sapping of the
juices by the insect and also without doubt
largely from the poisoning of the sap of
the cambium layer by the punctures of the
insect, as indicated by the discoloration.
Young peach trees will ordinarily survive
the scale only two or three years. Pears
are sometimes killed outright, but generally
maintain feeble, sickly existence, making
little or no growth for somewhat longer
period.
Deciduous Fruit Trees.
Practical all deciduous fruit trees are
subject to the attacks of this insect, in
Guiding also various small fruits, such as
the currant, gooseberry, etc. 1t has also
been found on great many shade trees
and ornamental shrubs. The pear, peach,
plum, apple and cherry are almost equally
liable to injury. The ounce Is apparently
more rarely troubled.
while one is undoubtedly justified In as
sorting that the San jose scale Is to be a
permanency, 1t by no means follows that
the profitable growth of deciduous fruits Is
seriously menaced on this account" said
DR.. Marlatt. THE experience in California,
covering many years, has abundantly DEM
onstrated that this scale insect can be con-
trolled, and the more recent experience In
the east points Individually to the same
conclusion. In other words, by proper re-
pressive and remedial treatment, the value
OF which has been demonstrated by much
practical experience, an orchard can be pro-
tected from serious injury and kept In g.
good paying condition so far as influenced
by the San Jose scale.
I'm view of this fact, Ii Is certainly very
unwise and wasteful to dig up and burn a
large portion of an orchard because it Is
infested with this scale insect. especially
since the replanted stock. even If clean
when purchased, would, with little doubt,
be in the same condition OF infestation In q
very short time
Remedy Suggested.
''The best means for exterminating the
scale in my Judgment is what is known as
the lime, salt and sulphur wash
Early experiments with this wash threw
doubt on it's efficiency as an insecticide I'M
der the climatic conditions prevailing
throughout the eastern half of the United
States namely, the more frequent rainfalls
at the time when treatment must be made
Our later experience has shown, however,
that If the weather conditions happen to be
favorable in a measure duplicating the con-
ditions on the Pacific coast, this wash Is
perfectly effective in the east, and If ten
days or two weeks of dry weather or In
considerable rains follow treatment very
satisfactory results may be had. Expert
ments conducted in Illinois by Prof. Forbes
would seem to show further that even fair
ly hard rains will not always invalidate
spraying with this mixture, and experience
in Illinois and various Atlantic states has
shown that in the majority of cases this
wash Is nearly as efficient as the treatments
with oil and soap, and has at the same time
the advantages of far less cost than the pure
oil or the soap method and no danger to
trees. 1t is a winter application and may
be applied any time between January and
Just prior to the blooming and leafing out
In spring. February and March are the
best months. The formula recommended Is:
Unslacked lime, 30 pounds; sulphur, 20
pounds: salt 10 pounds. Place all together
In a barrel with 80 or 40 gallons of water
and boil with steam for three or four hours.
For use, the mixture should be diluted to
make 60 gallons of wash, and may be pre-
ferably applied at a high temperature. It
may be made in smaller quantities by boil
ing over a fire, using the same proportion
of ingredients. This wash is applied nearly
every year, or as often as the San Jose scale
develops in any considerable numbers. 1t
has the advantage of leaving a limy coat
ing on the trees, which acts as a deterrent
to the young scale lice, and where it Is not
washed by rains retains its value as an In
secticide coating for some time, remaining
in evidence on the trees for several months.
Soap Wash Good.
Another good treatment Is the soap
wash. whale-oil or fish-oil soap, preferably
made with potash lye is dissolved in water
by boiling at the rate OF two pounds Of
soap to the gallon of water. II applied
hot and on a comparatively warm day In