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THE WORE IMPORTANT
SHADE TREE INSECTS
OF EASTERN CANADA
AND THEIR CONTROL

EVJUlSwaine and CBilufcfiings

DOMINION OF CANADA

DEPARTMENT OF AGRICULTURE

BULLETIN No. 63 — NEW SERIES

I ed by direction of the Hon. W. R. Motherwell. Minister of Agriculture, Ottawa. April. 1926

.C212
S'Z J

ENTOMOLOGICAL BRANCH

Dominion Entomologist Arthur Gibson

Associate Dominion Entomologist J. M. Swaine

Division of Forest Insects J. M. Swaine (in charge)

Chief, Division of Foreign Pests Suppression L. S. McLaine

Chief, Division of Systematic Entomology J. H. McDunnough

Chief, Division of Field Crop and Garden Insects H. G. Crawford

LABORATORIES

Annapolis Royal, N.S Headquarters for Insecticide Investigations: Arthur Kelsall,

Entomologist in charge.

Fredericton, N.B Field Crop Insect Investigations: R. P. Gorham, Assistant Ento-
mologist in charge.

Insecticide Investigations: G. P. Walker, Assistant Entomologist
in charge.

Forest Insect Investigations: L. J. Simpson, Junior Entomologist
in charge.

Hemmingford, Que Fruit Insect Investigations: C. E. Petch, Entomologist in charge.

Aylmer, Que Forest and Shade Tree Insect Investigations: C. B. Hutchings,

Assistant Entomologist in charge.

Vineland, Ont Fruit Insect Investigations: W. A. Ross, Entomologist in charge.

Strathroy, Ont Field Crop Insect Investigations: H. F. Hudson, Assistant Ento-
mologist in charge.

Chatham, Ont European Corn Borer Parasite Investigations: A. B. Baird, Assist-
ant Entomologist in charge.

Treesbank, Man Field Crop Insect Investigations: Norman Criddle, Entomologist

in charge.

Indian Head, Sask Forest and Shade Tree Insect Investigations: J. J. de Gryse,

Assistant Entomologist in charge.
Live Stock Insect Investigations: Eric Hearle, Assistant Ento-
mologist in charge.

Saskatoon, Sask Field Crop Insect Investigations: K. M. King, Entomologist in

charge.

Lethbridge, Alta Field Crop Insect Investigations: H. L. Seamans, Entomologist

in charge.

Agassiz, B.C Field Crop and Fruit Insect Investigations: R. Glendenning,

Junior Entomologist in charge.

Vernon, B.C Forest Insect Investigations: Ralph Hopping, Entomologist in

charge.
Fruit and Field Crop Insect Investigations: E. R. Buckell, Ento-
mologist in charge.

Victoria, B.C Fruit Insect Investigations: W. Downes, Assistant Entomologist

in charge.

(ENTOMOLOGICAL BULLETIN No. 28)

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White Elm, Ulmus americana, Linn.
Courtesy of Forestry Branch, Department of Interior, Ottawa.

The More Important Shade Tree Insects of Eastern
Canada and Their Control

By J. M. Swaine and C. B. Hutchings

INTRODUCTION

The shade trees of our cities, towns and villages are attacked each summer
by many insect enemies, and more or less seriously injured thereby. Very
frequently the foliage is disfigured for a great part of the season through un-
sightly webs and partly eaten leaves, and very often dying branches and ruined
trees are the final result.

The losses incurred in this way are chiefly in the beauty and comfort pro-
vided by the trees, and while this may be difficult to express in dollars, the
injury is none the less a very real one. A good shade tree requires many years
to grow and demands a certain care and attention; apart from its aesthetic
value it has also a definite money value. The courts have established the
worth of well grown shade trees at as much as several hundred dollars each;
and since thousands of shade trees are ruined and killed each year in Canada
by injurious insects, the actual monetary loss incurred in this way amounts
to a very large sum.

The shade tree insects of Eastern Canada include borers in the bark and
wood of the trunk and branches, and leaf-feeding insects of various kinds, such
as caterpillars, leaf-beetles, sawfly larvae, plant lice, scale insects, gall-making
insects and various others.

It is possible to control most insect attacks on trees which are valuable
enough to warrant individual treatment; but very many of these injuries could
be prevented by proper handling of the trees, and considerable expense and
trouble could thus be avoided.

SELECTION AND PLANTING

Mistakes are often made in selecting the trees for planting. Good stock
should be chosen of varieties which are suited to the climate and soil conditions
of the location. Trees which are likely to succumb to local insect pests should
be avoided. It is almost useless, for instance, to plant the white birches in
districts where the bronze birch borer is abundant. For city planting, elms,
maples, oaks, basswood and ash are most suitable.

The trees should be planted carefully and properly* and an abundance
of water should be furnished the roots in dry seasons. The weaker, unthrifty
trees should receive special attention, or should be replaced. Vigorous trees in
full sap are much better able to withstand the attack of destructive borers,
and are, of course, more likely to recover from attacks by defoliating or sucking
insects, or from injuries of any sort.

TREATMENT OF WOUNDS

Protection from injuries and the proper treatment of damaged trees are of
the utmost importance. Whenever the bark is broken and left untreated,
insects and fungi are almost certain to gain entrance. Many of the most serious
injuries from decay originate from wounds through which the parasitic fungi
enter. Broken branches should be trimmed off smooth and even with the trunk;
and the bare surface, unless very small, should be coated with creosote and tar
(1 part creosote mixed with 2 parts tar) or with a good paint that does not con-

*The Planting and Care of Shade Trees, Dominion Experimental Farms, Dapartment of Agriculture, Ottawa, Bull.
No. 19.

16859-2

tain turpentine (pure white lead and linseed oil), thoroughly covering the entire
wood surface excepting the junction between the living outer wood and the inner
bark, which should be left uncoated. Very small wounds may be covered safely
with grafting wax. Wounds on the trunks or limbs should be smoothed off and
similarly coated. Any needed pruning should be done during the dormant
period of the tree.

Injury from wind and sleet storms can be lessened by chaining or bolting
weaker upright branches together or to the trunk. Reasonable care in the pre-
vention of injuries and in the proper treatment of affected trees will prevent
much trouble from boring insects and fungous rots.

Trees which have been badly injured by decay can be saved in many cases
by proper surgical treatment. The decayed portions should be entirely removed
and the healthy surface thus laid bare thoroughly disinfected with creosote,
excepting the junction between the bark and wood, which may with advantage
be coated with a ring of shellac immediately after the cut is made. The parts
should then be bolted together if such support is required, and the cavity filled
with cement. It is best to have any important work of this kind done by an
expert in tree surgery, if such services are available.

Trunks of city trees frequently require protection from injury by horses and
by vehicles. Guards of stout metal fencing are effective. Pavements of con-
crete or asphalt should not be extended close to the trees. A large circle of bare
ground should be left about the trunk for the admission of air and water.

CLEAN CULTURE

All dying and dead branches and trees should be removed and burned.
Many insects and rot-causing fungi breed in such material and emerge therefrom
to attack weakened or even healthy trees. It is of the utmost importance to
cut out or collect and burn all such material promptly so as to destroy the pests
which it contains. Each fall and winter remove all dying and dead trees and
branches and burn them before spring. Make it a rule to cut out and burn
unhealthy wood as soon as detected. Time and labour spent on this work will
be well repaid.

INSECT STAGES

Insects are jointed, air-breathing animals. In the adult stage there is a
distinct head, a thorax and an abdomen, one pair of antennae attached to the
head, three pairs of jointed legs and usually one or two pairs of wings attached
to the thorax, and mouth parts which are variably adapted for biting, sucking
or lapping.

Most insects reproduce by means of eggs, although a few, such as aphids
and sawflies, deposit living young.

In some species (grasshoppers and bugs) the young stages, called nymphs,
resemble the adults more or less closely in appearance. They change the skin
several times, increasing in size and similarity to the adult at each moult, and
finally reach the adult stage, usually winged, after which there is no further
change in size or shape.

The young stages of other species (flies, bees, moths and beetles) may be
entirely different in appearance from the adult; they may lack the wings, and
in many species the jointed legs, or, in some, even the mouth parts. In these
insects the young is known as a larva. The larvae of beetles arc1 called grubs;
those of flics are called maggots; those of butterflies and moths are called cater-
pillars and those of sawflies slugs or false-eater p ill 'a rs.

The larva, after reaching full growth, changes to the resting stage or pupa,
which finally transforms to the adult insect. The pupa may be1 naked, as the
chrysalis of a butterfly, or, surrounded by a cocoon constructed of silk, earth or
chips, as in the case of some moths and beetles, or, by the hardened last larval
skin (puparium) as in the two-winged flies.

NATURAL CONTROL

( )ur shade tree insects are in most cases native species which are normally
found in the forests. Some of them are of little importance in large areas of
woodland, but become exceedingly troublesome under the more or less isolated
conditions of cultivated trees, where there is little opportunity for distribu-
tion, and the attack of the pests is relatively concentrated. The spruce gall
aphids are abundant very often in spruce forests but cause no evident injury,
while on spruce as shade and ornamental trees they are very destructive enemies.

On the other hand, some of our most injurious shade tree enemies have been
introduced into this country from the United States, or, originally from Europe.
The larch sawfly, the brown-tail moth, the gypsy moth, the elm and alder leaf
miners, the mottled willow borer, the satin moth and the elm bark-louse are
examples of these troublesome immigrants. In their native country these
insects are held more or less effectively in check by special parasitic and pre-
daceous enemies and in some cases it has been found necessary to import into
this country certain of these useful parasites and predators to aid in coping with
the introduced pests.

