Insects and insecticides

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Insects and insecticides.

New Pork
State College of Agriculture
At Cornell Cniversitp

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STATE HORTICULTURAL COMMISSION

ELLWOOD COOPER, Commissioner

INSECTS AND
INSECTICIDES

a

(> LIBRARY

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AUG 2 6 193

SACRAMENTO
SUPT. STATE PRI

W. W. SHANNON,’ ‘
1905

BS LE~O
CALIFORNIA STATE COMMISSION OF

HORTICULTURE.
ELLWOOD COOPER ..-..------ Commissioner ----.---------- Santa Barbara.
JOHN ISAAG cossecss cocewsaces Secretaryeccvecesusercsmeend San Francisco.
ED. M. EHRHORN -_.---.---.- Deputy co ts205 cc ecas sec cces Mountain View.
RB; Ki, CARNES! 2 2.-g22c2eeeeees Assistant Deputy -.-.----.------- Riverside.
Oo. E. BREMNER...-.---.------ Second Assistant ---.---------- Santa Rosa.
GERTRUDE BIRD ..------. --- Stenographer ...--.---.---.---- Sacramento.
OFFICE:

Room 41, State Caritot, SACRAMENTO.

Brancu Orrice, Room 11, Ferry Burtpine, San FRANCISCO.

INSECTS AND INSECTICIDES.

In order to intelligently apply insecticides, and to be able to
judge whether one remedy or another will be more effective, it
is necessary to understand something of the habits of the
different insects attacking plants. Many insects, like cater-
pillars, grasshoppers, and beetles, devour the foliage, while
others, such as scale insects, plant lice, squash bugs, etc., injure
the plant by inserting their sharp beaks into its tissue and
sucking the sap from beneath the surface. Insects of the first
class can nearly always be destroyed by means of poisons,

such as paris green and various forms of arsenates. Those of
the second class, or sucking insects, are unaffected by these
poisons and must be killed by contact sprays, such as kerosene
emulsion, whale-oil soap, crude-oil mixtures, or the lime-sul-
phur-salt' remedy. Another class of insects, and which none
of the above remedies will reach, are those which burrow into
the bark and trunks of trees. These must -be treated mechan-
ically—dug out, and barriers or repellants provided to prevent

- them from regaining entrance into the trees. In the following
pages the most successful remedies are given, but, under cer-
tain climatic conditions or in abnormal seasons, other steps
may become necessary and advice from the State Commission
of Horticulture should always be obtained in cases where any
doubt exists.

It should be remembered that the successful application of
remedies is dependent upon the exercise of proper judgment.
It is essential to first positively identify the insect to be
destroyed, then to know the most effective remedy to use, and
finally to apply it at the proper season. -Promptness, thor-
oughness, and persistency, combined with good judgment, are
the essential factors necessary for the successful application of
insecticides.

This office is at all times glad to render any assistance pos-
sible in determining the identity of insects and in advising as
to the remedy to be used for their control. Insects should not

4 STATE HORTICULTURAL COMMISSION.

Ls

be sent by mail in envelopes or pasteboard boxes, as they are
almost invariably crushed beyond recognition; strong wooden
or tin boxes should be used. Openings to admit air are not
necessary. Plant specimens, showing the injury done, are
desirable. The name and address of the sender should be on
every package. It will help greatly if correspondents, when
writing about insect pests, will give as full a description of
the habits, food plants, injury and abundance as possible.
Specimens of twigs, living plants with foliage, etc., should be
wrapped in damp (not wet) cotton cloths so that they will
reach us in fresh condition.

Correspondents can materially aid the work of this depart-
ment by informing it of their success or failure in using the
methods recommended for controlling injurious insects, at the
same time giving a detailed account of the method used and
the results obtained. Such information will prove of value to
all.

SCALE INSECTS.

These insects are among the most dreaded pests on fruit
trees in the State, owing to their prolificacy and easy mode of
transportation. They are generally firmly
attached to the foliage or bark of trees, and
when present in great numbers soon kill
the plant on which they are feeding.

All the species
in our orchards
have been intro-
duced. Although
many now have
their natural
enemies, it hav- fA
ing been the pol- RWS

many years to \
control these
pests by their" “~

Fic. 2, Pear, showing effects of
San José scale.

Fic. 1. San José scale
on twig. natural para-

sites,” yet it is
necessary, in abnormal seasons, to use artificial means to
combat them. The grower very often overlooks the few small

INSECTS AND INSECTICIDES. 5

specks on the leaves, fruit, or bark of his trees until it is too
late. The proper time for effective work is when the insects
first appear, and not after the trees are half killed by their
attack.

Nearly all species of scale insects can be killed by the reme-
‘dies recommended in this bulletin, but some species have to
be treated by fumigation with hydrocyanic acid gas; especially
is this true on evergreen trees, it being difficult, owing to the
. dense foliage, to reach every individual by sprays, and a suffi-
cient number always escape to
reinfest the trees. Our report
for 1903-04 gives a list of scale
insects and also illustrates many
species of parasites which attack .
them, colonies of which will be
supplied to growers on applica-
tion to this department.

