Evening journal., 1907-07-18
SUCCESSFUL WAR
ON ARMY WORMS
Professor HOuehtOn Discusses
the Pest in interesting
Manner
PARIS GREEN AN ENEMY

Professor c. o. Houghton. entomol-
ogist OF the Delaware Experiment Sta
tion. has prepared an interesting
treatise on the Army Worm" The
best agent with which to destroy the
pest, he says, is a solution of arsenate
of lead or Paris green and water.
The army worms in this city are
rapidly being exterminated, as Health
officer Henry Lang has been fighting
them with a Paris green solution which
seems to be their deadiiest enemy. In
his treatise on the subject, Professor
Houghton says
For some time past there have been
occasional reports from various sec
tions of the State Of rather serious
injuries caused by the army worm"
II is the purpose Of this article to give
brief notes on the life history and
habits of this insect and some of the
methods by which it may be best con-
trolled.
Life History and Habits.
Unlike most insects, the "army
worm" may winter in any one Of three
stages,-as a larva, pupa or adult 1t
is probable, however, that the ma
iority pass the winter as pupae in the
ground.
The larva Ga true caterpillar. but
commonly called "worm') is too we'll
known TO require a detailed descrlp-
ton. When full-grown it measures
from one and one-half to two inches
in length. 1t is dark gray in color and
is striped with yellow; the head is
yellow, with fine, dark lines
The adult is a medium sized, night
flying moth, with the front wings OF a
reddish fawn color; there are numer-
Gus fine black specks scattered
about upon them, and near the mid
die Of each wing there is a small white
dot The hind wings are of a dull
gray color
The eggs are laid on grass and the
larvae begin to feed upon this as soon
as Matched. Says Dr. j. b. Smith:
In ordinary seasons, though the
larvae may be quite abundant. they
are little noticed and do no particular
injury; but sometimes, by a combina-
ton of circumstances. the number of
eggs deposited early becomes very
great and the resulting army of larvae
so large that they make havoc when
they hatch. In this stage they are
noticed i'm wheat where it is heaviest
and thence the caterpillars spread in
every direction. They soon become
full grown, go a short distance under
ground to change the mahogany
brown pupae about three -fourths of
an inch in length and shortly there
after the moths appear. They mate
at once and lay another batch of eggs,
from which we have about mid-sum-
mer second army much larger than
the first. These soon eat everything
on the ground first occupied by them,
and are then forced by hunger to be-
gin those marches which have given
them their common name, army
worm"
When full-grown these larvae enter
the ground for pupation and part OF
them may remain as pupae through
the winter. From other pupae the
adults may emerge which in turn de-
posit eggs for a third brood of cater
pillars which appears late in the sea-
son.
Remedies.
When a piece Of grass land is found
to be infested with these larvae i'm
large numbers. it is best to cut the
infested area at once and destroy the
crop, with the larvae, by means of
iire. or If the vegetation on which
the larvae are feeding can be thor
oughly covered with a poison spray,
this will be found an effective method
Of control For this purpose arsenate
Of lead or Paris green should be used.
the former at the rate Of / pound for
25 gallons Of water the latter at the
rate of ! pound to about $50 gallons.
In some cases il has been found
advisable 10 plow a narrow strip in
front of the advancing army" and
harrow and roll this hard; then to
crush the caterpilars by means of a
roller as they pass over this strip.
A strong kerosene emulsion is an
effective insecticide for these pests,
but this may seriously injure the
vegetation. If this is to be used, the
stock emulsion containing about 66
per cent. Of oil should be diluted
about four times with water.
G.. O. Houghton,
Entomologist to the Delaware Expert