Changed conditions about centres of population have driven away the
insectivorous birds and thereby favoured the development of insect outbreaks.
Every effort should be made through protection and the provision of nesting
boxes and watering places, to encourage song birds to remain about thickly
populated districts.

Also, changed conditions in the forest, produced by our civilization, have
apparently favoured in different ways the development of forest insect epidemics,
and these have, in some measure, affected our shade trees.

Some of our shade tree insects occur periodically in outbreaks lasting for
one, two or three years in succession, and then disappear almost completely for
several years. The reason is they are overcome by their natural enemies and
other natural control factors, which include parasitic and predaceous insects,
bacteria and fungi, birds, adverse weather conditions, and lack of food on the
defoliated trees. For several years following the cessation of the outbreak, the
injurious insects may be almost rare; then they gradually begin again to increase,
until, finally, when the most favourable conditions for their breeding occur, they
multiply with tremendous rapidity and an epidemic condition consequently is
again produced. The important function of beneficial insects is to hinder the
increase of injurious species and thus to help in preventing the development of
great outbreaks; but, unfortunately, the parasites and predators are rarely
able to check an extensive outbreak of injurious insects before great injury has
been caused to the trees, and artificial measures of control are, therefore, often
necessary.

ARTIFICIAL CONTROL

Injurious insects feed either by biting off parts of the plant with their jaws
or by sucking the juices through a slender beak inserted into the tissue. The
biting insects, such as beetles, caterpillars, and sawfly larvae, which feed upon the
foliage, are usually killed most easily by spraying the infested foliage with a
stomach poison, such as arsenate of lead. The sucking insects, as for example
plant lice and scale insects, are not affected by stomach poisons and must be
sprayed with insecticides which kill by contact, such as nicotine sulphate or oil
emulsions.

SPRAYING

The methods and materials employed in spraying shade trees are much the
same as those required for the treatment of trees in the orchard, except that
frequently greater heights have to be reached, and consequently a more powerful
apparatus is required. For spraying the lower foliage the ordinary nozzles and
equipment may be used; but to reach the top of the higher trees it is necessary
to employ a solid stream spray and a powerful pump of large capacity.

A number of types of spraying machines are now on
the market. In purchasing these one should consider the
nature of the work to be done, the amount of pressure
attainable, and the different accessories required for
ordinary or special work.

Bucket pumps (fig. 1) if well constructed, especially
if they have a fairly large air chamber, are capable of
developing considerable pressure. They are effective
in treating a limited number of very small trees or shrubs.

Barrel pumps (fig. 2) have a wider range of useful-
ness than bucket pumps. A good pump of this type
equipped with a 25-foot line of hose, an eight-foot exten-
sion rod and a drive spray nozzle may work effectively
for trees up to a height of about 20 feet, or much higher
if a ladder and a longer hose be used. A straight nozzle
about 4 inches in length with a very small bore gives the
best results.

BUCKET PUMP | ro,-
snrubs ana Very t
sma/J trees.

JFrc,y,*cl

Approximate pr/t*

J g.00

Fig. 1. — Bucket pump.
(After de Gryse.)

Double action hand pumps (fig. 3)
are practical for spraying shelter
belts and also street trees in small
towns. They are more powerful than
the ordinary barrel pump and mav
be used with tanks of 120 to 200 gal-
lons capacity. The types now on the
market can be geared to a small gaso-
line engine and are best used in that
way, since they are somewhat diffi-
cult to operate by hand. In spraying
tall trees the nozzle must be carried
well into the top, necessitating the
use of a long hose, ladders and climb-
ing irons.

For large operations a power
sprayer is indispensable (fig. 4). A few

Fig. 2. — Barrel pump. (Aft cm- de ( I ryse.

of the power spray-pumps sold for orchard
work will maintain a solid stream for 50
feet up from the nozzle; other pumps
excellent for general work in the orchard,
have a small pumping capacity and are
unable to maintain a solid stream much
above 30 feet. By using a good straight
drive nozzle, long hose, and elevating the
nozzle on a platform or ladder, the aver-
age orchard power sprayer can be made
fairly effective for reaching shade trees of
moderate height.

For towns and cities, where large
numbers of tall trees are to be sprayed,
special power sprayers designed for shade
tree purposes should be obtained. Several
types of these powerful pumps are now
available, capable of maintaining a solid
stream from 80 to 100 feet up from the nozzle. The essential requirements of
an efficient shade tree sprayer are: a high pump capacity, preferably more than

Fig. 3.-

-Double action hand pump.
(After de Gryse.)

20 gallons per minute, and an engine capable of maintaining continuously a
nozzle pressure of 225 pounds. Very strong hose and special couplings are
necessary for this work on account of the high pressure employed. Straight
bore nozzles, such as the "Worthley", are required to deliver the solid stream
of spray which breaks high in the air into a fine mist. A special attachment is
employed to break the spray closer to the ground when spraying lower foliage.
The crew for spraying in city streets should include an experienced foreman, an
engine man, a driver, a nozzle man, and several hose carriers, as the length of
hose may require.

In spraying for shade tree insects thoroughness is an absolute necessity. A
mist spray at high pressure should be employed for as high as the extension or
spray gun will reach, and for the higher portions the solid stream is necessary.
The latter uses the spray mixture very rapidly and should be employed with
discretion. It is, of course, essential to understand the habits of the insects to
be controlled and to apply the sprays at the proper time.

Fig. 4. — Power sprayer. (After de Gryse.)

INSECTICIDES

STOMACH POISONS

Arsenate of Lead is the safest and most satisfactory insecticide for the con-
trol of biting insects on shade trees. It is sold in the form of a paste and also as
a powder, the powder being about twice as strong as the paste and more com-
monly employed. The paste should be guarded from drying and from freezing.
The addition of a small amount of soap to the spray will cause it to adhere
better and to spread more evenly. The formula for ordinary use is: — ■

Arsenate of lead powder \Yi pounds

or Arsenate of lead paste 3 pounds

Soap (laundry or fish-oil) 1 pound

Water 40 gallons

Mix the required amount of poison with a little water before adding to the water
in the spray tank, add the soap dissolved in a small amount of hot water, and stir
the whole thoroughly. For resistant forms the poison may be used as strong as
8 pounds of paste or 4 pounds of powder in 40 gallons of water. For small
quantities use 2 teaspoonfuls of powder in one gallon of water.

16859—3

CONTACT INSECTICIDES

Nicotine Sulphate is one of the most satisfactory contact sprays for use
against many sucking insects, particularly plant lice. Its effectiveness is in-
creased by the addition of a small amount of soap. Commercial prepara-
tions may be obtained containing 40 per cent of nicotine sulphate. This is used
at different strengths; the formula for common use is: —

Nicotine sulphate M "to 3^2 pint

Soap (laundry or fish-oil) 2 pounds

Water 40 gallons

Kerosene Emulsion was formerly the standard remedy for use against plant
lice and other sucking insects. It is troublesome to prepare, but the ingredients
are always readily obtainable, and it is, therefore, useful in emergencies.

A stock solution is prepared and may be kept for some time. The spray
material is made by mixing a portion of the stock solution in the required amount
of water.

Stock solution: — ■

Kerosene (coal oil) 2 gallons

Laundry soap 3^2 pound

Water 1 gallon

Heat the water, cut the soap into fine shavings and add to the water, stirring
till all the soap is dissolved; then pour this into the kerosene and churn the
whole violently with a syringe or force pump until a thick creamy emulsion is
produced. This makes the stock solution, which must be diluted with water
when being used as a spray. As the stock solution cools it thickens into a jelly-
like mass.

Soap Solutions may be employed as contact insecticides; but they are used
chiefly in emergencies and when only a small amount of spray is needed.
Specially prepared insecticidal soaps may be purchased or the less effective,
but easily obtainable laundry soap may be used instead. Soap solution is of the
greatest use in controlling plant lice and is prepared by dissolving one pound of
soap in 5 to 8 gallons of water.

Miscible or Soluble Oils may be obtained which mix readily with water.
They are particularly effective on shade trees in the control of scale insects,
being applied usually during the dormant period of the tree. The spray solution
for dormant trees is made by mixing 1 part of the oil in 15 parts of water for
most scale insects, and 1 to 20 for spruce gall aphis. The miscible oils should be
applied to conifers only with great caution, and hard maples are also reported
to be particularly susceptible to injury.

POISONED CONTACT SPRAY

A poisoned contact spray is often effective in controlling borers in the bark
and wood of living trees. To prepare the spray solution, add one ounce of dis-
solved sodium arsenite to each gallon of contact spray, such as kerosene emulsion
or miscible oil. This is sprayed on the infested trunks and branches so as t<>
soak into the tunnels as far as possible. The foliage should not be sprayed with
the mixture.

DUSTING

The application of poisons in the form of dasts is effective on the lower
foliage of shade trees, employing the methods used in dusting orchard trees.
A hand dusting machine may be used for treating shrubs and very small trees.

HAND PICKING

This method of treatment necessarily has its limitations. The tents of the
American tent caterpillar and the fall webworm can be removed by means of
tree-trimmers or torches; egg-masses of the tent caterpillar can be removed b\
hand, at times, with profit; the eggs of the white-marked tussock moth and of
the gypsy moth can be painted with creosote; galls of the spruce gall aphis, on
small trees, can be removed by hand while still green; and the larger caterpillars,
which rarely occur in great numbers, can sometimes be removed from low
foliage by hand more cheaply and effectively than in any other way.

