Bulletin 151, Truck and Garden Insects


sweet corn that has not been attacked by at least one of these
caterpillars.
 Control.-The work of the first generation in the corn is
usually noticeable when the corn is about knee high. At this
stage it is not difficult to poison the caterpillars by spraying or
dusting some of the arsenic compounds into the infested buds.
The writer has dusted undiluted lead arsenate and zinc arsenite
powder into the buds without producing any harmful effects, but
it is safer and more economical to mix the poison with from 2
to 4 times its bulk of air-slacked or hydrated lime. The dusting
is best done in the early morning when the plants are wet with
dew. The agitation resulting from brushing against the stalks
will usually be sufficient to cause the dew to run down into the


bud, carrying the poison with i
can be applied by means of a
tin can punched full of holes.
On a large scale the well-
known bag-and-pole method
may be used, but the most
even distribution will be se-
cured by the use of a dusting
machine. It is important that
this early generation should
be destroyed, if possible. Not
only will the injury to the
buds be checked, but the


t. In a small garden the poison








 \.

 FIG. 80.-Corn ear-worm: Adult. One
 and a half times natural size. (Or-
 iginal.)


number of caterpillars in the following generation, which
works in the ears, will be lessened.
 When the silks appear on the young ears of corn they can
be dusted by means of the same apparatus. The caterpillars feed
on the exposed silks for only a few days before entering the ear,
where they are safe from insecticides, so it will be necessary
to repeat the dusting every three or four days. This is too
expensive for a crop of field corn, but on such a high-priced
crop as sweet corn it is worth while.
 In a small patch in the garden the worms can often be
removed from the tip of the ear before they have inflicted mate-
rial damage. In removing the worms it is not well, however,
to open the ears to such an extent as to expose the kernels, as
other animals such as birds, Carpophilus and other beetles, and
insects will then attack them. Woodpeckers and bluejays are
occasionally seen feeding on theworms and the ears of sweet corn.