Following are the sprays rec-
ommended for the various scale
insect pests:

Winter Wash for San Jose Scale,
Pear Diaspis, and Greedy Scale.—
Following is the lime-sulphur-
salt solution:

Unslaked lime------ 40 pounds.
SULPHUP so2sesee ese 20 pounds.
Stock salt. _,-.--.--- 15 pounds.
Water, to make ----. 60 gallons.

Place 10 pounds of lime and
20 pounds of sulphur in a boiler ‘
with 20 gallons of water, and Fic. 3. Brown ae scale (Huteca-
boil over a brisk fire for not less " ntwm armeniacum, Craw).
than one hour and a half, or
until the sulphur is thoroughly dissolved. When this takes
place, the mixture will be of an amber color. Next place in a
cask 30 pounds of unslaked lime, pouring over it enough hot
water to thoroughly slake it; and while it is boiling, add the
15 pounds of salt. When this is dissolved, add to the lime
and sulphur in the boiler, and cook for half an hour longer,
when the necessary amount of water to make the 60 gallons
should be added.

6 STATE HORTICULTURAL COMMISSION.

Rosin Wash for all Species of Scale Insects on Deciduous Trees.—
The following are the proportions of materials for the winter
wash:

MOSUL accmcecoues sacesee ee Cease oat ae un os eee 30 pounds.
Causticsoda (O87) occ ccccescaecceceisscv twos ence ceeds 8 pounds.
WishsOtl oe nae dena eh etn ees Soe eed 44 pints.
Water rtoimake ooo cacnicsatises eeccesece eescstuee nese 100 gallons.

Place the rosin, caustic soda, and fish oil in a large boiler,
pour over them about 20 gallons of water, and cook thoroughly
over a brisk fire for at least three hours; then add hot water, a
little occasionally, and stir well, until you have not less than
50 gallons of hot solution. Place this in the spray tank, and
add cold water to make the necessary amount. Never add
cold water when cooking.

Distillate Spray for Young Black Scale on Orange Trees.—To be
used with power machine, fitted with an agitator, speeded at 65
or 70 revolutions per minute:

Distillate: 28?) os.c2ccee wisceec eee ee aSciene 2 gallons.
Water nnoie ace ecateeetes eeptepuneneesteeusceeceare 100 gallons.

Use only the best 28° distillate and see that a perfect mixture
is attained at nozzle before applying to trees. This can be
determined by agitating for a sufficient time to thoroughly mix
the contents of tank; the time will vary somewhat according
to speed and construction of agitator. Examine the mixture
at nozzle by holding hand in front of same; when the mixture
is at its whitest it is ready to apply.

When engine stops from any cause, immediately discontinue
application of spray. When starting up again, empty hose
into tank until the mixture is again at its whitest. Apply
spray at a pressure of 160 pounds.

Do not spray an orchard in need of irrigation. Trees that
are not in a thrifty condition should be sprayed with a weaker
solution. .

Avoid spraying during the prevalence of high winds, cold
weather, or when trees are wet with rain or fog.

For Red Scale increase the solution to 24 per cent on orange
and to 24 per cent on lemon trees, and add one quart of pure
turpentine to the 100-gallon tank.

INSECTS AND INSECTICIDES. 7

Distillate Emulsion for Black Scale on Citrus Trees.—The follow-
ing are the proportions for the stock solution:

Distillate 28° (untreated)..--.-.----.-.-. ..----------- 5 gallons.
HOt Waters sceeeciere eee seeete sores enece een ceeeeers 5 gallons.
Witale-ouli sa prec aoe eerie oe eee See ees 14 pounds.

The whale-oil soap must first be dissolved in the water. Then
add the dissolved soap to the distillate. It is important that
the distillate be placed in the mixing vessel first, then place
the dissolved soap on top. Then attach the spray pump to
the bottom of the vessel in which the compound is being
mixed, and keep pumping it out of the vessel through the spray
pump and back into the vessel, until the whole becomes of a rich
creamy substance. Keep pumping or churning it through the
pump until it becomes a complete emulsion, without a speck
of free oil in sight, which will take from ten to fifteen minutes.
When properly emulsified, it should increase in volume about
one third, because it becomes aérified.

After the stock solution has been thoroughly prepared, it
will readily mix with cold water. To each gallon of the above
stock solution add 14 gallons of cold water: Always place the
emulsion in the spray tank first, then add the water, as by this
means a more uniform mixture can be made. This emulsion
can be applied with an ordinary hand spray pump.