THE DESTRUCTION OF LARGE WOOD BORERS

When living trees become infested with large boring grubs or caterpillars
it is necessary to kill the borers in their tunnels with the least possible injury to
the trees. When the borers are near the surface it is often possible to cut them
out with a knife or chisel without much injury to the wood. A wire thrust into
the borings can sometimes be used effectively. It is usually possible to kill the
grubs by injecting carbon bisulphide or benzine into the openings. The fluid
should be injected with a syringe or oil-can and the opening immediately plugged
with soap or putty. After several hours the holes may be opened; the grubs
removed if easily reached; decaying wood cut away; the holes thoroughly dis-
infected with creosote or with a solution of bichloride of mercury, and finally
filled with cement. The carbon bisulphide or the benzine, should be injected
into the flatter holes from which sap and borings have been oozing and which
evidently lead to the tunnels of living larvae. It is useless to inject insecticides
into the exit holes from which the adults have escaped, although such holes
should be disinfected and filled with putty or cement.

Many of these borers feed repeatedly near the surface, enlarging their
tunnels, and it is possible to kill some of them by spraying the infested trunks,
or branches, with poisoned oil emulsions.

BANDING THE TRUNKS

Banding the trunks of deciduous trees to prevent infestation from wander-
ing hordes of caterpillars or from wingless females of the cankerworms is often
a necessary precaution. The most effective method is to make a complete
girdle about the trunk with a sticky substance over which the insects cannot
crawl. The adhesive should be applied in a band about four inches wide to
stout paper tacked or tied about the trunk about five feet from the ground. If
the bark is uneven cotton should be placed beneath the paper to prevent the
insects passing beneath; or a portion of the trunk may be scraped smooth and
the adhesive applied directly on the bark. One of the best adhesives for banding-
is made by boiling resin and castor oil in equal parts and thoroughly mixing.
The well known preparation "Tree Tanglefoot" is widely used for this purpose,
and can be obtained from dealers in insecticides. The common sticky fly paper,
tied about the trunk, is effective for a time. A band of cotton batting tied
about the trunk with a strong string so that the upper half hangs down over the
tie is also useful.

16859— 3*

10

Leaf-eating Insects

The Forest Tent Caterpillar
(Malacosoma disstria Hubn.)

These caterpillars occur periodically in great infestations, feeding upon the
foliage of poplar, willow, birch, ash and other hardwood trees. Vast areas of

poplar forests are at times
almost completely defoli-
ated for several years in
succession, the trees being
disfigured for a large part
of the season and finally
weakened to a serious de-
gree. Since the feeding
occurs early in the season
the trees develop a second
growth of leaves during
August; they are able,
therefore, to recuperate in
some measure before win-
ter. After the foliage has
been stripped from large
areas the starving cater-
pillars swarm, over the neigh-
bourhood in search of food
to the great annoyance of
the inhabitants.

Fig. 5. — American tent caterpillar moths, above; forest

tent caterpillar moths, below, o71 , male; d\ female.

(After Swaine.)

The caterpillars hatch from the eggs on the first warm days in spring about
the time the buds are opening, and immediately commence feeding on the
young leaves. In colour they are bluish-grey with a row of elongate whitish
spots along the back. They become full grown in June, spin yellowish silken
cocoons between the leaves or in any protected place, and pupate therein. The
small, chocolate-brown moths
emerge from the cocoons in

late June and earlv July and ,^~-^» *^ .^,k

deposit their eggs in ring-like j||

eggs in eaca, around the
twigs of trees. The eggs re-
main on the twigs during
winter and hatch early in the
following spring.

Control. — Pruning off and
burning the egg-masses dur-
ing fall and winter is effective
if the work is thoroughly
done. This plan, however,
is frequently not feasible on
large trees on account of the

abundance of egg-masses on „ . , . , .„„,,,

rhP in-n mnd K,,n„l1M \ Fig. 6.— 1. American tent caterpillar. 2and 3. forest

tlR top-most blanches. A tent caterpillar. (After Swaine.)

11

dozen neglected egg-masses will furnish a
large number of caterpillars.

Spraying the infested trees with arsenate
of lead at the rate of V/2 pounds of powder
in 40 gallons of water, as soon as the cater-
pillars appear in the spring, is the most de-
pendable method of control. If the cater-
pillars are half grown before the spray is
applied, 23^ pounds in 40 gallons of water
should be used. Clustering or migrating
caterpillars may be destroyed by crushing
with a stiff brush attached to a long pole,
or by spraying with strong kerosene emul-
sion, or with kerosene when the masses of
caterpillars are off the trees.

Banding the trees after spraying affords
additional protection from wandering cater-
pillars and is necessary when the latter are
abundant.

Fig. 7. — Egg masses of forest tent
caterpillars. (After de Gryse.)

Fig.

-Cocoons of forest tent caterpillar.
(After de Gryse.)

The American Tent Caterpillar
(Malacosoma americana Fabr.)

This species is closely allied to the fore-
going. The caterpillar has a white line
down the back, replacing the row of spots
of the forest tent caterpillar. It is a com-
mon orchard pest and is frequently found on
wild cherry and hawthorn. The caterpillars
are gregarious and spin a regular and con-
spicuous silken "tent" in the junction of
branches, within which they retire at night
and in wet or cold weather. This species
feeds only in the early part of the season and
is frequently confused with the later appear-
ing fall webwoim.

Control. — As above, combined with prompt
destruction of tents containing the caterpillars.

The Maple Leaf-Cutter

(Paraclemensia acerifoliella
Fitch)

Extensive outbreaks of this
species have occurred during
the past few years in the sugar
bushes of Quebec and Ontario.

The caterpillar is protected
by an oval case formed of four
layers cut from the leaf. It
skeletonizes the leaf in a sub-
circular ring about the case and
then moves to another location,
the injured portion of the leaf
frequently falling out and leav-
ing a hole nearly half an inch
in diameter. The larvae feed
from July to September, and
when full grown descend to the

ground, pupate within their Fig. 9.— Tent of American tent caterpillar. (After Swaine.)

12

cases, and hibernate below the surface litter. Late in May of the following
year, the minute steel-blue moths emerge and deposit their eggs in the leaves,
and the young larvae excavate mines between the leaf surfaces, emerging in

about two weeks, to construct the
case within which the remainder of
the larval and the pupal life is passed.
In severe outbreaks the maples
are defoliated to a considerable de-
gree for several years in succession,
with a consequent disfiguration and
loss of vigour.

Control. — Burning the leaf litter
after all the leaves have fallen should
destroy the majority of the hibernat-
ing insects. It should be possible to
burn the leaves thoroughly without
injury to the trees if the litter is
raked away from the trunks and the fire carefully guarded. Where possible,
this work should be done in the afternoon as the wind is less likely to rise then
than during morning hours.

Serious defoliation can be prevented by spraying thoroughly as soon as the
injury becomes apparent, with lead arsenate powder, l}/£ pounds in 40 gallons
of water.

Fig. 10. — Maple leaf-cutter moth, greatly enlarged.
(After Hutchings.)

Fig. 11.— Work of the maple loaf-culler on sugar maple. After Hutchings.)

13

The Spring Canker Worm (Palaeacrita vernata Peck)
The Fall Canker Worm (Alsophila~pometaria Harris)

These small caterpillars occur periodically in great numbers and often
completely defoliate maple trees for several years in succession, disfiguring
and frequently killing the trees. Elm, ash, oak, willow,
birch and fruit trees are also severely injured.

The caterpillars are slender, light or dark brown
and green in colour, marked with narrow stripes.
The species known as the fall cankerworm has three
pairs of prolegs at the rear end of the body and the
one known as the spring cankerworm, two pairs.
Owing to their peculiar method of locomotion, due to
the legs being at the front and hind ends of the body,
they are known as measuring worms, or loopers. They
appear early in spring when the buds are opening and
feed voraciously on the tender foliage. During June
they become full grown and drop to the ground to
pupate beneath the surface. In the case of the fall
cankerworm, the majority of the moths emerge from
the pupae late in the autumn. The females are
wingless, greyish in colour, about J/£ inch in length.

They crawl up the trunks

of the trees and deposit

their eggs in clusters on

the branches and trunk.

The moths of the spring

cankerworm appear early

in the following spring and

have the same general

. habits.

/ fl&Sit species are very delicate

/ IkSS? moths, greyish in colour, the fore-wings darker than

****** the hind-wings, and have a wing expanse of slightly

more than an inch.

Control. — Tanglefoot bands should be applied
about the trunks late in September to prevent the

ferSfe moTh^iSgedTtoes. ascent of the wingless females to deposit their eggs.
(After siingeriand and Crosby.) The bands should be kept fresh by combing each

week until winter, and freshened or renewed in early

spring before the buds open. When

the moths are abundant, their bodies

bridge the neglected bands so that

late appearing females may cross in

safety. Owing to the habit of the

young larvae of drifting considerable

distances on threads of silk, pro-
tected trees may become infested

from neglected groves in the neigh-
bourhood. In that case, it may be

necessary to supplement the banding

by arsenical sprays.

Fig. 12. — Fall cankerworms.
The males of both (After Siingeriand and Crosby.)

If the trees have not been protected
by banding or the caterpillars are

■ \.'*dB^H

K' ^^Sl^B

^^^^^f^K^Wt":^^^ A

Kt^SI

■k4 'jr .» T.. .' '_ "-'3^3SS?. j|

WW%m&i-?s'5i. SiaFiH

■yaU#SS^-S«?

