The Owosso times. (Owosso, Mich.) 1897-1926, 1916-11-10
The Pear PsylIa.

s"e Sos oybos
For the last two or three years an old
enemy Of the pear grower has been null
tiplying and playing havoc in the pear
orchards of the fruit belt, causing the
leaves and fruit to fall to the ground
long before their time, and If unchecked,
resulting finally In the death Of the
trees. The blsckened, smoky appear.
ance of the trees is due to the sooty fun
gus. which thrives'on honey dew secreted
by the insects. This sooty appearance
and the early falling of the leaves and
unripe fruit is usually sufficient to put
the pear grower on his guard.
Since the last serious invasion of this
pest we have progressed somewhat in
our methods of control. The pear psylls
passes the winter under the loose bark
Of the tree and in crevices wherever II
can hide, under rubbish and fallen
leaves. and in the nymph stage. on the
twigs in the bud axils. 81
The first step that should be taken in
fighting the pest is to scrape off the loose
bark. When the bark is soft 1t is easily
removed during the falFrains by means
Of an ordinary tree scrsper. This is done
in order that sthe spray which we use
later may be made to hit the insects,
since each insect must be hit to be killed.
The fallen leaves and rubbish on the
ground, both in the orchard and that
lying near by. should be raked up while
dry and during a cold period. for imme-
date destruction. preferably by fire.
Late blowing, after the wood is ripe,
would also dispose of much of the rub
bish.
Now comes the most important opera.
ton: Formerly we used kerosene emul.
sion. applying 1t at time when many
of the insects were In an immature con.
dition. Kerosene emulsion has fallen
from favor recently for obvious reasons,
and is being supplanted by the nicotine
sprays, these latter having advantages
over all other contact insecticides. At
present we find nothing better than MIC
otine sulphate, using it at the rate of
one pint of the 40 per cent nicotine sui.
phate to 100 gallons of water, adding
about FIVE pounds of soap to make the
spray spread better, and to make it wet
the pests more effectually.
Now to get the full value of the spray
1t must be applied at time when the
pests are exposed, but when it is cool
enough so that they will not travel at
all freely. Slingerland & Crosby, in
their manual, call attention to this mat.
ter, and advise that the spraying be
done during the warm days in Noyem.
Der and December, or In March and
early April At these times many of
the alternating adults leave the creyices
In the bark and crawl to the surface,
but do not become really active, nor do
they readily take flight. The applica.
ton should be made on days when there
Is no danger Of the liquid freezing on
the trees, and both sides of the tree
should be sprayed before proceeding to
the next tree, because the flies may
dodge around to the dry sides of the
branches and escape Slingerland &
Crosby recommend either kerosene emul.
sion. miscible oil. or else whale oil
soap, at the rate of one pound to six
gallons Of water, but they state that
these are not 30 satisfactory as the nico.
tine.
The scale sprays applied In the spring
help somewhat. but usually they are not
sufficient to control the pests without
the special spray just recommended.
Sprays put on after growth starts have
the disadvantage that 1t takes more
spraying material to cover a tree than IL
the work is done while the tree is dor.
mant Furthermore, IL one delays the
spraying until the nymphs acquire
wings, then one can hope for only par.
tial success at best. because the winged
forms will fly freely and escape being
hit. r. II. PETIT,
Entomologist. Experiment. Station.
East Lansing, Mich, Oct. 30, 1915.