Walter Collins O'Kane.

Injurious insects : how to recognize and control them online

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but the use of large iron kettles is permissible, provided the material
is stirred constantly and vigorously during the entire time it is cooking.
Place in the boiler 20 pounds of stone lime. Add a few gallons of
hot water to start the lime to slaking, and then gradually add 15 pounds
of flowers of sulphur, stirring constantly. Add 12 gallons of hot water,
and boil hard for an hour. Dilute with more hot water until there are
50 gallons of the mixture. Strain carefully, using preferalily a brass
wire strainer with twenty meshes to the inch. Apply the solution
while still hot.

Kerosene Emulsion

Hard soap h pound

Hot water (^soft) 1 gallon

Kerosene (coal oil") 2 gallons

Dilute as ihreeted.

Kerosene emulsion is a valuable insecticide, especially for destroying
hibernating insects in rubliish, and. when further diluted, for killing
plant lice, and other similar insects. The ingredients are kerosene
(coal oiD. soap, and water. By means of the soap the oU is broken tip
into extremely fine particles, or, in other words, is " emulsified," so
that in effect it may be applied greatly cUluted, and its kiUing power on
insects secio'ed without injuring plant tissues.

To prepare, sha^"e up k pound of launch-y soap in 1 gallon of soft



74 INSECTICIDES FOR SUCKING INSECTS

■water. Have the -neater boiling hot. A.s soon as the soap is all dis-
solved, remove the solution from the fire and add 2 gallons of kero-
sene. At once agitate the material violently. This is best accom-
phshed by the use of a bucket pump, turning the nozzle back into the
bucket, so that the material is constantly passed through the pvunp.
In a few minutes a smooth, creamy emulsion is formed, without any
free oil. This vnR become thicker as it cools, but if it is properly made,
no oil ■n-ill separate out. This is the stock material, and T\-ill keep well,
if sealed from air.

For use on trees or shrubs that are dormant it is customarj' to dilute
the stock emulsion with 5 to 7 parts of water. On trees or plants in
leaf dilute •«-ith 10 to 15 parts of water, depending on the t}"pe of in-
sect and the kind of foKage. Soft-bodied insects such as plant hce are
easily killed by a dilution containing only 5 or 6 per cent of oil.

To get exact dilutions use the following table :
For i'^c strength add lof gallons of water to 1 gallon of stock solution-
For 0% strength add 12| gallons of water to 1 gallon of stock solution.
For 7% strength add 8^ gallons of water to 1 gallon of stock solution.
For 10% strength add of gallons of water to 1 gallon of stock solution.
For 12% strength add 4j gallons of water to 1 gallon of stock solution.
For 15% strength add 3i- gallons of water to 1 gallon of stock solution.
For 1S% strength add 2f gallons of water to 1 gaUon of stock solution.
For 20% strength add 2^ gallons of water to 1 gallon of stock solution.
For 25% strength add If gallons of water to 1 gallon of stock solution.

Oil sprays are best applied on a sunny day when the wind is blowing,
since surplus oil will then evaporate more quickly and there will be less
danger of injuring the plant.

Crude oils are emulsified in the same way as kerosene. For certain
insects, as indicated later, tliis spray is effective and desirable.

Linseed Oil Emulsion

Hard soap 1 pound

Hot water (soft) 1 gallon

Linseed oil (raw) ..... 2 gallons
Dilute as directed.



TOBACCO EXTBACT 75

The manner of making linseed oil emulsion is similar to that of
making kerosene emulsion. The material has a special use in fight-
ing oyster shell scale.

To make the stock emulsion take 1 pound of soap, shave up fine,
and dissolve in 1 gallon of boiling soft water. When the soap is
all dissolved, rcmo^-e the solution from the fire and add at once 2
gallons of raw linseed oil. Churn the mixture violently by pumping
it back on itself with a luicket pump, .\fter a few minutes, a yellowish,
smooth, creamy emulsion will be formed. Xo oil should separate out,
if the stock is properly prepared.

