Pike County press. (Milford, Pa.) 1895-1925, 1903-05-29
INSECT WARFARE
The Underlying Principles in De-
stroyiug Various Insects

stroyiug Various Insects
When a question is asked concern.
ing insects the answer that is given
depends upon certain principals that
are just as definitely established as
are mathematical formulae. These
principles depend upon the diff.
ferences in the structures and hab-
its of insects.
Any substance must belong to one
of three kingdoms Mineral, vege-
table or animal. Hence an insect is
an animal and we say it belongs to
the class or group of insecta. The
members of this class differ from
other animals in having six legs,
one pair of antennae, pair of COM
pound eyes, body divided in three
parts (head, thorax and abdomen)
each composed of rings or segnents,
breathing by a series OF air tubes
called trachea which permeate every
part Of the body These trachea do
not open at the nose and mouth, as
in higher animals, but along the
side at holes called spiracles.
There are two general ways in
which insects take food. One is by
chewing it as does the potato beetle,
cabbage worm, etc. land the other is
by sucking out juices, as do the
squash bugs, plant lice, scale insects,
and nearly all insects that are para
site on other animals. These two
methods of taking food are depend
ent upon two great types of the
structure of mouth parts. Those of
the first, or tee chewing insects,
have strong biting jaws that work
horizontally or from side to side
instead Of vertical or up and down
as in the higher animals. AS they
eat the tissues of the plant they also
eat any poison that would lie upon
it, hence biting insects can general
ly be killed by poisons whenever
they feed where poisons can be ap.
piled. Many biting insects, such as
those that feed in the soil on the
roots of plants and these that live
inside of plants, cannot be reached
by poisons and for them special
methods must be adapted according
to kind. The best general remedy
for such is to cut them out. A few
of the biting insects, such as the rose
bugs and blister beetles or sold
fashioned potato bugs" are poisoned
so slowly that special treatment
must be given them.
Their evidences can be seen or
they can be an ticipated and effective
poisons can be applied even when
the insects are not present. If rain
does not wash off the poison it will
remain and kill them when they
feed, as in sprayir g with arsenites
for the larvae of the cooling moth
before the eggs hatch. and in apply
ing poisons for certain biting insects
such as cut worms, that are conceal
ed by day. The chief poisons are
compounds of arsenic, called arse
mites.
The second group or suctorial
insects insert their sharp beaks
| beneath the surface of the plant
before they commence to suck out
the juices, hence they would not be
affected by poisons lying upon the
plants. They never eat away the
tissues of the plants, but by sucking
out juices, and often injecting a
poisonous saliva (as do the mosqui-
toes and most plant bugs) they effect
the injury. The only evidences of
their presence are the wlthered,
bhghted or shrunken leaves with
sometimes a deformity of leaf or
twig. Suctorial insects cannot be
killed by poisons that are to be
eaten, but substances that come into
contact with their bodies must be
used. Thus the applications must
made only when the insects are
present.
Questions on this and related sub
iects will be freely answered, either
through the columns Of this paper
or by private correspondence by IA.
A. Surface, Professor of Zoology,
State College, Pa.