The citizen. (Frederick City, Md.) 1895-1923, 1900-08-03
THE GREEN PEA LOUISE,
A New Insect Pest Which Threatens
the Canning Industry,

a New Insect Pest Which Threatens
the Canning Industry.
One of the most remarkable insect
invaSions on record for an entirely new
species is that of the green pea louise.
which last year appeared in countless
numbers and almost simultaneously
throughout the Atlantic coast plain,
the worst injury occurring that year
and also this in Maryland, Delaware.
Virginia and New Jersey.
In appearance the pea lice are much
like the common green fly of green
houses, or the wheat aphis, but are
much larger than either of these and
are entirely of light pea green color.
except the reddish eyes. Both winged
and wingless forms occur, the winged
forms being more common. In writing
OF this pest in Rural New Yorker Pro
fessor E. d. Sanderson says that late
In April of the present year crimson
clover in the first three states named
above was found to be infected with
this species. AS the clover approached
maturity the winged lice flew from it
to the adjoining peas and in some in
stances were carried considerable
distance by the wind, and it appears
that what was in all probability the
same species of aphid has been noticed
on crimson clover for at least six or
seven years. 1t seems almost certain
that the insect is, first of all, a clover
pest and very probable that originally
1t was pest of crimson clover
Professor SandersOn says it was most
interesting to observe the immunity of
early peas-mostly Alaska-when grow
ing Immediately adjoining a badly in
tested piece of crimson clover, while
the late peas were becoming badly in
fected. Almost entirely in southern
Delaware peas are grown in rows 90
to 30 inches apart. Even early peas
were found infected when broadcasted
or sown In eight inch drills There
seems to be no method of combating
the pea louise except when the peas are
in rows.
As to what the grower can do Pro
fessor SandersOn remarks: | had con
structed an attachment for a kerowa-
ter pump by which was enabled to
spray five rows of peas at once. The
rows were well sprayed and the larger
part of the lice We're hit. but 10 per
cent of kerosene evaporated so rapidly
in the hot sun as to kill hardly any,
and % per cent was so strong that it
seemed probable it would iniure the
vines though it killed the lice Tobacco
whale oil soap has been used with
somewhat better success by Maryland
growers. For the present all are agreed
that the only practicable means for
destroying the lice is that of brushing
by hand. This will be impossible upon
drilled peas, but fortunately for the
Delaware crop most of it is in rows.
Brushing has been and is being prac-
ticed in several places with considera-
Bile success. Boys are provided with
small pine branches, with which they
brush the vines, thus readily knocking
the larger part of the lice between the
rows. They are closely followed by
cultivator or harrow. which throws
many lice under the soil, others are so
thoroughly busted as to close their
breathing pores and thus kill them,
while others are literally roasted alive
by contact with the hot earth.
When the soil is damp or when the
vines are too large, the narrowing is
impracticable. In that case the same
end may be accomplished by drawing a
shallow pan similar to the "hOpperdoz-
ers' used in the west for grasshoppers
between the rows and brushing the lice
into it.
Very probably if only early varieties
are grown for a year or two Mother
Nature will take care of the pea louise
/. e., It's parasites will increase in such
numbers as to keep it in bounds, and
late varieties may again be planted.