Shenandoah herald. [volume] (Woodstock, Va.) 1865-1974, 1897-06-25
THE SAN JOSE SCALE.

IHE DAN UUOL QUILL.
The San Jose scale, as already
sta ed, occurs on all parts of th'
plant, limbs, leaves, and fruit. Al
the plant becomes badly infested
the scales lie very close together
on the limbs, frequently overlap
ping, sometimes with several yOunl
ones clustering over the surface oi
an cid mature scale. The general
appearance which they present Ii
of grayish, very slightly roughen
ed, scurfy deposit. The natural
rich reddish color of the young
limbs Of peach, pear, and apple Is
quite obscured when these trees
are thlckly infested, and they have
then every appearance OF being
coated with ashes. When the scales
are crushed by scTaDing, a yellow
ish, oily liquid will appear, result
ing from the MASKING of the soft
yellow insects beneath the scales.
Examined under a hand lens dur
ing the summer numbers OF the
little Orange.cOlOred Larvae will be
seen running about, and the snowy
white oung scales. Very frequent
ly the scale has marked tendency
to infest the extremities of the
branches and twigs. This is par
ticularly 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 III severe cases the
upper surface particularly becomes
infested, the scales frequently
ranging III two or more quite regu'
lar rows on either side Of the
mldrib. The male scales are more
numerous on the leaves than the
females. The infested Ieaves turn
puTplish brown.
The San Jose scale was formerly
supposed to differ from all Others IN
the peculiar reddening effect which
it produces upon the skin of the
fruit and Of tender twigs. This,
however, sometimes occurs with
other scales, but is a particularly
characteristic feature OF this in
sect, and renders it easy TO dis.
tlnguish. Tue encircling band OF
reddish disc0loratlOn around the
margin of each female scale Is very
noticeable on iruit, especially
pears. This appearance, however,
sometimes so closely resembles the
small spots on fruit produced by a
common fungus, as to require close
examination with a lens to dis
tingulsh 1t. Frnit severely at
tackled becomes distorted, rough.
and pitted, frequently cracking
and may eventually fall premature
Iy or at least become unmarketable.
The camDInm layer of young
twIgs where the scales are massed
together is usually stained deep
red or purplish, and when the scale
Is only scattering 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 facilitating the inspection OF
trees which have been subject to
possible cOntaglon. The almost
microscopic young scale might
easily elude the most careful
search, but the striking circliDg
ring makes them comparatively
conspicuous objects without the
aid of a glass.
IT the tree survives the attack
tue infested wood eventually be-
comes knotty and irregular, partly
from the sappiug Of the juices by
the insect and also without doubt
largely from the poisoning OF the
sap of the csmbIum layer By the
puncfures of the insect, as indlcat'
ed by discoloration. Young peach
trees will ordinarily survive the
scale only two or three years.
Pears are sometimes killed out.
right, but genereIly maintain a
feeble, slckly existence, making
little or no growth for somewhat
longer period.
FOOD PLANTS.
Practically all deciduous fruit
trees are subjected 10 the attacks
of this insect, including also va.
rious small fruits, such as the cur
rant, gooseberry, etc. 1t has also
been found on a great many shade
trees and ornamental shrubs. The
pear, peach, plum, apple, and
Cherry are almost equally liable
. injury. Tho ounce Is appar'
emily more rarely troubled. Not