Weekly journal-miner. [volume] (Prescott, Ariz.) 1908-1929, 1913-06-18
FOR THE
WOODY APPLE APHIS

Arizona wherever apples are grown
Its injuriousness varies greatly ii
different sections being apparently
largely dependent upon soil condit,
ions. The pest may be recognized
from the woolly secretion of wax
which covers the reddish or purplish
brown lice feeding upon either the
roots, tree, trunk or branches. By
feeding upon the roots, the lice pro-
duce abnormal engagements of ir-
regular shape known as gals
which vary in size according to the
size of the root, frequently becom-
ing as large as the fists. Badly in
tested roots become of little or no
use to the tree, and eventually de-
cay with the result that the tree is
mechanically weakened. Fortunately
the insects do not ordinarily infest
the roots to an injurious extent deep
err than 10 or II inches below the
surface and farther from the crown
of the tree than four feet. On the
tree trunks the lice are apt to be
found in wounds, resembling little
tufts of cotton. The smaller branch
es are subject to heavy infestation,
the insects completely covering the
bark with their cottony secretion,
producing a swelling of the twig
which frequently cracks open.
The root infesting form of the
woolly apple aphis is generally con-
sidered to be more destructive than
the form which infests the trunk and
branches. The former thrives only
under certain conditions In a bull
letin of the Colorado Experiment
Station it is stated that loose, por-
Gus soils seem more favorable for
the development of this louise upon
the roots than are the heavier and
more compact soils" According to
the writer's experience, in defining
the characteristics of the soils which
are most favorable for woolly aphis
development, especial emphasis
should be laid upon soils which
crack in drying. Sandy or other
soils which do not crack seem to
prevent the insects from spreading
rapidly to the new root growth. In
addition to the mechanical condition
of the soil, shallow irrigation and
the lack of cultivation are two i'm
portant features which influence
woolly aphis infestation OF the
roots. The two conditions named
tend to the production of roots near
the surface where they are most
easily infested. Fortunately no 9th
er orchard trees than the apple are
subject to injurious attack by the
woolly apple aphis. The insect has
however, been reported as infeSting
pears in slight degree in a few
cases.
The woolly aphis is attacked by
several natural enemies ("LadyI
bugs" "aphis lions" etc. which
need not be discussed here. These
natural enemies usually clean up the
tops of heavily infested trees dur
ing the summer months. Notwith-
standing the assistance of these
friendly insects the woolly aphis is
frequently sufficiently injurious to the
branches OF the infested frees to
justify spraying. The trunks and
b. anches OF the trees may be spray
ed at any time OF the wear when
the woolly aphis is multiplying in
juriously. The best insecticide for
this purpose consists OF "a combin-
alton of soap with a nicotine ex-
tract. Concerning this combination
the following information
is quoted from a recent publication
OF the Arizona Agricultural Expert
ment Station (Timely Hints for
Farmers No. 90:
BLACK Leaf 40, "Nikoteen," and
"Tobacine" are trade names for
three of the best known concentrat-
ed tobacco extracts The first nam
ed is used in Arizona as a sheep
dip and is consequently more easily
than other brands 1t is
guaranteed to contain 40 per cent
nicotine and is retailed in gallon
cans at $3.50 and in half pint cans
at IS cents. While BLACK Leaf 40'
is especially mentioned herein, other
brands OF concentrated nicotine of
equal strength may be substituted in
the recommendation which follow
y teaspoonful of this concentrated
nicotine compound is sufficient for
one gallon of spray. Soap should be
used with the BLACK Leaf 40' at
the rate of one-half ounce in one
gallon of the spray. This is not
primarily for the insecicidal value
of the soap, but for the purpose of
giving the spray better penetrating
and sticking properties. Whale oil
soap, hard laundry soap, or one of
the soap powders Gold Dust, Pear
line. etc.) may be used in The fore
going spray mixture. The first is
the more effective, but has the dis
advantage OF an unpleasant odor.
The soap should be dissolved in
small quantity of hot water, after
which sufficient water is added to
make one gallon. Add to this the
teaspoonful of BLACK Leaf 40". This
insecticide is not always immediate
in its effects, but the thoroughness
OF the work can be judged twenty
four hours after the application is
made"
The proper means of application
OF the spray is no less important
than the composition of the spray
itself. Generally speaking. satisfac-
tory results in combating the woolly