To prepare for use, take 1 gallon of the stock and dilute with
9 gallons of soft water. Tliis is for use on trees not yet in leaf.
For oyster shell scale it is best applied just before the buds swell in the
spring.

Commercial Tobacco Extract

Higlily concentrated extracts of tobacco are now on the market,
and constitute a ^•aluable class of contact insecticides. The>- are
dark-colored hquids, and arc prepared for use by diluting with water,
according to the degree of concentration of the brand purchased and
the kind of insect concerned. It is advantageous to add soap to the
solution, in order to make it spread more readily and prevent it from
collecting in globules. I'se 1 pound of soap to 50 gallons of the
diluted spray.

Rather strong dilutions of commercial tobacco ex-tract have been
found of possible value as winter spra>-s to kill the over\A-intering eggs
of certam plant lice on the bark or twigs of dormant trees.

Weaker dilutions are standard remedies for fighting various soft-
bodied sucking insects, such as plant lice, thrips, and the like. These
dilutions are applied with perfect safety to trees in leaf.

Similar dilutions are used as dips for sheep or other domestic ani-
mals, to kiU mites and lice.

•• Black Leaf 40," containing 40 per cent nicotine sulphate, is used
for winter spraying, as noted abo^'e. at dilutions ranging from 1 part
to 300 of water down to 1 part to 600. For use in summer the dilu-



76 lySECTICIBES FOR SUCKING IXSECTS

tions range from 1 part to 500 in the case of resistant insects down
to 1 part to 1000 in the case of tender plant lice. The dilutions for
killin g lice and mites on animals are similar to the last named. The
strength of 1 to 500 should be used only as a wash and not as a dip,
when treating pests on animals.

" Sulphate of Xicotine " is a preparation of similar strength, and
the dilutions are the same.

Liquid " Xico-Fume " contains 40 per cent free nicotine, but the
dilutions and manner of use are similar to the above.

" Black Leaf E.vtract " contains a much lower percentage of nico-
tine, and less water is added to it than to the others named.

Home-made Tobacco Extract
If tobacco stems or tobacco dust are available, an extract may be
made at home. To prepare, pack the stems in a pail or kettle and
cover with water. Allow to stand over night. Or. boil 1 poimd of
dust or stems in 1 gallon of water. An hom-'s boiling is stifEcient.
Dilute the extract with 1 to 2 parts of water. This material
may safely be applied to plants in leaf and is effective against plant
lice. Add soap at the rate of 1 pound to 50 gallons of spray. It is
not ad^'isable to employ this as a winter spray to kill the eggs of plant
lice because the percentage of nicotine present may not be sufficient.

Insect Powder

Insect powder 1 ounce

Water 2 gallons

This is the material variously kno'RTi as pjTethruni. buhach, or
Persian insect powder. It consists of the finely ground flower buds
of a plant. The active principle is volatile ; hence the material rapidly
loses its strength on expcsure to air. It must be fresh, or must have
been kept in a closed receptacle, to be effective.

Coromonly it is used dry. Small powder guns are obtainable for
apphdng it.

To use it as a spray, mix 1 ounce in 2 gallons of water. If it is



SOAP SOLUTION 11

desired to use it in larger quantities, a con\-enient metliod is to steep
1 pound in 1 gallon of alcohol, then dilute with 40 gallons of water.
This material is not poisonous to man or the higher animals.

Soap Solution

Hard soap 1 poimd

A^ ater 5 gallons

A simple solution of soap and water is effective against plant lice
and similar sucking insects, and is especially useful for treating insects
infesting house plants, where it is not desirable to use other and less
pleasant materials.

Ordinary laundi'v soap may be used. Dissoh'e 1 pound of soap
in 5 gallons of water. Tliis solution will not injure plants in leaf.

Whale-oil soap may be used instead of laundi-y soap. The potash
soap is best. It should contain not over 30 per cent water. One
pound in 4 or ,5 gaUons of water is the proper strength for plants
in leaf.