'JEw** ■..*..!... sr " .-*:.• v i_j^B

^B^: " jfr ja£

^m ' 1 ■•- ^m

»^ ^

H. ^H

Fig. 14. — Fall cankerworm, male moth, twice
enlarged. (After Siingeriand and Crosby.)

14

already feeding when discovered, the foliage should be sprayed very thoroughly
as soon as the leaves are about one inch long, with lead arsenate at the rate of
2 pounds of the powder in 40 gallons of water. In some cases it may be necess-
ary to repeat the spray. If the spraying is delayed until the caterpillars are
half-grown, twice as much poison should be used. Special care should be taken
to cover the upper foliage very thoroughly with the arsenical.

The Gypsy Moth
(Porthetria dispar Linn.)

This species was introduced into the United States from Europe about
1870 and since that time has spread throughout a large part of the New England
States and as far north as southern Quebec.

The gypsy moth caterpillars feed upon a wide variety of plants. The apple
is the favourite food plant, but a preference for oak, birch, willow, elm, and
poplar is shown. More than 500 different kinds of plants, however, are known
to be eaten by them, including practically every native tree and shrub in Eastern
America.

Enormous sums of money have been spent in the United States in the
attempt to control this most destructive pest and prevent its distribution;
nevertheless, the infestation has been spreading slowly westward and northward
until finally, in the summer of 1923, a colony of the gypsy moth was discovered
in Vermont within half a mile of the
Canadian line. During the summer of
1924 a careful survey was conducted in
southern Quebec and one small colony
was discovered near Lacolle within a
few miles of the international border.
Very thorough measures were taken to
eradicate this infestation and it is
hoped that the work will prove com-
pletely successful.

The presence of this colony warns us
that we must maintain a vigilant
watch for the introduction of the pest.
It is only through careful, very prompt
and vigorous control measures that we
can hope to prevent the establishment

in southern Canada of this most dreaded and destructive species. Success will
depend upon the prompt recognition of the insect, so that measures for its
extermination can be instituted before the infestation becomes established over
a large area.

A short description of the moth and its caterpillar will be given here with
an account of the habits; this together with the illustration in figure 16 will
aid in identifying the species. Any specimens of egg-masses, moths or cater-
pillars suspected of belonging to the gypsy moth should be reported at once
to the Dominion Entomologist, the specimens being retained safely until mailing
directions are received.

The female moth is stout, cream-coloured, with dark zigzag lines on the

inches in expanse. Although well developed
The male moth, an active flier, is smaller and
brownish-yellow, varying to greenish-brown in
colour with dark markings. The eggs are deposited in flattened, elongate masses
containing several hundred individual eggs in each, on tree trunks, stone walls,
buildings and similar places. Each egg-mass is covered with the buff-coloured
hairs from the underside of the female's bodv.

w-*^B

kAi

gg^^sj

i

?^j^

St M

| ^Oj

3^

S

X

1

^'tPN

&*d

rj£

L JJ

hL

Jf

%J2rm

3^

l^^*. 1

rjtA

LJr2

lUm

Wtm.

^St *]^!

Fig. 1"). — Portion of vu.il mass of fall cankerworm,
much enlarged. (After Slingerland and Crosby.

wings, which are are about 2
the females are unable to fly.
more slender than the female,

15

7s f^*«

Fig. 16. — Gypsy moth. (After Rane.)

16359-4

16

The caterpillar is about two inches long when full grown, clothed with long
black and yellow hairs, the ground colour pale brown with two rows of blue and
red tubercles along the back and a similar row along each side of the body.

The life history in brief is as follows: winter is passed in the oval egg-
masses; hatching occurs during May and June and the caterpillars feed upon
the foliage for about six weeks; when full grown they pupate as brownish
chrysalids suspended by silken threads and covered by a loose web ; the moths
appear in middle and late July and deposit the egg-masses which hibernate and
hatch in the following spring.

In severe infestations the caterpillars occur in vast numbers and may
defoliate nearly all shade and ornamental trees and woodlands in the neighbour-
hood. Even conifers are injured when in mixed plantations. The trees are dis-
figured for a large part of the season and many of them are killed by repeated
defoliations. Great annoyance, also, is caused by the myriads of caterpillars
and egg-masses about houses and buildings. Although the female moths, as
said before, do not fly, the infestation may be distributed over the country very
rapidly. The young caterpillars float readily on the wind and are dispersed in
this way for many miles. The larger caterpillars may be carried in automobiles
and other vehicles, and the egg-masses are readily transferred on shipments of
lumber, stone and like materials to which they have been attached.

It has been found that temperatures lower than 20 degrees below zero
Fah., have apparently destroyed many of the eggs in exposed places, but the egg-
masses situated below the snowline and in other protected locations may be
expected to survive even very low temperatures.

Control. — When the gypsy moth was introduced into America its native
insect enemies were left behind and it is probably on that account that it has
proved so much more destructive on this side of the water. For a number of
years the United States Government have been importing European parasites
of the gypsy moth in great numbers and have introduced them under the most
favourable conditions into the infested area of New England. Several of these
parasites have been imported into Canada and bred in our parasite laboratory
to be liberated later in infested areas. The beneficial effect of this work is already
apparent and its importance and value should greatly increase in future4 years.

Control operations include the destruction of egg-masses during the dormant
season by collecting them or by painting them with creosote; banding the trees
to collect the caterpillars and moths; and spraying the infested foliage witli
arsenate of lead at the rate of 2 pounds of powder in 40 gallons of water, when
the caterpillars are small, or at the rate of 3 pounds in 40 gallons, if they are
nearly half grown.

The Brown-tail Moth
(Euproctis chrysorrhoea Linn.)

This insect was introduced into Massachusetts from Europe about 1897,
and has since become an important enemy throughout a large pari of the New-
England States. It was recorded in New Brunswick in 1910, and subsequently
spread to many parts of that province and into Nova Scotia. A vigorous
attempt was made by the Dominion and Provincial Governments to check the
infestation by destrojdng the winter nests of the caterpillars. Although the
work is still being conducted on a small scale in the Annapolis Valley of Nova
Scotia, the infestation there has been greatly reduced, while the insect has
practically disappeared from the Province of New Brunswick.

The adult insect is a pure-white moth with a reddish-brown tufl on the end
of the abdomen; it has a wing spread of \\ to If inches. The eggs are deposited
in masses, each containing about 200 eggs, covered with brownish hairs from
the abdomen of the female and attached to the underside of the Leaves. The cater-
pillars are about 1| inches long when mature, dark brown in colour, with brown

17

and white hairs arranged on the tubercles. The hairs are barbed and poisonous,
giving rise to an irritating rash on contact with the skin. The caterpillars pass
the winter partly grown in a winter nest formed of neighbouring leaves fastened
together and to the twig with silk. In the spring the caterpillars resume feeding
on the foliage. They become full-grown by the first of July and pupate in
crevices, the moths appearing therefrom about three weeks later to mate and

THE BROWN-TAIL MOTH

ITS DIFFERENT STAGES FROM EGG CLUSTER TO THE ADULT MOTH
NATURAL SIZE AND COLOR

Fig. 17. — Brown-tail moth. (After Rane.)

deposit their eggs. The young caterpillars appear in late summer and feed for
several weeks before constructing their winter nests. The moths fly very long
distances and the species is thus capable of rapid distribution.

The caterpillars feed upon fruit trees and many deciduous trees, particu-
larly the maple, oak and elm; when abundant they are very destructive.

16859-41

18

Control. — Collecting and burning the nests during the winter months is an
effective method of control. When necessary this is supplemented by spraying
the infested foliage in August while the caterpillars are small with powdered
lead arsenate, 2 pounds in 40 gallons of water. If spraying is delayed until
spring the strength of the arsenical should be doubled.

The Spiny Elm Caterpillar

(Aglais antiopa Linn.)

This is the caterpillar of the common mourning-cloak butterfly. It feeds
on the foliage of elm, willow, poplar, birch, and basswood, and sometimes

causes serious defoliation.
The caterpillar is about
2 inches long when full
grown, black, sprinkled
with small white dots and
marked with a row of
large red spots along the
middle of the back and
on the base of the abdom-
inal legs. Each body
segment bears several
black, branched, danger-
ous-looking though harm-
less, spines. They feed
in groups, during the
early part of their life and later disperse over the tree, pupating finally as
chrysalids, attached by the hinder end to branches, or any convenient solid
object. The butterfly is dark maroon in colour with a yellow border about the
wings within which is a row of blue spots. The eggs when first laid are yellow
and turn black before hatching. They are deposited in bands on the twigs.
There are two generations, the first in July, the second in September. These
insects pass the winter in the adult stage in protected places and appear in the
following spring among the earliest butterflies of the season.

Control. — When control measures are required, spray the infested foliage
with arsenate of lead at the usual strength.

Fig. 18. — Spiny elm caterpillar (After de Gryse.)

Fig. 19. — Work of birch leaf skeletonise!". (Original.)

19

The Birch Leaf Skeletonizer

(Bucculatrix canadensi sella Chamb.)

This insect is commonly found on birches, chiefly the white and yellow,
throughout Eastern Canada and occasionally becomes epidemic. From 1921
to 1923 a severe outbreak occurred throughout a large part of Ontario, Quebec
and the Maritime Provinces.

