Cottonwood report. [volume] (Cottonwood, Idaho) 1893-1901, 1896-03-13
is THE ONLY KNOWN REMEDY
The Amount of Water Required by
Crops is in the Aggregate Very
Large--HOg Market.

Professor ]. M. Aldrich, entomolo-
gist of the Idaho experiment station,
has just issued the following bulletin
regarding the pear leaf blister:
This little animal has become a SER
ious menace to the pear grower in
many parts of the state. 1t has the hab-
1t of secreting itself for the winter un-
der the little scales which cover the
leaf buds for the following year, es-
pecially those buds which are at or
near the tips of the twigs. 1t is there
fore easily overlooked. in fact impossi-
BILE to find without a glass. and so is
constantly beng introduced on new
stock into orchards that were previously
free from it, With a good pocket mag
n1fy1ng glass, the animal has the ap-
pearance of light yellow or whitish
minute wormlike object just large
enough so the general elongated shape
can be made out, and in warm room
1t can be seen to crawl about. Out of
doors, unless the weather is warm, it
remains stationary. After once finding
the animal with a glass, If it is on a
dark surface, it can be seen with the
naked eye, but only with difficulty, and
can not be distinguished from parti-
Gle of dust. The number in a single
bud may run up into the hundreds, but
is commonly between 10 and so.
AS soon as the buds open in the
spring, the little mite crawls upon the
unfolding leaf and buries itself in the
tissue, entering from the under sur
face. Inside the leaf it makes a little
cavity in which it lives and where eggs
are soon deposited. On the Matching of
these eggs the young mites usually
migrate to the newer leaves at the tip
of the branch or twig, where they make
their burrows and produce another
brood. There are several broods in
one season, so that the new leaves are
constantly suffering. Before the leaves
fall in autumn the mites migrate to
the next years buds to pass the win
ter.
The burrows of the mite are called
blisters. At first they are whitish in
color, but soon become red, and late
in the season they are usually brown.
Each is about the size of the head of
pin. There may be so many in leaf
that they touch each other over great
part of the surface, which is entirely
killed in that part, but always there
are parts of the leaf where the sep
arate round spots are distinct. This dis
tinguishes the work of the mite from
the pear blight, in which all or a part
of the leaf turns brown, but no small
distinct spots form.
These mites, unchecked, will usu-
ally ruin the healthiest tree in two or
three years. 1t sometimes happens that
large numbers of them are killed off in
the winter on account of unfavorable
weather, but this is only occasional. 1t
has not yet been ascertained whether
GOODNESS or warmth in the winter causes
them to die.
The only remedy at present known
is strong kerosene emulsion, and the
only time when it can be applied to
do any good is while the leaves are off
the tree in the winter. A thorough
treatment at this time is very effec-
tive, indeed, almost magical in it's re-
suits. The emulsion should contain
one-f1fth kerosene, and should be liber-
ally applied.
The common formula for kerosene
emulsion is as follows:
Heat one gallon of water to boiling
and dissolve therein a half pound of
soap mot the cheapest grade), and
while still boiling hot remove from the
nre ana ada TWO gallons OF kerosene.
Pass the mixture through spray pump
and direct the stream back into the
receptacle with as much force as posi-
BILE. This causes it to rapidly assume
the appearance of cream. Continue the
pumping five or ten minutes, or until
no kerosene separates at the top when
1t stands undisturbed for a moment.
When made, dilute with seven gallons
more of water, and it is ready for use
on the blister mite. For use on green
aphis, etc, it should be adulterated with
II to 20 gallons of water instead of
seven.
The expense of emulsion applied as
directed will amount, for materials,
to about five cents for a pear tree II to
Is feet high, with large top, and will
run down to a fraction Of a cent on
young trees only set year or two.