Summer Wash for San Jose Scale and Other Armored Scales on
Deciduous Trees —Following are the proportions of materials
to be used:

Wehale-oil s0api.sess oscssewece netiiecseeeoeseatee sees 20 pounds.
SUI PAU wc -osssocon etc odcecemes. Gkadsececsemcescce. 8 DOUNGE:,
CaUStiC S008 98 Hors coer esa ena toss seh eee dee eee eae 2 pounds.
Waters ces ose eno eee aereetene Siem etc aeee 100 gallons.

Place sulphur and caustic soda in about two gallons of
water and boil for at least one hour. Dissolve the soap by
boiling in water. Mix the two solutions, and reboil all for a
short time. Apply the spray warm.

This wash also makes a good combination spray for scale
and fungus.

For Individual Trees and Shrubs on a Small Scale use the fol-

lowing:
W Hale-otl s0ap ice ecec cmedusoseeenereet couse neceeesecee 1 pound.
EL Ob WALER ace ete ee oc eee eee lear 5 gallons.

Dissolve the soap by boiling, and apply warm.

8 STATE HORTICULTURAL COMMISSION.

Hydrocyanic Acid Gas Treatment, for Destroying Scale Insects on
Citrus Trees.—This treatment should be used in the night so as
to avoid light, heat, and sea breeze, which neutralize the effect
of the gas. The chemicals used for producing the gas are:
Sulphuric acid (commercial), cyanide of potassium (98% to
99%), and water.

The following instructions must be carefully observed: First,
the tent, which must be air-tight, is placed over the tree;
second, the tent is made air-tight around the bottom by
throwing some loose soil over the bottom of the canvas; third,
the necessary amount of sulphuric acid, together with the
required amount of water, is put in a glazed earthenware ves-
sel, and placed under the canvas, and the cyanide of potassium
is added. A piece of sacking or burlap is thrown over the top
of the vessel, to spread the gas and prevent it from burning -
the leaves immediately above the generator. The tree is left
covered forty minutes.

The Riverside County Board of Horticultural Commis-
sioners recommends the following proportions of chemicals:

Height of Diameter of Cyanide C. P., 93 | Sulphuric Aci
Wee. Tree. Water. ‘ per cent. ‘i per fete a
Feet. Feet. Ounces. Ounces. Ounces.

2 1 1

8 6 3 1 14

10 8 5 ot ay

12 14 11 5 5s

16 16 17 8 9°
20 16-20 22 10 12
20-24 18-22 30 14 16
24-30 20-28 34 16 18
30-36 25-30 52 24 28

The cyanide should be used about the size of walnuts, so
that the chemical action will be less violent. The gas is also
generated more evenly, and there is not so much danger of the
chemicals boiling over or spattering the tent. As soon as the
tent is removed ;the vessel is rinsed with clean water and
prepared for another charge.

APHIDS,ZOR PLANT LICE.

Next to the scale insects are the aphids, or plant lice, as they
are generally called; these also belong to the sucking insects.
Plant lice are small, usually green, but varying to brown or
black insects, and are generally found on the under side of

INSECTS AND INSECTICIDES. 9

leaves or on growing shoots. These insects multiply very
rapidly, but fortunately for the grower the hot summer climate
of California prevents long duration of their attack and there
also exist in California hordes of natural enemies which attack
them shortly after their appearance and soon reduce their
numbers.

In favorable seasons, however, plant lice become a very seri-
ous pest and artificial means for fighting them have to be
resorted to. Near y all varieties of fruit trees are attacked by
them and a great many of our early fruits are rendered unsal-
able by the abundance of honey-dew exuded by these insects.

The principal known species are:

Woolly Aphis (Schizonewra lanigera).—This little insect
secretes a white cottony mass about its body and infests both
the roots and the '
branches of apple
trees. Its presence
can be readily de-
’ tected by this white
cottony mass, and
upon close examina-
tion the brownish-

pink lice are found

under the cotton. The Fig. 4. Woolly Aphis of the apple (Schizoneura
lanigera, Hausm.)

root form causes great

damage to the tissues of the roots by forming swellings or
galls, giving an unhealthy growth, which soon kills the small
roots. As the root-infesting form is by far the most destruc-
tive, it is important that remedial measures should be directed
against it. By eradicating the root form in winter a great
reduction in the branch or aérial form follows, but it can be
readily understood that this underground form is extremely
difficult to combat.

Early in the fall dig a trench around the tree, uncovering
the crown roots as much as possible; in this trench place one
or two shovelfuls of unslaked lime, according to the age and
size of the tree; add enough water to slake the lime, and cover
up with earth. The rain will keep carrying the lime to the
roots and reduce the pest. As a substitute for the unslaked
lime, gas lime is very often used, but great caution must be

10 STATE HORTICULTURAL COMMISSION.

exercised, for if applied in too great quantity there is danger
of killing the tree. One or two shovelfuls can be used on an
old tree, but a young tree should not be treated with this
substance.

The use of tobacco dust has given good results, particularly
on young trees and nursery stock. The application should be
made in the fall of the year, so that the rains can leach out the
tobacco juice and bring it in contact with the aphids.

