Dakota farmers' leader. (Canton, S.D.) 1890-19??, 1908-06-19
The Potato Plant Louise.

The plant louise seems to be the
pest of the American farmer in all
ATTITUDES and longitudes. Last spring
the papers were full of reports Of the
ravages Of the green bug, which is
simply plant louise affecting oats,
wheat, corn and other grain.
Farmers in the corn belt have long
been familiar with the corn root
louise, which is simply an aphis or
plant louise living upon the roots OF
corn. The potato growers in the
state of Maine have been complaining
for three successive years of the ray
ages of the potato plant louise.
The life history of these three vari-
cites Of plant lice, as well as Of count
less others which may be found on
many of our vines, are very similar.
The louse lives through the winter in
the egg form, matches out in the
spring, and the entire hatch is COM
posed of females which are called
stem mothers. These find their way
to their favorite plant and produce
young alive, not eggs but living
young. These are generally wingless,
but when plant food becomes scarce
the next generation is winged, so
that they can fly off to frcsher fields
and pastures new. In about eight or
ten days these aphides or lice become
mothers; 50 that one single stem
mother may in the course Of a season
be the ancestress of six million plant
lice When the potato vine becomes
short the potato plant louise seems to
select some new plant, grows several
generations on that, produces a
to the potato.
The Maine Experiment Station has
spent two or three years in inveSti-
eating and endeavoring to find some
method Of mbatting this pest, the
results being negative. Hence the
potato growers must depend alto
gether upon the natural enemies of
the louise, which are enumerated as
follows: O) Weather conditions
stand high among the controlling in
fuences, heavy continuous rains serv-
ing as check; (2) predaceous insects,
particularly two varieties Of lady
beetles and the larvae of syrphus
flies; parasitic insects: (3) fungus par
asiteS In other words, they are
about as helpless in dealing with this
pest as the wheat growers Of Texas
and Oklahoma we're in dealing with
the green bug last spring.
Fortunately the corn growers can,
if they will, keep the corn root louise
under control by the use Of methods
| which in themselves will give good
returns for their labor, namely, early
| plowing, more thorough cultivation
| of the ground, and better cultivation.
There is one law that seems to gov
ern in plant louise and other insect
] infestations, namely, that when any
large and continuous acreage for a
series of years, plant lice develop in
such enormous quantities as to rem
der it risky if not Improbable.
From this point of view these various
kinds of plant lice are benefit in
stead of an injury. 1t seems to be
the voice of nature protesting against
one crop farming.
One of the main crops of the state
of Maine, especially in Aroostook
county, where the infestation re-
ferred to occurred, is potatoes. The
main crop of Illinois and Iowa is
corn Here, again, the corn root
lousean corn root worm comes in
and says: "Go slower on corn"
The life history of these variou!
fosms Of aphides should form a very
fSasS8dE& subject for study in th'
[1ss a3n: @-
DR.. Eveieth went down to SiOul