A solution of whale-oil soap and water is sometimes used for San
Jose scale, applying it to trees in winter, wliile they are dormant.
For such use, take 2 pounds of the soap to 1 gallon of hot water.
This material is not as effective against scale as hme-sulphur solution,
and the cost is greater.

Carbolic Acid Emulsion

Hard soap 1 pound

Hot water l^soft) * gaUon

Carbolic acid (.crude) 1 pint

Dilute as dii-ected.

This is one of the remedies occasionally reeonmiended for kilUng
root maggots. These maggots are not properly sucking insects, but
because of the conditions under which they are fomid. the use of a
contact insecticide is sometimes recommended.



78 IXSECTICIDES FOE SCCKiyG IXSECTS

Carbolic acid emulsion is prepared in the same manner as kerosene
emulsion. Dissolve 1 pound of hard soap in \ gallon of boiling
water. Then add 1 pint of crude carbolic acid, and at once chum the
mixture by pumping it back on itself with a bucket pump until a
smooth emulsion is formed.

This is the stock material. To prepare for use dilute at the rate of
1 part of the stock emulsion to 50 parts of water.



CHAPTER XVI
Repellents

OccASioxALLY somc cliemical is found to lie of service in driving away
insects at work on a plant. INIauy remedies of this nature are pro-
posed from time to time, but in most cases further tests prove that
they are without real vahie.

Dnj-slal:cd U)uc is of ser\-icc in driving away certain pests, such as
the striped cucumber beetle. To prepare, phice fresh lump lime in a
metal vessel and add a smaO amount of hot water. The lime will
slake to an extremely fine powder. This is dusted on the insects.
If desired, flowers of sulphur may be added to the slaked lime.

Tobacco dust is reasonably effective as a repellent. It must be
fresh, and is dusted directly on the insects ; or when used as a pre-
ventive of attack by root maggots, the dust is heaped up around
the stem of each plant.

Xaphthalinc. or " moth balls," is of moderate value as a repellent
for such insects as the common clothes moths, or for some of the
pests that iiifest dried animal products. This material is not, how-
ever, a complete protection. It should be noted, further, that if
moths have already laid their eggs on garments, and the latter are
afterwards packed away with naphthaline, no benefit whatever will
be secured. The substance is a repellent solely for the adult moth,
and not for the larva, which does the real damage.

Protective Wash for Trunks of Trees

Dissolve 2 quarts of strong soft soap in a bucket of water. One
pound of hard soap may be used instead of the soft soap. Add i
pint of crude carbolic acid and 2 ounces of Paris green. Then add
lime, or clay, or both, so as to make a thick paste.

Paint this on the trunks or limbs of trees as a deterrent for borers.
It will not give entire protection, but will help to ward off attack.

79



CH.\PTER XMI

FuillGANTS

In general, fumigation is available for killing insects only when the
plants or substances treated are in an inclosed space. This is for the
reason that the various gases which are the active killing agents in
any fumigation must be confined to be effective.

Fumigation is commonly used in greenhouses, in the treatment of
pests infesting stored or manufacttu-ed products, and in the treatment
of nurser\- stock suspected of infestation with San Jose scale. The
methods emploj'ed and the strengths of material used vary with these
different classes of work. The general manner of using the chemicals,
and the principles involved, are similar.

Carbon Bisulphide

Carbon bisulphide . . 1 pound to each 100 cubic feet

This is the material ordinarily used for killin g pests of stored and
manufactured products, except in grain elevators where the risk of
accidental fire is considered too great. It is a clear, hea'vy hquid,
with a strong and dbagreeable odor. On exposure to air, it evapo-
rates rapidly, gi^ijig off a gas that is hea-vier than air, and therefore
diffuses down rather than up.