For the branch, or aérial, form a good kerosene emulsion
or whale-oil soap wash (summer formula) will soon reduce

the pest.
KEROSENE EMULSION.

Coal:oil 60? teSt oct coseceeec ee sock ec eecececes 4 gallons.
Laundry SOa pio. sce seco see eet e ecco seeenes vesens 1 pound.
Wratel 2.0 sceccecctusscecseicevescnccuasceessdenedeeneee 2 gallons.

Dissolve the soap by boiling in the water, and when dissolved
and while boiling pour with a dash into the kerosene. Churn
the mixture for ten or fifteen minutes, either by pouring back
and forth from one vessel to another, or by pumping the liquid
back upon itself. The emulsion should have the consistency
of cream.

For a winter wash when trees are dormant, use one gallon of
emulsion to six gallons of hot water.

For a summer wash use one gallon of emulsion to ten gallons
of hot water.

Prune Aphis (Aphis prunifoliz)—These insects are readily
recognized by their bluish-green color
and by the abundance of honey-dew
generally found on the ground under
the infested trees. In abnormal! sea-
sons only does this pest become inju-
rious to the prune trees. Our native
lady-birds and syrphus flies generally
keep this species under control, but
in the absence of these friends use the
summer formula of the kerosene

Fig. 5. Prune Aphis (Aphis emulsion or the whale-oil soap ‘solu-
pruntfolizx). ti
ion.

Black Peach Aphis (Aphis persicx-niger).—This insect is
one of the most dangerous foes of the peach tree, and the
grower should, at the very start, wherever he notices its

INSECTS AND INSECTICIDES. 11

appearance, thoroughly eradicate it. It is a small brownish-
black insect and exists in the wingless as well as in the winged
form. It attacks the roots as well as the foliage, and this
makes it all the more diffi- y

cultto combat. The branch ~
form is readily controlled
by the use of kerosene
emulsion or the whale-oil
soap wash, using the sum-
mer formula; but, so far,
no wash or remedy has
been found to give perfect Fic. 6. Black Peach Aphis (Aphis
results on thé root form, persic#-niger).

only partial relief having

been obtained by the use of a diluted kerosene emulsion, used
around the base of the tree and applied during or just before
arain. This allows the water to carry the emulsion to the
infested parts. Tobacco dust, as recommended for the root
form of woolly aphis, will also give partial relief.

Hop Louse (Phorodon humuli).—The following is recom-
mended, to be applied as a spray:

Whale-oil soapiussccseiesesscetescccie: Geeseuee eet ses 7 pounds.
QUaSSIaCHIPS:.<c5- 24 -ot2e seecceteesse chek spdesesey 8 pounds.
Wisteria Jo 5 foe ee pie niente ans Saale 100 gallons.

Soak the quassia chips for eight or nine hours in hot water.
Dissolve the whale-oil soap, by boiling, and mix the two
liquids, adding enough water to make 100 gallons.

The best machine to use is the Knapsack sprayer with a
Cyclone or Vermorel nozzle, using a very fine spray and
applying it to the under side of the foliage.

CANKER OR MEASURING WORMS, TUSSOCK MOTH, LEAF-
ROLLERS, AND OTHER LEAF-EATING CATERPILLARS.

For these pests the following is recommended:

ArsenateOl lead is2 sess 5o5. clos ces Se ceetene os len 12 pounds. |
Wrealter.oce.s2ente sie ash dew este oeuvre sete ecoas 200 gallons.

Rub up the desired quantity of arsenate of lead into a
smooth, thin paste in a small amount of water, and pour into
the spraying tank or barrel. Keep the mixture well stirred
and use a fine spray with plenty of pressure. A warm, sunny
day should always be selected.

12 STATE HORTICULTURAL COMMISSION.

Cankerworms.—Two species of cankerworms do damage to
our trees, but they so closely resemble each other that it is
difficult to distinguish them in the larval form. The adult
moths, male and female, do not resemble each other, the male
being winged, the female wingless. The proper time for fight-
ing this pest is when the wingless female makes her appearance
out of the ground where she has been hibernating in the pupal
form. For years many devices have been used to prevent the
¢ female from ascending the
tree, and any substance
which will retain its sticki-
ness will be good for this
purpose. During 1905 ex-
Fic. 7. Spring Cankerworm (Paleacrita vernata). tensive experiments were

a. Male moth. b. Female moth. c. Three carried on with tree tangle-
joints of antenne of female moth. d. Abdom- 7
inal segment of female moth, enlarged. foot, a very sticky sub-

¢. Ovipositor, enlarged. stance manufactured in
the East. The results were very gratifying; in fact, tests were
made side by side with the wire-mesh trap, and the tanglefoot
gave by far the better results. The substance should be ap-
plied in early November, and is put on a paper band which

Fic. 8. Fall Eamkeawin ‘(Alsonnaia pometaria).
a. Male moth: b. Female moth. c. Joints of antenne of female,
enlarged. d. eines of body of female, enlarged. ¢. Larve of
cankerworm.

has been fastened to the tree, and when the wingless moth
crawls upon it she is held captive and soon perishes.

