The Elbert County tribune., 1907-12-19
Combined Insecticides for Plant Lice
and the CodIinq Moth.

Compineo insect'ctoes Tor Plant Lice
and the codIins Moth.
Professor c. P. Gillette. entomoIo-
gist Of the Colorado Agricultural Col
iege Experimental Station, contributes
the following:
On account OF the abundance OF the
green aphis and the woolly aphis in
many fruit growing sections, it is evil
dent that it would be a matter OF
economy to be able to apply together
insecticides that would destroy both
the plant lice and the codling moth or
apple worm.
Years ago certain entamologists, rec
ognizing the advantage of such a
spray, advised the combining of ker-
osene emulsion and a spray of Paris
greer, or London purple wherever il
was found necessary to destroy both
leaf feeding insects and plant lice
at the same time. / tried the combin-
alton of these insecticides until be-
came thoroughly satisfied that It is
not practical to use arsenical poisons
with a kerosene emulsion.
The oil in the kerosene emulsion
Is broken into extremely minute
globules causing 1t to be suspended
In water, and every solid body, az
the fine particles of Paris green or
London purple, serves as nucleus
about which the little globules collect
and then rise to the surface. which
soon results in the separation of
the oil from the mixture.
There are combined insecticides,
however that can be used with sue
cess and probably there is none bet
ter than spray composed of arsen-
ate of lead and either tobacco decoc-
ton or a strong, soapy mixture.
The orchardists upon the Western
Slope in Colorado have thoroughly
demonstrated that a tobacco prepare
ton known as Black Leaf Dip, used
In water In the proportion of about
one gallon Of the dip to sixty-fiye or
seventy gallons of water is a very
effectual remedy against the plant
lice of the orchard when thorough APP
plication is made. 1t has also been
thoroughly proven that arsenate of
lead is one of the best, if not the best,
arsenical poisons for the destruction
of the codling moth. AS the tobacco
preparation is not an emulsion and
as it does not combine in any way
with the arsenate of lead or act as an
antidite to this poison, these two in
secticides may be used together. In SO
doing it would be necessary to use
each poison strong enough to kill the
insects for which it is applied. BY
this / mean that the Black Leaf Dip
should be in the proportion Of about
one gallon to seventy gallons of the
mixture, and the arsenate of lead
should be in the proportion Of about
one POUND to twenty gallons OF the
entire mixture. AS the arsenate of
lead has no power to destroy plant
lice, neither has the tobacco prepara-
tion any appreciable effect in destroy
ing the codling moth lavae.
If winter or early spring applica
tions have been made in the orchard
for the destruction of the plant lice
and if these applications have been
successful it will not be necessary
to add the tobacco preparation at
the time of the first treatment of
the orchard for the codling moth
In fact, it is probable that il would
not be necessary to make the COM
bined spray mixture before the first
of June, or at the first spraying after
the plant lice are noticed to be pres
ent upon the trees. On the other
hand, If the winter or early spring
sprayings have not been attended to,
the combined spray could well be used
at the time for the first codling moth
treatment, or when the petals have
mostly fallen from the apple trees.
In case one prefers to use one of
the whale-oil or tree-soaps in place
of tobacco, they may be employed
without any deleterious effect upon
the arsenical poison, and neither will
the arsenical have any bad effect upon
the spray in its work of destroying the
plant lice. Most soaps used for the
destruction of plant lice may be used
in the proportion of one pound to eight
gallons of water. Then, in case soap
is used, 200-gallon tank should have
about ten pounds of arsenate of lead
and twenty-five pounds of soap for the
combined spray mixture.
1t will not do to depend upon using
a combined spray at all times. because
it will often be necessary to make an
APPLICATION for the codling moth when
1t is not necessary to make treatment
for the lice. And it will also be nee
essary occasionally to make application
for the destruction of the lice when
1t would be useless to add the arseni
cal poison.