The Kootenai herald. [volume] (Kootenai, Idaho) 1891-1904, 1895-12-21
Insecticides and How to Prepare
Them.
INTERNAL OR FOOD P0lS0NS
Paris Green and London Purple Dis
IL ced All Other Substances for
ting Insects.

Every farmer and orchardist will find
the following list of insecticides valua-
BILE for reference. They are taken from
Bulletin No. II, just issued by the ex-
pertinent station at Pullman. prepared
by Professor G. " Piper:
There are two principal classes of in
secticides, namely, those that kill by
being swallowed with the food, internal
poisons, and those that kill through
contact, either by their irritating prop
critics, or by closing the breathing pores
of the insect or by both effects, external
poisons
Insecticides of the first class are to
be used only for biting insects, those
that bite and chew their food: those of
the second class mainly for sucking in
sects. those that take their food in a
liquid form only. In some cases, ex-
ternal insecticides can be used to good
advantage against biting insects.
Sucking insects obtain their food from
the juices of the plant by inserting their
sharp beaks into the tissues of the
plant. 1t is manifestly useless there
fore, to spray plants with an internal
insecticide for such insects, as the in
sects food, the sap or other juices of
the plant, is not reached at all by the
poison.
So likewise it is useless to spray with
an external poison for such biting in
sects as the borers simply because the
poison does not reach the part of the
plant on which they are feeding.
INTERNAL OR FOOD POISONS.
Two poisons, namely, Paris green and
London purple, have displaced all other
substances as the ordinary insecticides
for biting insects. They are Goth heavy
powders, the former briEht green in
color, the latter dull purple. In each
case the active poison is arsenic, of
which they both contain about so per
cent. The amount is less apt to vary
in Paris green than in London purple.
The former is the stronger insecticide
and acts more quickly; The latter re-
mains better suspended in water and
is cheaper. Paris green costs about 20
cents a pound in quantities; London
purple about half. that amount. White
arsenic which is sometimes recon-
mended should never be used. 1t is not
only dangerous to have around, but
burns foliage very readily when used.
There are two ways to use it.
The wet method-In this, the stand
ard method, the poison is applied in a
spray, using one pound of the poison to
$50 gallons of water for all plants ex-
cept the plum and the peach for these
two the strength should not exceed one
pound of the poison to $50 gallons of
water, otherwise the foliage will be
scalded
To prepare the spray the poison
should first be mixed into a fine paste
with a small amount of water, and an
equal amount of good lime added. The
mixture may then be washed through a
straner into the spray tank and the
proper amount of water added. With
London purple the lime must always be
used; it is desirable but not necessary
with the Paris green also.
The dry method-This consists in
busting the poison on the plants in q
dry form, diluting it first by thorough
ly mixing with flour, air-slalked lime
or dust. 1t is to be applied to the plants
preferably in the early morning. wher
wet with dew, by sitting through {
piece Of coarse cheeseclOth, or with {
powder gun. A convenient form o.
sitter is a joint of stovepipe. with tn,
cheesecloth tied over one end.
We recommend this method for cab
bage insects, for which one pound o
the poison is to be mixed with so pound.
of flour or dust. or a like proportion il
smaller amounts. The last application
should not be made later than ten day
before the cabbage is to be used and il
this application use in the proportion
of one pound of poison to 100 pounds o
flour. In applying use just enough 81
that it is plainly visible on the who'll
plant
For young plants of various kinds
attacked by flea beetles. use one poun'
of the poison to 80 pounds of flour, an,
use freely
EXTERNAL INSECTICIDES.
Kerosene emulsion is still the leading
insecticide of this class: Kerosene, tw
gallons; whale oil soap (or l ut. of sof
soap, one-half pound; water, one gal
Ion.
The soap is to be dissolved by boiling
in the water, which is then added, boil
ing hot away from the fire, to the kero
sene. The whole mixture is then vic
lently agitated by being pumped bac
on itself with a force pump through a
ordinary one-eighth-inch nozzle. Mos
forms of spray pumps answer this pun
pose admirably. After four or five mir
utes pumping, the mixture will have
thick creamy consistence, anc if we
made will stand indefinitely withou
free oil rising to the top.
Hard soap may be used instead Of tn
whale oil, but it is desirable to use
good quality, such as Ivory soap. TIL
best results, however. are obtained froi
using whale-oil soap.
Unless otherwise stated. the kerosen
emulsion is to be used dissolved in Wa
ter. in the proportion of one gallon
the emulsion to II gallons of water.