The Arvada enterprise., 1911-08-03

Of Microweisea feeding on them, and
the calyx. All greatly enlarged From
CBy A. l.. oUAINTANCE. United States
Department of AgricultureD
| The San Jose or Chinese scale CAS-
| pidiotus perniciosus Comstock) infests
practically all portions of its host
| plants that are above ground-the
trunk, limbs, and branches-and when
abundant it may occur on the leaves
| and fruit. Injury results from the ex-
traction, by the scale insects, of the
juices of the plant. At first this mere
| ly checks growth, but as the insects
increase in number the speedy killing
of the branches and twigs follows, re-
sulting finally In the death of the
! plants. In addition to the extraction,
by the scales, of sap as food, the pune
| turing Of the bark by the slender
sucking mouth-parts results in dis
eased and often pitted condition; the
| inner bark, or cambium, showing a
reddish decoloration, as exposed in
cutting with knife, and the bark it.
self may crack, in stone fruits exuding
drops of masses of gum. A redden-
ing effect is also much in evidence as
red rings around the scales on the
bark, especially of the apple and pear,
and on the fruits of these plants,
though not characteristic of any one
scale species.
On peach the scales have a tendency
to infest to greater extent the older
limbs and branches than the newer
growth, as the wood / year old. On
apple and pear, the terminal twigs
are quite generally infested. and
many Of the young may find their
way to the fruit, settling principally
Ii. the calyx and stem cavities. Most
varieties of fruit trees and plants in
tested from the nursery, in the alb
sence of treatment perhaps never
reach fruiting condition. Peach trees
will usually be killed in two or three
seasons, while pear or apple trees will
maintain feeble existence much long
er. This insect, on account Of It's
great similarity to certain other spe-
cies of scale insects, may be posi-
lively determined except by specialists.
The occurrence of diseased and dying
branches showing severe scale infes-
tation furnishes strong presumptive
evidence of the presence of this pest,
lively determined except by specialists
but specimens of infested twigs should
be promptly submitted to a qualified
person for examination.
The San Jose scale is subject to at
tack by numerous predaceous and
parasitic enemies, which render i'm
portant service in its control. Prac.
tically, however, the combined infu-
ence of these several agencies is not
sufficient to make up for the enormous
reproductive capacity Of this insect
To preserve the plants from destruc-
tion. It's control must be accomplished
by artificial means, such as the use
of sprays.
Among the more common predace-
Gus insects which are observed feeding
on the scale is the o-called pitlful lady
bird (Microweisea Pentilia misella
Lec), shown in the illustration. This
very small, convex, black beetle may
generally be found by any observant
person on scale-infested trees.
The San Jose scale, in the absence
of proper treatment, will quickly
bring about the death of most plants
of economic importance. Its discov-
cry, therefore, whether in orchards or
on priced fruit trees and other plants
In the yard, should call for prompt
steps to effect It's control. 1t has been
amply demonstrated that the scale
may be very successfully controlled,
and practically It's presence requires
one thorough treatment during the
dormant period each year. On ac-
count OF the general distribution of the
pest, determination is in most cases
out Of the question.
Where plants are thoroughly in
crusted, with consequent death OF
branches and stunting Of growth, II
will generally be advisable TO dig out
the trees at once and replace with
new ones, Previous to spraying in.
tested trees the dead and weakened
wood should be pruned out, which Will
simplify the work Of spraying and will
hasten the formation OF new sound
wood.
There are several scale washes
which may be employed In the control
of the insect. and the one should be
selected which can lie most convent.
emily used and which is economical
under the circumstances. Thus for
spraying on a large scale the orchard