.Allow 1 pound of carbon bisulphide for each 100 cubic feet of
space in the fumigating chamber. Or, if grain is being fumigated,
allow 1 pound of the liquid to each 100 bushels of grain. In small
quantities this is about equivalent to 2 drams to the bushel.

This is the dosage at ordinan.- temperatures of 60' to 70° Fahren-
heit. At mucli lower temperatiu-es a header dose will be required,

80



CAEBOy^ TETRACHLORIDE 81

and at higher temperatures one half to tlu-ee fourtlis of the abo\-e
will suffice.

Place the material to be treated in a box, Ixirrel, or bin that can
be made at least fairly air tight. Pour out the carbon bisulphide in
one or more shallow dishes, and place on top of the nraterials. Put
on the co^■er at once, and leave for twenty-four hours. Blaidcets or
can\-as thrown over the top of the box will assist in retaining the
fumes. Do not allow any fur, or ci>cn a lighted cigar, angwhcrc }iear
at the time of fumigating or for a period after, until the fumes ha\-e
disappeared.

I'se reasonable care not to breathe the fumes too much or too long
at a time, as they will be apt to cause headache or illness. No in-
convenience should be experienced if ordinary care is exercised.

If large amounts of grain are being fumigated, it is best to intro-
duce some of the hquid to the middle layer of the heap instead of
putting aU on top. To do this, tit a round stick loosely in a section of
small iron pipe. Leaving the stick in the pipe, shove it down through
the grain. Then withdraw the stick, and pour the desired amount
of the carbon bisulphide down the pipe. The stick merely serves to
keep the grain from filling the pipe when it is sho^-ed down into the
heap. After being fumigated, the grain should be sho\'eled o^■er, so
as to help remove the gas remaining in it.

Carbon Tetrachloride

Carbon tetrachloride . . 2 pounds to each 100 cubic feet

A substitute for cai-bou bisulphide is found in carbon tetrachloride.
It has the ad\'antage of being nonexplosi^-e, and therefore may be
preferred in fumigating bins in a house or barn, or wherever there is
possible danger of fu'e. It is not as active as carbon bisulphide, and
will not kill insects as readily.

The proper strength to use is 2 pounds of carbon tetrachloride for
each 100 cubic feet of space or each 100 bushels of grain. In small
quantities use -1 drams to each cubic foot or each bushel of grain.



82 FUillGANTS



Sulphtir

Under some conditions a satisfacton.- fumigation may be had by
burning sulphur at the rate of 2 potmds to 1000 cubic feet. It should
be noted that the fumes are harmful to vegetation, that they will
bleach fabrics, and that they wiU destroy the germinating power of
seeds. As a means of killing bedbugs in empty rooms the treatment
is excellent.

Place the sulphtir in a fire-proof vessel, and this in turn within a
larger vessel, and ignite. Keep the place closed for 24 hours.

Hydrocyanic Acid Gas

The most active fumigating agent in use is hydrocyanic acid gas,
made by combining water, sulphtiric acid, and potassium cyanide.
This gas is a deadly poison to man as weU as insects, and its use should
not be attempted tmless careful precautions are taken, or the opera-
tor has had experience. It should never be used for fumigating any
part of an inhabited house, unless the entire premises can be vacated
for two or three days trntU the structure is thoroughy aired.

For fumigating nursery stock, the materials are used in the propor-
tion of 1 ounce of 9S per cent potassium cyanide. 2 ounces of com-
mercial sulphtiric acid, and 4 ounces of water for each 100 cubic
feet of space in the fumigating chamber. The chamber is kept closed
for 40 minutes. To generate the gas. have ready an earthen crock
of generous size. Poiu^ the necessan.- amount of water into the crock,
and slowly add the sulphuric acid, stirring the imxture, Xever re-
verse tills order and pour the water into the acid. Considerable heat
will be generated. Place the proper aniotmt of potassium cyanide in
a paper bag, or tie up loosely in paper, drop the package into the
crock, and at once leave the room, closing it up air tight. A con-
venient way of adding the cyanide is to suspend the bag over the
crock with a string, the other end of which is led through a small
hole in the fumigating chamber, so that the operator can retire first
and seal the door, and then lower the bag of cvanide into the acid.



