The Republican journal., 1917-08-16
The Stalk-Borer.

| ly been reported to the Maine AgricuItur-
al Experiment Station. These have been
accompanied by specimens of the Stalk
Borer which is sometimes called the
heart worm" on account of the manner
OF the attack on corn. Many of the
samples received were at work in the
spindle, though the earlier ones were
farther down in the stalk before the
spindle pushed out.
The only direct method of control is
the removal and destruction of infested
stalks as soon as the presence of the pest
is discovered. This, of course, will not
save the corn stalk of 1917 but it will re-
duce the numbers of the insect and prove
one useful preventive for 1918.
There are other control measures posi-
BILE with reference to next year which
will be made evident by an acquaintance
with the life history of the Stalk-Borer
as outlined in the following account.
The eggs are laid in the fall by faun-
colored or mouse gray moth where the
weeds when they hatch the next season.
The larvae work in the stems of these
plants while they are very small, but later
they seek larger plants with thick stems.
Its feeding habits are recorded in an ILL
nois bulletin:
ut is most noticeable in early spring in
bluegrass, by roadsides. or around the
borders of a field, its presence there being
betrayed by the whitening of single heads
of the grass while all the rest of the plant
is green. At this time it is of small size,
and finds sufficient food within the grass
stem; but later it is compelled to resort
to thicker-stemmed plants, and it is at
this time that it may appear in fields of
corn.
Going in usually from outside of the
field, its injury is, as rule, almost
wholly confined to the outer rows. 1t is
probable that where the injury is not
limited to the margins of the field, but is
general throughout it's area, the eggs are
laid in the fall in grass or thick-stemmed
weeds in corn-fields, where these have
sprung up profusely. The burrow which
the stalk-borer makes within the stem
runs upwards from the entrance opening,
and of course varies in size with the
growth of the Iarva. Sometimes in leav-
ing stalk it makes new hole above
that by which it entered, and it may in
this way Durrow in succession several
different stalks and several different kinds
of plants
Besides the corn, wheat, and blue
grass already mentioned, it may infest
oats and timothy, various garden crops
including potatoes, tomatoes, rhubarb,
and Standardization and raspberry
canes, the thick-stemmed weeds, such as
ragweed, burdock, and cocklebur-a con-
siderable variety of garden flowers, and
also the new growth of the peach, cur
rant, grape, apple, willow, etc. Indeed,
it's food plants are SO numerous as to indi-
cate practical Indifference to kinds, the
only necessary condition being relative
ly thick stem, soft enough to allow it to
enter and feed freely within. In the
small grains and larger grasses, like oats
and timothy, it makes it's presence mani
fest by killing or even cutting off the
stem within an ensheathing leaf, thus
causing the head and the whole plant
above the injury to turn white and pres
emily to dry up. 1t is one only of several
insects which produce this general effect
at this time, but its own injury may be
at once distinguished by the round hole
which it leaves in the stem of the infest-
ed plant"
AS will be seen from this account, cut
ting and destroying (by feeding or other
wise) the infested stalks one season will |
reduce the number of these insects be-
fore they develop to lay eggs for the
next. Clean culture by fall and spring
blowing to destroy the vegetation near
which the eggs are deposited will also
seem logical. Also if grass land adjoin-
ing corn or potato fields or garden plots |
shows in spring the work of the young
larvae, it might be worth while to NOW
the infested grass and feed it before the
caterpillars could escape to enter the
corn. CHAS. D. WOODS, Director.