The yellow-green caterpillars, less than one-fourth of an inch in length,
occur in late summer and skeletonize the birch leaves, causing severe defoliation
when very abundant. Upon hatching, the young larvae mine between the upper
and lower surfaces of the leaves; they then spin small but conspicuous, flattened,
white, silken moulting-cocoons, attached to the leaves. After attaining full
growth the larvae lower themselves by fine threads to the ground and spin tiny,
ribbed, boat-shaped, silken pupating-cocoons on the underside of leaves or other
protecting objects among the leaf litter. The small, light-brown moths appear
towards the middle of the following July and deposit eggs on the underside of
the leaves.

Control. — Injury to cultivated birches may be prevented by spraying the
infested foliage with lead arsenate.

The Satin Moth
(Stilpnotia salicis Linn.)

This insect was introduced into the New England States from Europe a
few years ago and has since spread over a large area in the States of Massachu-
setts and New Hampshire. In 1920 an infestation was discovered at New
Westminster, B.C., and the infested area now extends to the city of Vancouver,
and along the east coast of Vancouver Island.

The caterpillars feed on the foliage of poplars and willows. In British
Columbia the injury has consisted of a partial defoliation of poplars in towns
and villages, during the early season, but has not yet been particularly severe.

Hatching occurs in July and August; the young larvae feed for a short
time and then hibernate in silken cases in crevices in the bark, or elsewhere.
They emerge about the end of the following April and feed upon the foliage
until July and pupate when full grown. They are black in colour with a row of
white spots along the back.

The pure-white moths appear from the first of July onward. (See fig. 20).

ConZroZ-'Spraying with lead arsenate will prevent serious injury.

The White-marked Tussock Moth
(Hemerocampa leucostigma Sm. and Abb.)

The larvae of this species feed voraciously on the foliage of a number of
deciduous shade trees specially the maple, basswood and elm. They are par-
ticularly numerous and very injurious about cities and towns.

The caterpillar is beautifully marked, with a coral red head, a yellow band
along each side, and a row of four conspicuous brush-like tufts of white or yellow
hairs along the back. They hatch late in May, or early in June, and at once
begin feeding upon the leaves. The caterpillars frequently drop to the ground
from defoliated branches and seek other trees. Towards the latter part of July
they pupate in cocoons attached to the bark of the trunk and branches or to
nearby objects, and about two weeks later the adult moths appear. The female
is wingless and deposits several hundred eggs in a conspicuous whitish mass
upon the cocoon from which she has emerged. In this latitude the eggs mostly
remain upon the trees unhatched until the following spring.

Outbreaks of these caterpillars occur periodically in many of our cities
and towns, usually giving rise to considerable alarm, and were their ravages
allowed to increase unchecked we should lose our finest shade trees.

20

Fig. 20.— Satin moth. 1. Moth on poplar trunk. 2. Larvae hatching from
egg-mass. 3. Life-history stages. (After Glendenning.

21

Fortunately, the caterpillars are attacked by many insect parasites, and

often these beneficial insects succeed in destroying the caterpillars before the

most serious injury has been caused. Nevertheless, many valuable trees suffer
very severely in these outbreaks.

Fig. 21. — White-marked tussock moth. 1. Egg-mass. 2. Caterpillar. 3. Wingless female on
egg-mass. 4. Male moth. (From Bulletin 312, Geneva Agric. Exp. Station.)

Control. — The infested foliage should be sprayed with lead arsenate powder,
2 pounds in forty gallons of water, while the caterpillars are small, before much
of the foliage is injured. One thorough spraying should be effective unless the
poison is washed off immediately by heavy rains.

22

A simple and effective method on small trees is to collect and destroy the
egg-masses. These are whitish and easily detected upon the bark after the
leaves have fallen. Valuable parasites breed within the eggs and in order to
avoid destroying many of these it is better to collect the egg-masses in the early
spring, before the eggs hatch in May, and to leave them in loose containers at
a considerable distance from valuable trees until July. The more valuable trees
should be further protected from wandering caterpillars by banding with cotton
batting or "tree tanglefoot." Perfect removal of the egg-masses (impracticable
on large trees) or thorough spraying with lead arsenate as soon as the caterpillars
appear, combined with banding the trunks, will protect isolated trees.

The Fall Webworm

{Hyphantria cunea Drury)

The conspicuous, unsightly webs of this species are usually abundant
throughout many parts of Eastern Canada during the latter part of the season.

Fig. 22.— Webs formed by caterpillars of fall webworm. (After Tothill.)

The caterpillars feed collectively upon many varieties of deciduous tree-.
particularly the ash, elm and willow, and cover the foliage with an irregular,
silk-webbing, often extended to cover the entire branch, causing injury and
disfigurement to the trees.

The caterpillars are about 1J/9 inches long when full grown, distinctly
clothed with whitish hairs arising from black and orange warts scattered over
the body; pale yellowish or greenish in colour, with a wide, dark stripe along the
back and a yellow band along the sides. In the latter part of the summer the
caterpillars become full groAvn, descend to the ground, spin thin cocoons under
rubbish or beneath the surface of the ground, pupate therein, and emerge as
small white moths early in the following summer. The moths deposit yellowish
eggs on the underside of the leaves and the caterpillars appear therefrom in a
little more than a week.

23

The webs of the American tent caterpillar with which this injury is fre-
quently confused occur early in the season.

Control. — The webs may be removed while very small by stripping off by
hand, or by means of tree-trimmers, and the contained caterpillars destroyed by
crushing or burning. Burning the webs by means of a torch made of a bundle
of rags attached to the end of a pole and saturated with kerosene may be used
effectively. The most satisfactory method of control is to spray the infested
branches with arsenate of lead at the usual strength.

The Hickory Tussock Moth

(Halisidota caryae Harr.)

The black and white hairy caterpillars of this species are occasionally
abundant on elm, birch, ash and other hardwood trees. The young caterpillars
are gregarious and frequently defoliate an entire branch; the larger ones feed
individually.

Control. — They can be controlled by spraying with lead arsenate.

Fig. 23. — Hickory tussock moth. •
(After Swaine.)

Fig

24. — Hickory tussock caterpillar.

(After Swaine.)

The Spotted Tussock Moth

(Halisidota macidata Harr.)

The caterpillars of this species are covered with tufts of bright black and
yellow hairs; they are general feeders, but prefer oak, willow and poplar.

Control. — They can be controlled by spraying with lead arsenate.

.■:■ W " ■'•:>

Fig. 25. — Spotted tussock moth,
(After Swaine.)

Fig. 26. — Spotted tussock caterpillar.
(After Swaine.)

16859—5

24

The Black Walnut Caterpillar
(Datana integerrima Grote and Robinson)
The black walnut caterpillar is sometimes abundant on black walnut,
butternut and hickory. The caterpillars are black, about two inches in length
when full-grown, covered with long white hairs, and have the habit of turning up
both ends of the body when disturbed. They feed in large groups and some-
times cause considerable defoliation.

Fig. 27. — Moth of walnut caterpillar,
slightly reduced. (After Hutchings.)

Fig. 28. — Walnut caterpillar.
(After Hutchings.)

Control. — Spray the foliage with lead arsenate, or collect the larvae when they
settle on the trunk or branches, in dense masses to shed their skins.

Fig. 29. — Walnut trees defoliated by caterpillars. (After Hutchings.)

The. Yellow-necked ( Jaterpillar
(Datana ministra Walk.)
The caterpillars of this species, while they have a preference for the apple,
are general feeders on shade trees, particularly maple, elm, walnut, hickory and
butternut.

They are black in colour, striped with narrow, yellow, longitudinal lines, and
with a bright yellow neck. This last characteristic gives the insect its name.
I -ike their near relative, D. integerrima^ they live in groups. This is particularly

25

noticeable during the moulting periods. The moth is reddish-brown and nearly
two inches in wing expanse. Eggs are laid in June.

Control. — Same as for the black walnut caterpillar. See previous paragraph.

The Spruce Budworm
(Cacoecia fumiferana Clem.)
The spruce budworm is an important forest enemy in Eastern Canada and
has been reported as injuring ornamental spruce, balsam and hemlock. The
small caterpillars feed
upon the opening buds,
and later upon the
needles, which they tie
together with silk.
The injury to many
buds checks the sea-
son's growth, and the
dying, partly-eaten
leaves, with the excre-
ment and silk spun
irregularly by the lar-
vae, give the trees a
scorched appearance
and detract largely
from their beauty.

Control. — Spray with
lead arsenate as soon
as the injury becomes
apparent. This method
applies only to trees
valuable enough to war-
rant individual treat-
ment.

Fig. 30.— Mass of yellow-necked caterpillars in characteristic
(After Hutch ings.)

pfj.se.

The Green-striped Maple Worm

(Anisota rubicunda Fabr.)

Red-headed caterpillars, 1}^ inches long, yellowish-green with dark green

stripes, and armed with short, black spines on each segment and two long.

black horns on the second segment behind the head, occur at times in great

numbers on maples.

The Yellow-striped Oak Caterpillar
(Anisota senatoria Sm. and Abb.)
Black, yellow-striped caterpillars, about 2 inches in length, with black
points on each segment and two, long, black horns from the second segment
behind the head, are often abundant in June and July on oaks.

The Red-humped Oak Caterpillar
[Symmerista albifrons Sm. and Abb.)
Caterpillars, nearly 2 inches long, striped with black, yellow and lilac, with
a large red hump on the eighth abdominal segment, are sometimes common on
oak, maple and beech late in the summer.