SYDROCYAyiC ACID GAS 83

7;i fumigating a house, or a part of a house, the materials are eom-
bmed m the same mamier as above, but the proportions to use are
1 ounce of e>'anide, 1 ounce of sulphui-ie acid, and 3 ounces of
water to each 100 cubic feet. All cracks should be sealed or stopped
up. Gummed paper is useful for this purpose. After the fumigation
is complete, the house must be aired out Isy opening the T\'indows
from the outside. Fumigation of dwellings ought never to be
attempted unless one thoroughly understands the process and the
necessary precautions.

In greenhouses the amount of material to use camiot definitely be
specified in advance, and ought always to be ascertained by careful
preliminary trial. Different plants will withstand varying amounts
of the fumigant, and much depends on the tightness of the house.

It is best to begin with a dose of j to j ounce of cyanide to the thou-
sand cubic feet, continuing the treatment for about 2 hours, at once
airing the house and obser-^-ing results. If the insects are not all
killed, and the plants are uninjm-ed, the dose may be made a little
heavier.

Fumigation in greenhouses must aways be done at night, and the
leaf surfaces must be dry. The house may be aired out late the same
night or early the next morning, before the sun is hot.

Greenliousc fumigation is of special value against mealy bugs,
wliite fly, and violet aphis, because other possible treatments are in-
jurious to the plants or ineffective. It is not successful against scale
insects or red spider.

^^'hen greenhouses are cleared of plants between crops, they should
be thoroughly fumigated, using the cyanide at the rate of 5 to S ounces
to the thousand cubic feet and continuing the treatment over night.
Valuable protection will thus be secured for the succeeding crop.

Fumigation with Tobacco

For the control of most plant lice in greenhouses, fmnigation with
tobacco is a common method. This cannot be employed in houses
containing ^^olets, since the fumes will spot the leaves.



84 FVillGAXTS

The usual method is to burn stems or dust, or to vaporize liquid
extracts of tobacco, or to make use of a specially prepared ptmk now
on sale in stores. The last is usually the mo.st satisfactory method.

It is desirable in tobacco fumigation to generate the smudge near
the level of the floor, because it rises rather rapidly, and if generated
at the height of the benches, much of the strength of the fumigant will
be concentrated near the roof.



CHAPTER XVIII

FUXGICIDES COMBINED WITH PoiSONS

^Materials that are used for the control of plant diseases, such as
scab, mildew, and the hke, are called fungicides, as contrasted with
materials used for the destruction of insects, called insecticides. Fungi-
cides are not intended for the control of insect pests, and for the most
part hare no I'aliic whakivr in inject warfare.

However, one of the materials commonly used for plant diseases,
Bordeaux mixttu'e, has also some effect in driving away certain insects
from plants, or at least is distasteful to them. A second fungicide,
lime sulphur, as prepared for use in summer on trees in leaf, also has
some value as a mild contact insecticide, of considerable ethciency
against such soft-bodied sucking insects as plant lice.

In addition, it is conunon practice to use either of these materials
with a poison, such as arsenate of lead, added to it, as a combined
insecticide and fiutgicide, instead of applying the two sprays sepa-
rately. Directions for their preparation and use, therefore, seem
proper at this point.

Bordeaux Mixture

Copper sulphate 4 pounds

Lump lime 4 pounds

Water 50 gallons

Bordeaux mixture is a combination of copper sulphate, often known
as " blue vitriol " or " bluestone." with lime and water. It may be
bought in paste form, ready to dihite with water and apply ; or it
may easily be made at home.