If through neglect in banding the trees the moths ascend to
the branches and deposit their eggs, producing a brood of
worms, the only remedy is the arsenate of lead solution.

Tussock Moth (Hemerocampa vetusta, Boisd.)—The larva of
this moth does not form a tent, as in the case of the forest-tent
caterpillar, which is often taken for it. It is generally found
singly on the under side of leaves, or along the stems of new
growth, and is a very general feeder. Gathering the white,

INSECTS AND INSECTICIDES. 13

woolly egg-clusters in pruning season has proved very success-
ful in combating this pest in certain sections, while in other

Fic. 10. Tussock Moth. Fic. 11. Tussoek

u. Female moth. b. Young larva. c. Female pupa. Moth, male.
d. male pupa.

sections it is held in check by parasites which attack these egg-
clusters. In very badly infested orchards spraying can be
resorted to, and the arsenate of lead solution will be found a
good remedy.

Tent Caterpillars—These caterpillars are at times very abun-
dant and cause a great deal of damage to the foliage of

Female moth. Larva.
Fig. 12. Tent Caterpillar (Clistocampa sylvatica).

fruit trees. The presence of the caterpillars can easily be
detected by the tents or webs which the colony of worms spin
in the tops of the trees. Collecting and burning thitse tents,

y

14 STATE HORTICULTURAL COMMISSION.

in which the caterpillars rest during the day, is about the
quickest and best method to check their ravages.

Leaf-Rollers (Cacecia sp.).—These caterpillars are gener-
ally concealed in a few leaves rolled together, and feed at night.
They have been known to do a great deal of damage in favor-
able seasons, and very often have been taken for cankerworms,
but the dark green color with a black head and the non-loop-
ing movement of the body correct this error. In orchards
where spraying with paris green or other arsenates is done
this pest soon disappears, as any arsenate spray, by poisoning
the leaves, will soon reach it.

CUTWORMS AND GRASSHOPPERS.

The following poison bait is recommended:

Brann ose ee ate a pea cceaneeasaa ees 40 pounds.
MiddiingsSicccnvse senda sctensuene wacekseeascteecdss ste! 20 pounds.
White arséni¢-< s_s..22cce8es2 22.35 Seceecscccdtacecese 20 pounds.
Cheap molassesi.cce-ew mo tsenseee= sack sctemeescoss ates 2 gallons.

Thoroughly mix the bran, middlings, and arsenic together
dry, then add two gallons of cheap molasses and sufficient
water to make the whole into a crumbling moist mash. Place
a tablespoonful of the mixture a few inches from the tree
or vine.

Cutworms (Peridroma saucia and Agrotis spp.).—Cutworms
are the larve or caterpillars of owlet moths. They feed at
night, resting underground during the day. Their natural
food is weeds, clover, grasses, etc. In wet seasons, when weeds
are abundant, cutworms are found in great numbers, and
when the grower turns under the weeds, depriving the worms
of their natural food, they will attack cultivated plants.
trees, and vines. The most successful way of fighting cut-
worms is to place a poisoned food wherever this pest is doing
damage, care being taken not to allow livestock or poultry to
run where the poison is placed. Alfalfa or any succulent
vegetable, such as cabbage or lettuce, can be dipped in a strong
solution of arsenic and water and placed on the ground around
the damaged plants, but the bran-and-arsenic remedy given

above is more generally used.

It has been found that their numbers can be greatly dimin-
ished and the loss from their depredations materially checked

INSECTS AND INSECTICIDES. 15

by gathering the worms by jarring the vines over canvas sheets
and collecting them while hoeing the weeds around the vines.

Grasshoppers.—-Grasshoppers appear periodically in large
swarms and farmers are ata loss to know what to do. This is
generally the case when the insects are on the wing, at which
time it is almost impossible to combat them. The proper time
to eradicate a swarm of grasshoppers is when they are in the
nymph or wingless stage, at which period they are slow of
motion and can be driven on to any kind of dry material and
destroyed by burning. Grasshoppers generally breed in pas-
ture lands or uncultivated fields near cultivated areas, and as
the pastures dry up they migrate to the cultivated fields. It
is absolutely necessary to check this wandering before the
insects develop wings. A great many devices have been
invented to prevent them from entering cultivated grounds,
and by the use of smudges swarms have been scattered, but
these methods have generally been used on prairie lands. If
the pasture lands are beginning to dry up and the young
hoppers are starting to move, a very successful attack can be
made by using the poison bait recommended herein.

FLAT-HEADED APPLE-TREE BORER (Chrysobothrys femorata).

