Oxford Democrat. [volume] (Paris, Me.) 1833-1933, 1920-12-28
AMONG THE FARMERS.
"srsrD THE rIow."
Posato Mosaic tl,rd to co..ro,


Potato Mosaic hurd to Control.
Cooperative work already conductsS
oy the Maine Agricultural Kxperimeu,
station and the Federal Bureau of Plant
Industry have shown the potato mosaic
IS important, is transmissible and IN car.
ried by plantlioe. Control measures so
far attempted have been only partially
sucoessful. The Station Council, which
includes representatives Of the state.
vide agricultural associations. have
authorised the entomologist to under.
take an Investigation In the hope that
potato mosaic can be circumysnted bv
an attack on the insects that carry this
disease. With this In view the station
plans study Of certain rose and other
sphids (plantlice) Of Aroostook County.
Now 1t may seem like q far cry from
rose sphids to potato mosaic. Once II
seemed . far cry from mosquitoes TO
malaria and yellow fever; or from house
n'es TO typhoid; or from red cedar and
ground juniper TO rusts Of apples; or
from currants and goose berries TO white
pine blister rust. Yet no one would
to-day to ight malaria or
yellow fever or typhoid or apple rusts
or white pine blister rust without refer
ence 10 mosquitoes, house flies, certain
conifsrs, and goossberry bushes.
From studies already made BY this
station We know that one Of the aphid-
carriers OF potato mosaic spends It's win.
ter egg stage on the rose OF which plant
the spring colonies develop and from
which it migrstes 10 potato and other
vegetation for the summer. While feed
ing in the potato field these aphids pass
from plants sick With mosaic to healthy
plants. carrying with them the disease
which they inOculate when they lab into
the tissue OF the plant with the sharp
beak through which they suck their
juicy repast. In the fall this species
returns to the rose.
The Inference that potato mosaic
might possibly be controlled BY eradi-
eating rose bushes from the vicinity of
potato fields is easily deducted from the
foregoing statements. The situation.
however, Is by no means 30 simple. For
It Is not one species of aphid only that
spends the summer on Maine potatoes
but several, and only one of these mi
CRATES to the rose. The habits, life
cycle, and other food plants for these
several species are not known. It will
be seen, therefore, that the prospect of
excluding aphid carriers of mosaic in
wolves study Of all the species at work
upon the potato in the hope that each
may have q vulnerable point in its life
history where it may be attacked and
routed.
Such hope is not without foundation.
The Maine Agricultural Experiment
Station has, through previous study of
aphiGs by the station entomologist,
established the fact Of migratory habits
of many species which deposit the over
egg upon one kind of vegets-
ton usually shrub or trse) upon which
the spring generations feed and from
which 1t dies to another sort OF vegets-
ton to pass the summer months.
Among such discoveries the following
few may be mentioned by way of Illus.
trstion: the migration OF the woolly
aphid of the apple from leaf cluster Of
elm tree to apple tree; the migration of
. closely related species from leaf roll
Of elm to June berry known widely in
Maine rs the "sugar plum"); the migra-
tion of the long g-beaked sphid from plum
TO thistle; the migration of the pond
plant sphid from plum to various water
plants; the migration of alder blight
aphid from maple to alder; migration of
cone gall aphid from black spruce to
white pine; and the aforementioned
Of the pink and green apbid
Of potato from rose to potato.
In each case mentioned, previous to
by the station eutomolo-
gist, the single aphid species concerned
with each migration had been consid-
cred two distinct species so different are
heir appearance, habits, or type of
work upon the two food plants. In
each case cited q knowledge Of the full
life cycle of the aphid has revealed q
unsupported method of con.
troll practical under certain conditions.
The indiscretion OF attem pting to grow
perfect plums in thistle patch, an orna-
mental maple tree next an untreatsd
alder swamp, ETC., ETC., becomes appar-
ent.
1t is, therefore, upon 4 foundation of
past successful Investigation with other
species of aphids, that the hope of
future potato aphid control 10 based-s
hope that is In no way a promise; for no
scientific inquiry can be undertaken
with pledge as to its outcome. The
work OF the station entomologist on the
potato mosaic situation will, Of course,
be confined strictly to the insect phases
of the work; the pathologists whose
past Investigations as to potato diseases
have advanced our knowledge of mosaic
and other troubles, will continue In
their work.
With plant pathologists and entomolo.
gist united against potato mosaic, shall
We not find fresh courage for the out
d. Woods.