To make Bordeaux mixture, place 25 gallons of water in a liarrel,
and suspend iii it, just below the surface, a cloth bag containing 4

So



86 FUNGICIDES COMBINED WITH POISONS

pounds of copper sulphate. Allow the copper sulphate completely to
dissolve. K it is desired to hurn- this part of the process, the sul-
phate may be dissolved iu hot water, using about 2 gallons and
stirring well, and this may then be poured into the barrel and the
latter filled up to 25 gallons. In another barrel slake 4 pounds of
lump lime, adding more water and stirring well as the hme dissolves,
until there are 25 gallons in the barrel. Then combine the sulphate
solution and the limewater by dipping alternately from each into the
spray tank. Or, the two may be poured slowly at the same time into
the spray tank. It is essential that the mixture be thoroughly strained
as it goes into the sprayer.

On some plants the above formiila for Bordeaux mixture is too
strong, and should be altered to the following : copper sulphate. 2
pounds ; lump lime. 2 pounds ; water, 50 gallons. The method of mak-
ing is the same.

Bordeaux mixture must be used as soon as prepared. If allowed to
stand, it changes in composition. More hme may be added, and the
material thus made use of, but this procedure is not recommended.

'Where this material is used in large amounts it is convenient to
prepare separate stocks of copper sulphate solution and hme '' putty."
Kept separate, theynill not deteriorate. Dissolve the copper sulphate
in water at the rate of 1 pound of the sulphate to 1 gallon of
water. One gallon of this concentrated solution will then equal 1
pound of the sulphate. To prepare hme putty, place a known weight
of lump lime in a fiat trough and add just enough water to slake it.
When it is all slaked, see that it is spread out evenly and cover with an
inch or so of clear water, to exclude the air. It will be easy to figure
out the number of square inches of putty to remove in order to have
the equi\-alent of the desired weight of limip hme. Do not make the
mistake of weighing out this putty and considering that a given weight
is the equal of the same weight of lump lime.

Arsenate of lead may be combined T\-ith diluted Bordeaux mixture ;
but the better plan is to add it to the limewater before the final mixing.
The poison should first be well mixed with water, so as to make a
thin paste, in order that all of it may find its way into the final mix-



SUMMER STUEyOTH LIME SCLPHZ-Ji 87

ture. If this is done, allowance must be made for the volume of the
arsenate of lead solution when filling up the barrel of limewater to
the requisite 25 gallons.

A ready prepared Bordeaux paste containing arsenate of lead is on
sale in stores.

Summer Strength Lime Sulphur

Smmiier strength lime sulphur is now coming into use as a fungi-
cide for the control of certain diseases. While this is similar, chemi-
cally, to the lime-sulphur wash useci as a winter spray for scale insects.
it is much weaker. It is prepared by proper dilution of the com-
mercial concentrated solutions, or by a so-called " seh-boiled " method,
in which the chemical composition is somewhat different. The proper
dilutions of lime-sulphur concentrate for summer spra>'ing of apples,
making use of the Baiuu^ hydrometer as a measure of strength, are as
follows :

Ix Degrees B.vrMi; Number of Gallon's

E£.U)UXO OF HrDHOilETEK OF W.VTER TO OnE G AL-

LOX OF COXCEXTR.ATE

35 45

34 43*

33 41 i

32 40

31 37*

30 36i

29 34}

28 321

27 31

26 29*

25 27|

24 26

23 24}

0t2 22|

21 211

20 m

19 ISi

18 1"

17 1<5

16 15

15 14

14 r2|



88 FrXGICILiES COilBiyEU WITH poisoys

Remember that these are the dilutions for summer strength lime
sulphur to be used on apple trees in leaf, and not for the winter wash,
which is much stronger.

The self-boiled lime sulphur is for summer use only, and has nothing
to do with the winter wash used for scale insects. The method of
making is as follows :

Place 20 pounds of lump Ume in a barrel and pour over it 3 gallons
of cold water. As soon as the slaking i; well started, add 20 pounds of



Online LibraryWalter Collins O'KaneInjurious insects : how to recognize and control them → online text (page 5 of 24)