Whenever fruit trees become burned they at once become
infested with the flat-headed borer, a yellowish-white grub,
with large, flat head, the larva of the
beetle. All trees, when planted,
should be placed as nearly as possible
as they stood in the nursery, for by
reversing the north side to the south
they invariably become sunburned.
Tree-protectors or a good whitewash
will prevent this trouble, if used in
time. If borers infest a tree, they must be removed and the
trunk of the tree painted with the following solution:

Unslaked! lim ¢ one eeeyecouusenercsete: ck esyhoss ees 50 pounds.
Whalé=01l S08 pia jesse siceneeeee sce ema nameueennee 12 pounds.

Fig. 13. Flat-Headed Apple-
Tree Borer.

Slake the lime with sufficient water to make a thick white-
wash; dissolve the whale-oil soap by boiling, and add this to
the lime, mixing it thoroughly; the whole should have the
consistency of cream. Apply to the trunks of sunburned trees.

16 STATE HORTICULTURAL COMMISSION.

PEACH-TREE BORER (Sanninoidea opalescens).

The larva of this insect is a pale-yellowish, cylindrical grub,
nearly an inch in length, and very destructive to the lower
trunk and roots of peach, almond, apricot, prune, and cherry
trees. Many devices and remedies have been used to check its
work, but none have proven entirely satisfactory. The worm-
ing or digging-out method, although very expensive, is no
doubt the most reliable one, and when followed by the appli-

LEH! ¢4,
Uhh

Female.

Pupa.
Fic. 14. Peach-root Borer (Sanninoidea opalescens).

cation of a barrier, or preventive, to keep out the new brood,
which is absolutely necessary, has given good results.

In the digging-out method, the earth should be removed
from around the tree and wherever gum is found, the borer
chisel should be carefully used and the borers removed, care
- being taken not to remove too much bark. The proper time
to do this is in November, December, or January. After the
trees have been thoroughly gone over, a barrier compound
should be applied. The following two mixtures have given

good results:
: Mixture‘No. 1.

Unslaked lime ._.-.-.--...--.--.---------------------- 50 pounds.
Whale-oil/soapinss22cstonevcsent sutidzessc antes eddeeds 12 pounds.
COM RAR. cess tous ntachedote neues encccselcamesen ad 13 gallons.

To make the compound, slake the lime and tar together,
adding enough water to make a medium thick whitewash.
Dissolve the soap with hot water and add this to the lime
solution, using enough water with the mixture to make a
thick, paste-like whitewash.

Mixture No. 2.

Unslakeéd Mime «.2-..c602 4) ccsceesee ss cee Ske cots idence 50 pounds.
Crude oil, 16° Beaume -.-.--...----- .--- -------------- 3 gallons.

Slake the lime and crude oil together, adding enough water
to make a thick whitewash.
The application of crude oil alone (14° or 16° Beaume) will

INSECTS AND INSECTICIDES. 17

successfully drive out or kill the small borers, but does not
seem to affect those that are full grown. The constant appli-
cation of crude oil alone to trees, especially in warm localities,
should be avoided, as experience has shown that it is detri-
mental to the bark.

STRAWBERRY AND CURRANT BORERS.

These pests usually attack
old plantings. The best rem-
edy for the strawberry borer
is to dig up, as soon as discov-
ered, the plants showing in-
festation. In the case of the
currant borer, the infested
canes should be carefully re-

moved below the point of | Pupaand Larva. ph
pnraabati di diatel Fie. 15. The Currant Borer (Zgeria
Intestation and immediately tipuliformis).

burned.
PEACH MOTH (Anarsia lineatella).

The sudden wilting of the young, tender growth of peach,

Fic. 17. Peach Moth (Anarsia
¢ tineatella). ©
Fic. 16. Peach Moth (Anarsia lineatelia). a. Egg. b. Young larva. ec. Eye.
a. Moth with spread wings. b,c. Same with d. Thoracic leg of same. e. Anal
wings closed, illustrating positions normally segment from above. All greatly
assumed. All muchenlarged. (After Marlatt.) enlarged. (After Marlatt.)

apricot, and prune trees is caused by a small -reddish-brown
worm, the larva of the peach moth. This worm hibernates

18 STATE HORTICULTURAL COMMISSION.

during the winter months in the soft bark of the crotch of the
tree, and can be killed by the use of the lime-sulphur-salt
solution, or by a good kerosene emulsion. Care should be
taken to select sunny weather and spraying should be put off
as late as possible, preferably just before the swelling of the
buds. Either spray will penetrate the burrows and kill the
small worm.

CODLING-MOTH (Carpocapsa pomonella.)

