The herald., 1897-09-09
The Black Scale

Inc BLACK SCale
Beyond any question the black scale
lecanius oleae, is now by far the mos
destructive insect in Southern Califor
mia. Though not SO much to be dreaded
as either the purple or red scale, wher
once in an orchard it is so much NOR.
widely distributed that the proportion o
damage in this great fruit region !!
greatly on the side of the black scale
There is not a county and scarcely ;
fruit district in our whole section tha
does not show in some orchards ant
often in many orchards great injury
Black scale also infests so many kind:
of plants, all the citrus group the olive
o!eander, and many deciduous trees
All scale insects secrete more or less 8
sweet exudation known as honey dew
When this is very abundant it attracts
a fungus, which is black, and gives tt
the branches, the foliage, the fruit
whatever it overspreads-a black, re-
pulsive. unhealthy look We have no
scale in Southern California that is more
productive of this honey dew than is the
black scale. Indeed this might be re-
garded better reason for its name than
its own color, for it is only black when
old, and even then often more brown
than black, unless this same black for
bidding fungus has fastened upon it,
This disagreement of fruit and foliage
adds another serious count against the
black scale. Thus, from its wide diStri-
button and the serious harm that results
from its attack, we are quite JUSTIFIED
In regarding it as quite in the lead of all
our scale pests, indeed of all our insect
foes.
A BRIGHTER SIDE
But the facts regarding the black scale
are not all of blackest hue. There are
two features in its life history that rem
der its destruction. easy and sure, and
thus the careful orchardist is not as one
without hope. The orchard, foul with
the work of this foe, is simply label of
it's own owners neglect or ignorance.
There are two types OF scale insects in
regard to the makeup of the scale itself.
In the one type the scale is the insect.
That is, the insect is fiat and scale-like,
and at maturity covers from one to
three thousand eggs with its own body.
To this-type belongs the black scale, the
prune or frosted scale, the brown or soft
brown scale, the hemispherical scale,
lecanium The cottony cushion sca.e
also belongs here. In the other group
the scale is no part of the living insect,
All insects, during their growth, moult
or shed their skins. These cast-off skins
are called eXuviae. These scale insects
use two of there eXuviae as a nucleus
to build around and thus form a very
close, impervious scale. They secreta
a compact, fbrous material which bor-
ders the exuviae, and with them COM
pletes the close-fitting, waterproof COW
ers.
Thus when we use a pin or point of
knife blade to raise these scales, we do
not raise the insects, but only nicely
finished protecting cover, and by close
observation we will notice the minute
insect still under the place from which
the scale was removed. Here, then, the
insect as well as the eggs are covered
and protected by the scale. To this group
belong the pernicious or San jose scale,
the red scale, the yellow scale,
the purple scale, the rose scale-indeed
all the Genera Aspediotus, Myltilaspis
and Diaspis, as also some others. We
see that the first group are much less
protected than the second. Remedies
applied to them have not to penetrate
well fashioned shield before they affect
the insect. We treat the insect when We
attack the scale. In the other case we
must break through the we'll made ar
NOR to reach the insect. Any substance
that will not penetrate the scale will be
powsrless to disturb or injure the insect
beneath We thus see that the purple
and red scales are by nature protected
and much more difficult to destroy than
are the black and prune scales. Thus in
fumigation or in the use Of sprays sue
cess may attend treatment of the black
scale, While the purple or red will be
entirely uninjured. Everyone knows that
fumigation thoroughly done and at the
right season is a very complete remedy
or core for the work of the black scale
while one of the horticultural commits
Nioners Of Orange county says it is no
cure at all for the purple scale. though
Mr. Copeland of Chula Vista believes
that fumigation may be so we'll and
thoroughly done as to extirpate the pur-
pie scale. However this may be. there
can be no question but that the black
scale is far more susceptible to rene
dial treatment than is the red or purple
Again. there. are two types of scale
insects, with reference to their reproduc-
ton. One group is oviparous-that is
they lay eggs. If we raise black scale
In May and June we may find s many
as 5000 eggs underneath. These will
hatch in late June and July; and so ir
August and surely in September. nearly
all the Insects on the trees will be young
To this group belong the black the pur-
pie, the frosted and the cottony cushion
scales. Other scale insects are ovovivi-
parous-that IS, the eggs are hatched
within the mother scale and so the
young are born alive. as we may say. or
active. We never see eggs under the San
Jose, the soft brown or the red scale
II we carefully dissect the mature in
sect we will find young insects. within
the mother insects
To this group belong the soft brown.
the red, the yellow and the San Jose
scale insects. In this case the mature
insect will be giving birth to young in
sects for days and even weeks The San
jose scale will be six weeks in delivering
all her large brood of young Thus. as
will be evident. there will be all sizes
and all ages, from tiniest broodling to
Oldest mother, on the tree at the same
time and at all times during the warm
growing season of the year, which is
nearly the entire season here in Cali