The daily sentinel., 1912-08-17

croscope and made closer examina-
tion of the small white objects which
we found just beneath the surface
under the gum spots and was able to
definitely verify my opinion expressed
yesterday that the objects were the
empty shells OF an insect.
This morning have dug out of the
samples of injured peaches | brought
home total of 16 OF the egg shells
and have succeeded in making micro
scopic mounts of eight of the eggs
which Will be preserved permanently.
Under same cover ! am mailing you
couple of these shells mounted for
microscopical examination in balsam
on glass slide If you will hold
the. glass up to the light you can see
the shells with the naked eye and
with hand lens YOU can distinguish
the blunt, rounding end of the egg
laid deepest in the fruit and the
rather square. truncate end of the
egg which was found extending out
ward
With the higher power lens | could
easily make out the structure of the
shell showing fine reticulations and
at the eruncate end of the egg a
fringe of hook-like hairs. The eggs
an inch to one-sixteenth of an inch
in length and perhaps one-fourth or
one-third of this in thickness
OF course 1t is not usually safe to
determine the identity of an insect
from an examination of its egg only,
but | am sure the egg is that of an
hemipterous insect which feeds by
sucking the plant juice. instead of
eating the tissue. | should like TO
follow the injury through the spring
at the time the punctures are being
made to make sure of the Identity
OF the insect for | do not believe
that the adult insect is either depos-
iting its eggs or making food pune
lures in the peaches at this time. The
eggs have probably been laid when
the peaches were small and upon
Matching the larvae have left the
fruit to feed upon other vegetation.
As the peach grew the gum has ex-
uded through the ruptured skin ana
upon exposure to the air has harden
ed into the gummy threads and drops
attached to the peach Some feeding
punctures have probably been made
by the adult and perhaps by the new
ly hatch young and these punctures
have also yielded the gummy excre-
tions.
The egg shells found very closely
resemble those of the tarnished plant
bug uygus pratensis) but as there
are number of different species of
insects very closely related to this
bug and which have similar habits
would like to follow the observa-
tions further next spring to satisfy
myself finally on this point.
hardly think fhnt fhaan nnpr
lures are going to seriously affect the
carrying or keeping qualities of the
peaches. nor do | fear that the injury
is likely to become one of very great
Importance to the peach growers of
the Grand valley. Ii II should require
treatment II is certain that our ar
senical sprays will have no effect up
on its prevention
You will be interested in the dis
covery of the eggs in skin of the
peach Mt the gummy points since II
proves conclusively that the cause
is traceable to an insect and comes
from the outside instead of Internal
ly as some of the Grand valley grow
ers have contended. There are some
gummy excretions due to the peach
twig borer, but most Grand valley
growers know these injuries very
well.
l enclose a pamphlet containing an
article which l,prepared for an ento-
mological journal few years ago on
the egg laying habits of the tarnish-
ed plant bug in apples. and | have
seen a few cases of such injury in
apples about Grand Junction in the
past few years
Thanking you for your courtesies
shown me at the time of my inspec-
tion to look into the peach trouble.
am Very truly yours.
Z. +. TAYLOR.