The Antlered Maple Caterpillar
(Heterocampa guttivitta Walk.)
Caterpillars, lJ/£ inches long, marked in green, yellow and purple, occasion-
ally defoliate maple sugar bushes and other hardwoods. A severe outbreak
occurred in southern Quebec in 1922.

16859-5!

26

The Green Maple Caterpillar

(Xylina antennata Walk.)

Light green caterpillars with whitish markings are sometimes abundant on
soft maples and other hardwoods.

Control of Defoliating Caterpillars. — Defoliating caterpillars, such as those
just named, may be controlled by spraying the infested foliage with lead arsenate,
13^2 pounds of powder in 40 gallons of water.

The Larch Case-bearer
(Coleophora laricella Hubn.)

This insect sometimes disfigures ornamental larches, specialty in Eastern
Canada where it may be considered an injurious pest. The larva of the case-
bearer is a tiny caterpillar of most interesting feeding habits. It begins operations
by eating out a portion of a larch needle which it then cuts off, lines with silk, and
carries about with it as a portable house, covering the hinder part of its body.
Leaf after leaf is then excavated through a round hole cut in the side by the
caterpillar to permit the entrance of its body. The caterpillars retire to the
twigs before the needles drop in the fall, and pass the winter in their cases,
which are firmly attached to the bark with silk.

Where the attack is severe the dried and yellow excavated needles sadly
disfigure the trees, and at times an injurious loss of foliage results.

Control. — The injury may be prevented by spraying trees which were badly
infested the preceding season and upon which the winter cases are numerous,
with lead arsenate spray just as the young needles are appearing in the spring.
Later in the season poison sprays will not be so effective, owing to the small
extent of leaf surface eaten by the caterpillars; but an application of kerosene
emulsion, one part of the stock solution to nine parts of water will kill a great
number of them.

The Larch Sawfly
(Lygaeonematus erichsonii Hart.)

This is a very destructive enemy of native and European larches. The
caterpillar-like larvae feed upon the foliage during early summer, and severe
defoliation for several years in succession weakens and eventually kills the
trees. The curved twigs, caused by egg-scars, and the ban1 and brownish appear-
ance of the trees in summer, distinguish the injury.
The larvae are two-thirds of an inch long when full
grown, greenish in colour, the head black, the body
usually curved like a bent finger. The adult insect is a
dark, four-winged fly, appearing early in spring to
deposit its eggs in a row of slits along one side of the
developing shoots, causing the latter to curl in a char-
acteristic manner. The larvae pass the winter in oval,
tough, brown, silken cocoons, two-thirds of an inch in
length, in the moss beneath the trees.

Control. — The larvae feed in clusters and on a few
small trees may be hand picked and destroyed by crush-
ing or dropping into a pail of water and kerosene.

When many trees are involved it is necessary to
Fig. 31.— Charaeteiistic curling spray the infested foliage thoroughly with arsenate
of end shoot caused by the 0f \Q.M\ iX\ the rate of 1 ! •> pounds of powder in 40 gallons

egg-laying adult of the larch -. ■ , ,.ul ill

sawfly. (After deGryse.) of water, with a little soap added.

27

The Elm Sawfly
(Cimbex americana Leach)

The larvae of this sawfly feed upon the foliage of willow, elm, maple and
poplar. The adults are reported to gnaw into the twigs and thus often injure
the plant by girdling the stems, giving the tops a characteristic appearance
of having been swept by fire.

The larvae, which resemble caterpillars, are
yellowish-white in colour and have a conspicuous
black line along the middle of the back. They have
eleven pairs of legs, eight of which are on the ab-
domen. When full grown they attain a length of
2 J inches, leave the food plant and form their cocoons
among decaying leaves or loose soil under the
trees. There they pass the winter, pupate in spring
and appear as large, wasp-like, four-winged flies in
May. The females deposit their eggs singly in pockets
cut into the leaf tissue and the young larvae hatch
in about eight days.

Control. — Burning rubbish under the trees in
April will destroy many of the over-wintering insects.
In small willow plantations and on small trees hand
picking the larvae from the infested leaves may also
be effective. The most satisfactory method, how-
ever, is spraying with arsenate of lead at the rate
of V/z pounds of powder in 40 gallons of water, as

^.-i i ,' i ' Fig. 32.— Elm sawfly larva.

soon as the larvae are noticed. (After de Gryse )

LeConte's Pine Sawfly

{Neodiprion lecontei Fitch)

Not infrequently, pines are seriously defoliated in early
summer and in autumn by the larvae of this sawfly, which
are found feeding in clusters in July and sometimes in Septem-
ber and October. They are of a dirty yellowish colour with
the head reddish and black spots along the back and sides.
When full grown they crawl to the ground and pupate in
tough, silken cocoons under rubbish. The winter is passed in
this condition. The adults, dull, tawny-yellow, four-winged
flies, first appear in May and lay their eggs in slits in the
needles.

Control. — In small plantations and on isolated small trees
remove the larvae by hand and crush them or drop them into
a pail of water and kerosene. When larger areas and trees are
involved spray the foliage with arsenate of lead at the rate of
13^2 pounds of powder in 40 gallons of water, with a small
amount of soap added.

Abbott's Pine Sawfly

(Neodiprion pinetum Norton)

The larvae of this species are nearly an inch in length, the

head black, the body yellowish with four longitudinal rows of

Fig. 33.— LeConte's black spots. They feed on the foliage of pines and have habits

pine sawfly similar to those of LeConte's sawfly.

(After deVGryse.) Control. — The same as for LeConte's sawfly. (See above.)

28

The Fir Sawfly

{Neodiprion abietis Harris)

In this species the larvae are striped with dark green, with a black head,
about half an inch long when full-grown, found feeding in midsummer on fir
and spruce.
Control. — The same as for LeConte's sawfly. (See above.)

The Alder Leaf-miner

(Kaliosysphinga dohrnii Tisch.)

This species, closely allied to the elm leaf-miner and with
similar habits, is abundant about Ottawa on cultivated alders.
The adults appear and deposit eggs in the leaves during late
May or early June and again in July, and flies have been seen
ovipositing in September.

Control. — The injury is prevented readily by spraying the
infested foliage, as soon as the mines appear, with kerosene
emulsion at the rate of one part stock solution in five parts of
water; one part stock to seven parts of water is effective when
applied immediately after the eggs are hatched.

The following varieties of alder have been found immune
from attack: Alnus serrulata, A. carpinus betula, A. oblongata
and A. macrophylla.

The Elm Leaf-miner

(Kaliofenusa ulmi Sund.)

FlG' 34' la^vaSawfly Tnis recently introduced elm pest has become established

(After de Gryse.) in southern Ontario and southern Quebec. The larvae ex-
cavate blotch mines in the leaves of elms and when abundant
they destroy a large part of the foliage and render even large trees unsightly
for a great part of the summer. (See fig. 36).

The adults, small black sawflies about one-eighth of an inch in length,
appear late in May and deposit their eggs through the upper epidermis of elm
leaves. The legless larvae extend their mines between the two surfaces of the
leaf, producing a characteristic blistered appearance. Attaining full growth
about July 1 they leave the mines and spin small silken cocoons below the surface
of the ground, within which they pass the winter, and transform to the pupae
and then to the adults in the following May. There is reported to be only one
generation each year.

Control. — The injury can probably be prevented on trees valuable enough
to warrant the treatment by spraying in early June, as soon as the minute
blisters appear, with nicotine sulphate and soap, or with kerosene emulsion,
one part of the stock solution in seven parts of water.

The European Poplar Sawfly

(Trichiocampus viminalis Fabr.)

The larvae of this introduced insect feed chiefly on the foliage of Carolina
poplars. They are yellowish with black spots, a black head and white hairs
and attain a length of about three-fourths of an inch.

Control. — Lead arsenate is recommended if control is required.

29

M\

9-

>s

co

«r

f.

*

<*

cd .S

« .s

t- ft

T3 .C

*3

30

The Lilac Leaf-miner

(Gracilaria syringella Fabr.)

The adult of this miner is a brown moth, 34 -inch in length, which appears
early in June, during the evening hours, and lays its eggs on the underside of
the young leaves. The grub is at first a miner and feeds between the upper and
lower leaf surfaces, causing them to turn brown and bladder-like. Later it
comes to the exterior, rolls the leaf and feeds therein, sometimes six or more

Fig. 36. — Work of elm leaf-miner. (After Chrystal.)

larvae working together. As a consequence the shrubs are badly disfigured.
There is a second generation early in September, the larvae of which are
even more injurious.

Control. — Nicotine sulphate should be applied when the leaves first show
signs of the larval work, in the proportion of l^ tablespoonfuls of nicotine To
one gallon of water. Follow this with a stronger solution two weeks later.
if necessary. The work should be carefully done and the branches well covered.
Picking off and burning the spotted leaves early in the season will help in cheek-
ing the spread of the injury.

31

*

Fig. 37.— Leaves injured by lilac leaf-miner. (Original.)

The Yellow-spotted Willow Slug

(Pteronus ventralis Say)

This is one of the worst enemies of the willow, particularly
to young growth. Swellings on the upper sides of the leaves
indicate the spots of oviposition. The eggs produce black,
slug-like larvae which feed in groups on the foliage, stripping
it completely. Pupation occurs in two or three weeks in the
ground within a dark brown, shining cocoon from which the
adult fly later emerges after a week in the resting stage.

Control. — Whenever abundant this species can be con-

trolled by a spray of
40 gallons of water.

