St. Landry democrat. (Opelousas, La.) 1878-1894, 1885-01-17
The Army Worm.


even now one of the debated questions
of entomology, and needs more close
observation before all will agree as to
whether it is single or double brooded
in the Northern States. Also it's man.
ner of passing the winter, the causes
necessary to its occasional great devel-
opment, and the reason why it marches
every now and then. For it is usually
found with US as a simple cut worm,
unnoticed, feeding at night and hiding
at the roots of the grass during the day-
time. It was formerly claimed that ST.
Louis was about as far North as it was
found to be double brood, but latterlY
even the latitude of Iowa is believed bv
many to possess two broods year. We
recently visited field in the southern
part of Muscatine County where week
or ten days ago all the heads of timothy
in parts of the field were alive with the
army worms, and although we searched
carefully we could not find a single
worm, only some of the cast-off mott
ings that were LETT ctineing to portion
of the heads. The worms had descended
into the ground where they have changed
into pupae.
Now, if there is but one brood q year
they will not emerge from their subter-
ranean home until the next spring, but
if there be two broods, in about six
weeks the army worms will again be
at work, very likely, however, in small
numbers, for they have great host of
insect enemies, prominent among which
are the red-tailed tachina fly, Memo
rGeG CucGntaI) the yellow tailed tachina
fly, (EG0rtstG ElGUtcu'etlg) J, and num-
Der of beetles and small ichneumon
flies. These enemies usually keep the
worms in check, but frequently they are
baffied in their good work.
The worm when full-grown is from
an inch and quarter to an inch and q
half long. It is striped lengthwise with
alternating stripes of dirty white and q
greenish brown cast. An observer,
who has been watching the worm feed,
describes their method to us as fol-
lows:
They creep up the spears of timothy,
sometimes pausing half way up the head
and often reaching the very top. Then
they bend the head over into a curve,
the worm occupying the concave side
of the curve, and commence feeding,
retreating backward until the head is
nearly if not entirely destroyed This
statement seemed to us to be fully con-
frmed by the aspect of the timothy
heads, and the moltings of the worms
left as mementoes of their visit. The
blades of the hay also had ragged ap-
pearance where their egdes had been
eaten, while the clover that grew
among the hay was untouched. just
over the line in Louisa County is another
field, two miles distant from the first,
where over four acres of timothy were
entirely destroyed.
From specimens reared in captivity,
the age of the worm has been estimated
to be from fifteen to thirty days. Then
they descend into the ground a few
inches, where they spin no cocoons, but
in simple little earthen cells change into
dark pup@, averaging
two-thirds of an inch in length. After
seventeen days pass away, they make
their next appearance, this time in the
role Of pretty faWn-colored moths, ex-
panding an inch and a half, with the
principal marking simple dot near the
center of each front wing. From sixteen
to seventeen days is the average life of
the moth, during which the eggs are
between the folded edges of a
blade of grass near the base, and are
covered with white, glistening fluid.
Years ago, DIR. Fitch, who was one of
the earliest observers of the insect, adj
vaneed the theory that the army worm
years were unusually wet, preceded by
unusually dry, summers. This theory,
like all others, has its friends as well as
foes, the latter arising from the fact
that occasional local exceptions do occur,
but the greater weight of testimony is in
it's favor, consequently it is generally
accepted. The summer of 1881, in this
vicinity, was very dry, while this season
is exactly the reverse.
It is a commonly known fact that the
army worm may be kept out of a field
by surrounding it with a ditch, from
eight to twelve inches deep, taking care
the sides toward the field shall be per-
pendicular The worms fall into it and
can not climb the perpendicular sides.
They can now be killed in various ways.
Some farmers drag log through the
ditch and thus crush them. Others have
holes in the bottom of the ditch about a
foot deeper, and from sixteen to twenty
feet apart, into which the worm drops
while attempting to escape. They are
killed by covering them with straw and
burning it, or by burying with dirt and
pressing it down. Ii q field of hay is
already infested so as to be destroyed,
the best thing to be done ordinarily is
to pillow it under while the worms are
young and plant some other crop. For.
for the farmers, two army.
vorm years in one locality rarely, if ev-
u, follow each other.-ALtce b. Walton,
% loeCG State Register.