Daily Kennebec journal. [microfilm reel] (Augusta, Me.) 1870-1975, 1917-08-18
The STALk-B0RER
At Work In Maine Corn
Remedial Measures

I
issued today from the Office of Director
Charles D. Woods of the Maine Agricul-
tural Experiment Station at the UNIVERSE
ty of Maine:
Extensive injuries to corn have recently
. been reported to the Maine Agricultural
Experiment Station. These have been ac-
companied by speciments of the Stalk
Borer (Papaipema nitela) which is some
times called the heart worm" on account
of the manner of the attack on corn.
Many Of the samples received We're at
work in the spindle. though the earlier
ones were farther down in the stalk be-
fore 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 pos
sible 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 fawn-
colored or mouse gray moth where the
young caterpillars can find access to
grass or weeds when they hatch the next
season The larvae work in the stems
of these plants while they are very small
but later, on gaining in size. they seek
larger plants with thick stems. Its feed
ing habits are recorded in an Illinois bull
letn:
1T 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 sim
gle 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 COM
PEELED 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 its area, the eggs are
laid in fall in grass or thick -stemmed
weeds in corn-felds, where these have
sprung up profusely after the corn has
been laid by. The blrrow 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 larva. Sometimes in leaving a
stalk it makes a new hole above that nv
which it entered. and it may in this wav
burrow in succession several differen,
stalks and several different kinds of
plants.
Besides the corn, wheat. and blue
grass already mentioned. it may infest
oats and timothy, various garden crons
including potatoes, tomatoes, rhuba rib.
and spnach-blackbe berry and rasnherrv
canes, the thick-stemn.el weeds. such as
ragweed, burdock and cock1ehur, COW
siderable variety of garden flowers. and
also the new growth Of the peach. cur
rant, grape, apple, willow, etc. Indeed
us 1000 pants are SO numerous as to in
dlcate a practical Indifference to kinds
the only necessary condition being a re,a.
lively thick stem. soft enough TO aIlow
II to enter and feed freely within. In the
small grains and larger grasses. Ike.oats
and timothy. it makes its presence mani
fest by killing or even cutting off Tho
stem within an encheathing leaf. TINS
causing the head and TIE whole n,art
above the injury to turn white and
presently 10 dry up It is one ONLY Of
several insects which produce this eer.
eral erect at this time, but rrs own in
jury may be at once distinguished bv tho
round hole which it leaves in the stor,
Of the infested plant"
The caterpillar, when full fed &c ,ho,,.
an inch and a quarter log. Tho nod,
color varies from purplish brown 70 Ii,b.
brown. Five white stripes run length
WISE 'hose along the sides being inter-
fuP'eo on the first four segments of the
ABDOMEN giving the caterpillar a broad.
dark band just behind its thoracic legs
When the larva is about ready to punat.
us whole appearance is more dingy
ana Uniform. so that this character
istic black band is nearly obliterated.
Inc head. the top of the neck, and the
anal shield are pale reddish yellow.
The insect pupates in its larval burrow
usually below its entrance hole. The
pupa Is smooth. light brown object
ABOUT three-fourths Of an inch In length
II Is from this pupal case that the brown
ish or grayish moth energies to Law eggs
for the next brood.
AS will be seen from this account cu.-
ting and destroying fby 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.