The larve of the codling-moth, or worm of the apple, pos-

i sibly do as much
damage to the ap-
ple and pear crops
in this State as
anything which
attacks fruit trees.
Thorough spray-
ing, clean culture,
== and collecting all
fallen fruit go far

toward coping

Fic. 18. Codling-Moth (Carpocapsa pomonella), :
ie in ale. oe with the pest. The

———

newly introduced
parasite, Calliephiates messer, Gray., has already taken hold
of this pest in
several sections
and may prove Sie,
a great aid in |: i
keeping it in-
check in the
future. During
the present sea-
son the arse-
nate of lead
seems to be the
leading spray
materialin use,
owing to its ad-
hesive properties. This material in a prepared form and
ready for use simply by the addition of water in sufficient
quantity, is on the market in different sized packages. A

4 x. B\ ap
wie wie

Fig. 19, Codling-Moth (Carpocapsa pomonella).
Showing variations. All natural size.

INSECTS AND INSECTICIDES. 19

great deal of disappointment in the use of paris green gener-
ally occurs, on account of either poor material or unfavorable
weather conditions. The weather does not seem to have the
same effect on the arsenate of lead as it does on other sprays,
and storms do not seem to remove this poison, as it is not sus-

ceptible to the rain.
Mixture No. 1.
Arsenate of lead__-_..--..--.---.... -._....------ 8 to 12 pounds.

Wikiteltn sete ooo see loco ci AS ace Pi cers 200 gallons.
Make the arsenate of lead into a smooth, thin paste by using
the necessary amount of water, then pour into the spray tank,
and keep well stirred while spraying. Use a fine spray with

plenty of pressure.
Mixture No. 2.

Paris @TGGM en een eG Stee see cee eseees 1 pound.
Unislaked Mime:e2 22s. cs. peacusmessnedeenewentace sceels 6 pounds.
Wiate? <2csn5c congccos sceameeecckdemmeeedasoniadecacce 200 Rallons,

Make the paris green into a — ‘beter placing it in the
spray tank. Slake the lime with plenty of water and strain
thoroughly so as to eliminate all particles which might clog up
the nozzle. Place the lime solution and paris green in the
tank with the water and stir the mixture constantly while
spraying. Lime water alone has been used, but it is preferable
to use the lime, as it shows when the trees have been sprayed
thoroughly.

PEAR OR CHERRY SLUG (Lriocampa cerasi).

When the pest first makes its appearance, especially on
young trees, a good dusting with air-slaked lime or, better,
hydrated lime, will check the damage. Spraying with arsenate
of lead, as recommended for cankerworms, will be found very
efficient on larger trees.

CABBAGE WORMS, CUCUMBER BEETLES, DIABROTICA, AND
FLEA BEETLES.

The following are recommended:

Wet Sprays.
(1) Arsenate of lead.-..6 to 8 pounds. (2) Paris green ._.-..--..- 1 pound.
Wrater:..s-2scesese5 ced 100 gallons. Unslaked lime. __-.--- 2 pounds.
Wiiler sa en esos 160-200 gallons.
Dry Sprays.
(1) Paris green -_.. --..---- 1 pound. (2) White arsenic_.--.---- 1 pound.
Hydrated lime, air-. Hydrated lime, air-
slaked lime, or wheat slaked lime, or wheat

MOUP scase tote eas 10 pounds, AOUM So eo cs ees 12 pounds.

20 STATE HORTICULTURAL COMMISSION.

Both the wet and the dry sprays, when thoroughly mixed,
will be found very efficient in eradicating these pests by either
dusting with the dry compound or spraying in the regular
manner with the wet solution.

SQUASH BUG (Anasa tristis); HARLEQUIN CABBAGE BUG (Jur-
gantia histrionica); BOX ELDER PLANT BUG (Leptocoris trivittatus).
These insects are too well known to need description. The

females, which hibernate during winter in dried leaves and

weeds along fences, lay their eggs on the under side of the
leaves or on the stems of young plants. To be successful in
fighting these pests the hibernating females must be gathered
before they lay their eggs, thus preventing the spring brood
from making its appearance. This has been done on a large

NZ
BP. Ne
St

Fic. 20. Harlequin Cabbage Bug (Murgantia histrionica).

a. Larva. 6. Pupa. c. Eggs, natural size. d. Eggs, enlarged. e¢. Eggs seen from
above, enlarged.

scale and is the only true way of preventing the enormous
increase which generally occurs where these pests are let alone.
In case the spring brood makes its appearance, about the only
available method is hand picking or jarring them into recepta-
cles containing kerosene. Where the pest is very numerous
the planting of early trap crops has also been found quite
successful.

HESSIAN FLY (Cecidomyia destructor).

This is one of the pests which, in favorable seasons, appear
in our grain fields and it does considerable damage to the grow-
ing grain. The adult fly is a small black gnat, resembling
somewhat the mosquito on a very small scale. The female
deposits her eggs on the leaves and leaf-stalks of the sprouting
grain. These eggs, which are very minute, are pale orange in
color, with reddish dots, and are laid with the head end
downward. As soon asthe tiny grub hatches, it goes down the
stem and forces itself between the stem and the sheath ag near
the joint as possible. At this point the grub makes its attack

INSECTS AND INSECTICIDES. 21

by sucking the sweet juices of the stalk, which soon wilts and
falls over. After the grub has attained its full growth it
passes into a brown pupa form, which resembles a flax seed,
and the empty pupa case is left protruding from the stalk
after the fly has emerged.