\}/2 pounds of lead arsenate powder to

The Elm Leaf-beetle

(Galerucella xanthomelcena Schrank)

This important enemy of both European and American
elms is reported to be well distributed in the eastern United
States, but has not yet been found in Canada. The greenish,
black-lined beetles, about one-fourth of an inch long, and
their grubs feed upon the foliage of elms during June and July. FlG- 38-~ The Yeliow-

r J spotted willow slug;

Control — The injury may be controlled by spraying the Larvae feeding on
infested foliage with lead arsenate. (Afterde Gryse.)

32

Fig. 39. — Poplar leaf beetle, showing
variations. (After Riley.)

The Cottonwood Leaf-beetle
(Lina scripta Fabr.)
This species is abundant in many seasons, feeding in both adult and larval
stages on the foliage of poplars and willows.

The adult is a somewhat flattened,
elongate and rounded beetle, a little less
than half an inch in length. The wing-
covers are golden-yellow with elongate
dark, longitudinal markings, varying to
nearly black throughout; the thorax is
black with a reddish or yellow border;
the under surface is dark green.

The yellowish eggs are laid on the
undersides of the leaves and hatch in
about 10 days. The grubs are about one-third of an inch long when full grown,
soft-bodied, yellowish in colour with darker head and legs. They feed upon the
undersides of the leaves and complete their growth in about two weeks. The
pupae are attached by the hinder end of the body to the undersides of leaves
and other objects. There is apparently more than one brood each season. The
beetles pass the winter beneath rubbish on the ground and in protected places.
They appear in May, feed upon the opening buds and foliage and deposit their
eggs- ^ . n

This species sometimes se- /^rflllliiiil^^^S ^^L

verely defoliates shade and

ornamental trees and fields of ,, ■ / * <

basket willows.

Control. — Spray the under-
sides of the leaves with lead
arsenate, 2 pounds, soap 1
pound, in 40 gallons of water.
In fields of basket willows a
beetle-collecting machine is
recommended which brushes
the beetles into pans of kero-
sene as it is moved along the
rows.

.f

Fig. 40. — Work of poplar leaf beetle larvae. (After Riley.)

The Spotted Willow Leaf-beetle
(Lina interrupta Fabr.)
This species is of the size and form of the preceding, but in colour has the
wing-covers yellowish to reddish with rows of square or transverse black mark-
ings; the thorax black with a yellow or red border and the under surface black.
Its habits and life-history are much the same as described for Lin a scripta.
Control. — Use the arsenate of lead spray as above.

The Arborvitae Leaf-miner
(Argyresthia thuiella Pack.)
Dying tips of the leaves of white cedar, or arborvitae, are frequently caused
by the mines of tiny yellowish caterpillars, one-eighth of an inch in length.
The adults are very small white moths with black spots on the wings. They
emerge about the first week in July and lay their eggs on the inner edges of the
leaves during the middle of that month, and the larvae excavate a small area
between the upper and lower leaf surfaces where they hibernate without other
protection. In spring they continue feeding, reach full growth in June and
pupate about the middle of the month.

33

Control. — In some seasons this leaf miner disfigures ornamental cedars
so seriously that control measures are desirable. Clipping off and burning the
dried tips in fall or early spring would account for
many larvae. Kerosene emulsion sprays have no
effect, but a strong tobacco-soap solution applied in
July has been recommended for young larvae.

June Beetles
(Lachnosterna spp.)
June beetles are the adults of white grubs, one of
the worst pests the farmer has to combat. They
feed freely on the foliage of many shade trees. The
adults are robust, clumsy, reddish-brown beetles
which may be found flying around lights during the Fig. 41.— Arborvitae leaves show-
warm evenings of May and June. Maximum flights ins location of eggs deposited by

occur every three years. One of these took place in (original.) &

Much enlarged.

1925, maple, elm, and other trees in eastern Quebec
being literally stripped bare by the ravages of the beetles. These flights are of
short duration, and subsequently the beetles bury themselves in the earth, lay
their eggs and die. The eggs hatch into tiny, white grubs which feed on the
roots of plants. These remain below the ground for three seasons, transform in
the fall and emerge the following May or June.

Control. — Lead arsenate, \Yi pounds to 40 gallons of water, applied when
the beetles are first noticed will kill large numbers. Jarring the trees and
destroying the beetles as they fall to the ground by drowning them in kerosene
and water is to be recommended.

Fig. 42. — Life-history stages of June beetle, (a) beetle; (b ) pupa; (c) egg; (d) young grub; (e) full
grown grub; (f) anal segment of same from below. (After Chittenden.)

The Walkingstick Insect

(Diapheromera femorata Say)

Oak, basswood, hazel, maple and other deciduous trees are attacked by this
insect. It is frequently found in limited numbers in groves, woodlands and
parks. Occasionally, it becomes abundant, as for example in 1904 in the Niagara
district when many valuable shade trees were stripped of their foliage. It
derives its name from the remarkable resemblance it bears to a leafless twig.
The seed-like eggs are dropped freely on the ground where they remain for the
winter. The following summer the young green nymphs crawl up the trees to
the foliage above and begin feeding. They reach maturity after a series of moults
in September when they attain a length of 33^2 inches and are dark brown to
green in colour. After egg-laying the adults soon die. There is but one gener-
ation a season.

Control. — As the adults are very susceptible to sudden changes of
temperature, the early frosts undoubtedly play an important part in their
control. Where these insects are numerous a spray of lead arsenate, 1 to 1J/2
pounds in 40 gallons of water will control them.

34

Giant Silk Worms

(Saturniidae)

Several members of this family feed on various deciduous trees and the
caterpillars often attract attention on account of their large size. They are
seldom in sufficient numbers to be of any serious economic importance.

Among these species may be mentioned the cecropia larva, Samia cecropia
Linn., one of the largest of caterpillars, attaining the size of four inches in length.
It is green in colour with blue, yellow and red spiny protuberances on the back.
It feeds on maple, basswood, elm, birch, willow, poplar, etc.

The larva of the io moth, Automeris io Fabr., also green, has a red stripe
down each side and is studded with groups of black-tipped cactus-like spines
which are venomous. For this reason it should be handled with care. Among
the different plants it attacks are the maple, oak, elm, basswood, birch, ash
and poplar.

The polyphemus, or American silk-worm caterpillar, Telea polyphemus
Hubn., is somewhat smaller than S. cecropia. It may be recognized by the
silvery tinted breathing pores conspicuous on the sides of its green body. It
has a wide food range and will readily eat elm, maple, ash, basswood, poplar,
willow and birch.

The larva of the luna moth, Tropea luna Linn., is another general feeder.
It attracts particular attention on account of its size (three inches) and of
the beauty of the adult, rather than by any actual damage it may do. It has
been found on walnut, hickory, oak, beech, birch, willoAV and other deciduous
trees.

WOOD BORERS

The Sugar Maple Borer

(Glycobius speciosus Say)

This is a common enemy of sugar maples in Eastern Canada, and the injury
caused by the borers is often seen on the trunks. The adult, a beautiful black
and yellow beetle about an inch long, with a characteristic yellow W-shaped

mark on the back, deposits its eggs in mid-
summer in slits in the bark of the trunk,
or larger branches. The legless grubs
have powerful jaws and excavate shallow
burrows, usually slanting upwards often
several feet long, in the inner bark and sap-
wood. These tunnels more or less com-
pletely girdle and seriously weaken or kill
the infested branches or trunks. The
young grubs are betrayed in the fall by
protruding "sawdust" and the tunnels of
the larger borers produce unsightly scars.
The grub changes to the pupa and finally
to the adult beetle in the end of the tunnel,
and the beetle cuts its way out through
the bark by an oval hole about one-half
an inch in diameter. The beetles appear
in June and July to deposit their eggs for
the next brood. Apparently healthy trees
are attacked, and dying branches and
_ ,0-0,, trunks, as well as the scars referred to, are

biG. 43. — Beetle of sugar maple borer; about ., ,. - ., ,

twice natural size. (After Hutchings.) the result Ot its work.

35

Control. — Much of the injury could be averted by examining the trees in
the fall and again in the spring and cutting out the borers with a sharp knife or
killing them by a wire thrust into ,
their borings. The fresh tunnels ,

discovered should be followed with
the least cutting possible, and the
borer at the end destroyed; the
injury caused by the borers will
eventually be more serious than j
the cutting necessary to remove *
them. The scars resulting from
old tunnels should be smoothed
off, and these where necessary, '^
as well as the fresh tunnels, j|i I
should be disinfected and filled • % "H ■*

with grafting Wax Or putty. Fig. 44.— Sugar maple showing tunnel line and ugly scar,

the work of the maple borer. (After Hutchings.)

The Bronze Birch Borer

(Agrilus anxius Gory)

This insect is the most destructive enemy of white birches in many parts
of Eastern Canada. The adult is a rather slender, olive-brown beetle of metallic
lustre, nearly one-half an inch in length. The grubs which cause the injury are
slender whitish borers found excavating their tunnels in the inner bark of the
trunk and branches of infested trees. The tunnels are very elongate and wind-
ing, and eventually girdle and kill the parts attacked. Infested trees begin
to die at the top, and after a few years they gradually succumb. The location
of the larvae is often disclosed by the reddish patches on the bark caused by the
oxidizing sap flowing from the borings, but more often by the ringed swellings
on the trunk. The adults escape to the exterior through lunar holes, so char-
acteristic of this group of beetles. (See fig. 45.)