Where this pest has appeared it is advisable to burn off the
stubble in the fall, as this will destroy the “flax-seed” pupe,
which hibernate in the stubble. It is also advisable to sow
the grain as-late as possible.

GARDEN SLUGS OR SNAILS.

Although slugs or snails do not belong to the same sub-king-
dom as insects, yet the damage which some of them inflict on
vegetables and other products of the gardener and florist is
sufficient to cause mention of these pests in this bulletin. They
are generally found in damp places, hiding under stones and
in cracks of the ground in daytime. In the evening they come
from their hiding places in search of food, and as they are
voracious feeders, they often do great damage. .

At sundown thoroughly drench the garden. Place pieces of
board, shingles, or even cabbage leaves on the beds where the
damage has been done. The slugs will congregate on the under
side of these traps instead of returning into the wet soil and
can easily be killed in the morning. Spreading fresh slaked
lime on the ground around the plants that have been attacked
will act as a repellant, but if much watering is done the lime
will soon be washed away.

RED SPIDERS AND MITES.

Red spiders appear as minute red, reddish-brown, or yellow |
specks on either the surface or the under side of the leaves and
by the aid of a hand lens are easily recognized. The eggs
are generally laid in masses on the under side of branches and
around the buds, this being particularly true of the almond
bryobia. The damage done by these minute creatures can
easily be noticed. The mites suck the sap from the cells of
the leaves, which take on a pale color and finally drop to the
ground. The following remedies have been used to advantage:

For Red Spider or Yellow Mite on Deciduous Trees.—Soon after
the trees are in leaf in the spring, and while they are damp

22 STATE HORTICULTURAL COMMISSION.

with dew in the morning, thoroughly dust them with sulphur:
Use sulphur bellows, or if the orchard is extensive, fix up a
broadcast seeder on a wagon. With this arrangement an
orchard can be treated very thoroughly and with dispatch.
Infested orchards should be treated at least three times during
the spring and early summer.

While this is true generally, sometimes the dry sulphur does

Fig. 21. Yellow Mite. Fic. 22. Pear-Leaf Blister Mite (Phytoptus pyri), very
greatly enlarged.

not seem to do the work, owing to climatic conditions, and it is
best to apply the sulphide of potash wash, as follows:

Caustic soda 98% ...-..---------------------- ------ ...- 10 pounds.
SUIPRUM 2 os ossco2 ese seeeees woes ceseescuteeseraasesiee 20 pounds.
Dissoly ein: water 2scvessoscccas. docnewe ates Sete ssercea 20 gallons.

Take the sulphur, mix it to a paste—not sloppy-—with cold
water ina barrel, then add to this wet sulphur 10 pounds of
caustic soda (98 per cent), and it will boil the sulphur just like
lime slaking; have 20 gallons of water to add to it as it boils,
to prevent its burning. This is the stock solution, and when
ready to spray the mites or spiders, put 40 gallons of water in
another barrel, and take a half gallon of the stock solution
and add to the 40 gallons of water, straining it to take out any
sediment there may have been in the sulphur. Remember,
this is for mites and spiders only. This stock solution should
be diluted one-half gallon to 40 gallons of water, and applied
with a spray pump under 100 pounds pressure.

The distillate spray of 2 per cent strength with the addition
of 7 pounds of flour of sulphur has proved very effective in
some sections of the State. To use the sulphur in this mixture,
it is necessary to first make a paste of the sulphur before adding
it to the distillate mixture.

For Pear-leaf Blister Mite, Walnut-leaf Blister Mite, Grape-leaf
Mite, Orange and Lemon Peel Mites—The burrowing mites, or
Phytoptt, differ from all the other mites in having but two

INSECTS AND INSECTICIDES. 23

pairs of legs, always located near the head (see figure), whereas’
the “red spider” (Tetranychus) has three pairs in the young
stage and four pairs in the adult, located upon the sides.
The body of the Phytoptus is cylindrical, transparent, and
long, as compared with the other portions of the mite. From
the position of the legs it has to drag its body in walking.

Kerosene emulsion is considered the most effective wash for
winter use. It is very effective when diluted with from three
to eight parts of water and sprayed on the infested trees or
vines before the leaves start. Trees sprayed with the strongest
solution are practically free from this pest. Those sprayed
with the weaker solution show very few galls—not over one
per cent of the number that were on the trees the preceding
year. Summer treatment with liquid remedies is of little avail.
As soon as the leaves start in the spring they should be liber-
ally treated with dry sulphur in the early morning while yet
damp with dew; a second and third application as the growth
develops will be found effective.

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