Control. — It is difficult to preserve white birches in localities where these
beetles are abundant. At the first appearance of injury the infested tops and
branches should be removed and burned before the beetles emerge from the
wood, late in May or early in June, to spread the infestation. After much of the
top has died from the attack of the beetles, it is hopeless to attempt to save the
tree by repeated prunings since the whole tree by that time is a breeding ground
for the pest, and should be cut down completely and burned, either in late fall
or early spring to prevent the spread of the beetles to other trees.

The Poplar Borer
\ ^ t m (Saperda calcarata Say)

„ «> f * | \ # Dying and dead branches and tops of

aspens and other poplars are frequently
caused by the large, yellowish-white grubs
of this species, which excavate wide burrows
deep into the trunk. Sap oozing from the
tunnels and piles of frass about the base of
the trees are indications of an attack.

The adults, long-horned beetles, 1J
inches in length, grey with yellow markings
and numerous black spots on the back, appear
in midsummer and lay their eggs on the
bark of the trunk. The grubs live for about

JbiG. 46. — Beetles of poplar borer. ,, . ,, 1 1 l • 1 ^^.+u

(After Chrystal.) three years in the wood and attain a length

of nearly two inches. The extensive bor-
ings kill much of the bark, permit the entrance of wood destroying fungi and
weaken the trunks so that they frequently break during storms. (See fig. 49.)

36

Fig. 45— Bronze Birch Borer. 1. White birch injured by borers; top dead. 2. Larval mines, with larva
in its winter cell. 3. Beetle. 4. Beginning of mine. (After Swaine.)

37

*MB&&*

*P?V

-..--■ '

%«*•" '" .

Fig. 47. — Larval mines and pupal cells of poplar bor<

(After Chrysta

Control. — Infested trees of little value should be removed and burned
before June. Valuable trees may be saved by cutting out the grubs in the early
fall, or killing the borers by injecting a small quantity of benzine or carbon
bisulphide into the tunnel's entrance by means of a machin-
ist's oil can or an atomizer, and retaining the fumes with a
plug of clay or putty. Cutting down and burning the most
heavily infested trees (brood trees) will be found most help-
ful in reducing the infestation. Painting the egg scars with f . .
creosote in October has been advocated. Some benefit may
be derived from the application of poisoned contact sprays.

The Linden Borer
(Saperda vestita Say)

Basswoods or lindens are attacked by many insects. The
larva of this species is responsible for tunnelling long irregular
galleries, particularly at the base of the tree. On young
nursery stock this form of injury is specially severe.

The adult, which appears in midsummer, also feeds on
the bark and tender, succulent parts of the leaves and
branches.

It is a buff-coloured beetle with six black spots on the
back, and is a little more than half an inch in length.

Control. — Remove all dying and sickly branches. Watch
for any attack and destroy the beetles or young grubs at once.
It is important that nursery stock be inspected systematically
several times during the season for signs of the enemy.

The Elm Borer

(Saperda tridentata Oliv.)
Dying or dead branches of elm trees sometimes show indi-
cations of injury by this borer. The adult beetle is about
half an inch long, grey with black spots and transverse red
markings. It appears in June and deposits eggs in the
bark. The grubs bore in the inner bark and sapwood for
about a year. They are found in dying branches and trunks
killed by fungi and also in living trees. The species is fig. 48.— Scars on bark
apparently more injurious in the Eastern States than in of poplar caused by
Canada. Cutting and burning badly infested trees before poplar borer.

June will help in checking the spread of the injury. (After Chrystal.)

38

The Locust Borer

(Cyllene robiniae Forst.)

The common or black locusts, or acacias, as they are sometimes called, are
frequently disfigured on the trunks by ugly scars which open into tunnels the
size of a lead pencil, cut by whitish grubs about an inch in length. The adult
is a long-horned beetle, three-fourths of an inch in length, black, marked with
transverse yellow lines, commonly found on goldenrod blossoms during Septem-
ber. The females lay their eggs singly in crevices in the bark of locust trees
during autumn. The young grubs pass the winter in the inner bark and the

<*

Fig. 49. — Poplar injured by poplar borer. (After ( bry&tal.

following spring they develop rapidly, cutting winding tunnels deep into the
wood and upward from the point of entrance, pupating about midsummer.
The progress of the injury is indicated by extruded frass, and dying sappy bark.

Control. — On valuable ornamental trees the young borers can usually be
killed by spraying the infested parts of the trunk shortly after growth coin-

39

Fig. 50.— Locust borer. 1. Eggs on bark. 2. Same enlarged. 3. Adult. 4. Hibernating larvae.
5. Larval mines. 6. Egg hatched and filled with boring dust. (After Swaine.)

40

mences in spring with one-quarter pound of sodium arsenate, or other soluble
arsenate, in five gallons of water in which one quart of miscible oil has been
mixed. The larger borers may be killed during June by means of a knife and
wire or by injecting carbon bisulphide into the borings. All badly infested and
useless trees and branches should be removed and burned before midsummer.
Where possible all goldenrod plants in the neighbourhood should be destroyed.
It is stated that locust groves planted in thick stands or grown under shade
for the first fifteen years are free from borer injury.*

The Mottled Willow Borer
(Cryptorhynchus lapathi Linn.)

This European species has become established in many parts of Eastern
North America and it is abundant in southern Ontario and southern Quebec.
It causes serious injury to poplars and willows, particularly to nursery stock,
fields of basket willow and to ornamental trees.

The adult insect is a hard-shelled snout beetle, about two-fifths of an inch
in length, covered with black and pale scales, with the hinder third of the wing-
covers pale pink in colour. The beetles appear in July and August and feed on
the young shoots, later depositing their eggs in holes which they cut into the
corky part of the older bark, frequently about scars. The young are whitish,
legless grubs; they feed on the soft tissue of the inner bark and outer wood,
passing the winter as partly grown grubs. Feeding is continued in the spring
during April and May and the dark moist frass then expelled in quantities from
the tunnels indicates that the larvae are ravenously at work. Boring proceeds
usually around the trunk or branch with the result the tree is often girdled.
When nearly full grown the grub bores upward into the wood and pupates during
midsummer, changing to the beetle which cuts its way out in July and August.
The injury is evidenced by the frass and sap exuding from the tunnels and by
the dying bark overlying the injured parts. The smaller trees are badly injured
and frequently rendered useless or killed by the borings.

Control. — The most satisfactory method of control is to coat the infested
parts with carbolineum during the first warm spring weather in late March or
early April, rubbing it in thoroughly with cotton waste. Nursery trees usually
require treatment only on the lower four or five feet of the trunk. The base of
the tree is most seriously affected and requires special attention, but the car-
bolineum should not be allowed to reach the roots. f Very badly infested trees
should be cut and burned before Mav.

The White Pine Weevil
(Pissodes strobi Peck.)

This insect is the most serious enemy of white pines in Eastern Canada.
It injures young trees from 5 to 30 feet in height by destroying the
terminal shoots, and in this way it produces a more or less serious distortion of
the trunk. It is most commonly found attacking white pine, but it occurs also
on both Norway spruce and red spruce.

The adult is a brown snout-beetle about one-fourth of an inch long, with
two whitish spots on the back behind the middle. The females place the eggs
in cavities cut in the bark, usually on the terminal shoots of young pines, in
May or June. The whitish, footless grubs eat their way into the wood towards
the heart. When the grubs are very numerous the terminal shoot is thoroughly

♦Craighead, U.S. Dept. Agric. Bull. 787.
t Matheson, Cornell University, Bull. 388.

41

riddled and dies towards midsummer. Chip-cocoons are formed at the enlarged
ends of the tunnels in which pupation occurs. The adult beetles then eat their
way out from the shoots in late summer, from about the end of July onwards to
the middle of September.

Control.- — On ornamental trees and small plantations the dying tips should
be cut off below the infested portion in June and July and left near the infested
trees in boxes or barrels securely covered with fine wire netting. This will
retain the weevils but allow the useful parasites which may be present to escape.

Fig. 51. — White pine shoot injured by white pine weevil. (After Swaine.)

The container should not be emptied till the following June, when the treatment
should be repeated if the injury is still evident. Burning the infested shoots
collected is a less desirable way of destroying the grubs.

It has been noticed that pines growing under poplar of the same age are
usually immune from weevil attack. In planting belts and blocks of white pine
this method should be tried, planting the pine and poplar alternately each way,
spaced 4 by 4 feet, with a view to removing the poplar as the trees develop.

42

The Flat-headed Apple Tree Borer

(Chrysobothris femorata Say)

This insect, though an important pest in the apple orchard, is also respon-
sible for attacking a variety of shade trees, particularly oak and mountain ash.

The beetle is about half an inch in length,
dark grey and of metallic lustre. The
eggs are laid in the summer on the bark of
the host tree, and the flat-headed, legless
grubs work through the sapwood into the
heart wood where thev hibernate.

Control. — Since the beetle appears to
have a preference for trees that are un-
healthy, it would be well to prune out and
burn all diseased and dying wood. Car-
bon bisulphide can be injected into the

Fig. 52.— Flat-headed apple tree borer life- tunnels Or the young larvae CUt Out with

^^^^*\d?l^Ai& a sharp knife and the injury creosoted.

Riley.)

The Oak Twig-pruner

(Hypermallus villosus Fab.)

This species is frequently abundant in Eastern Canada, pruning off the
twigs of oaks. It is known, also, to attack maple, hickory and locust. The
eggs are laid in midsummer on the smaller branches, and the young grubs bore
under the bark, and later into the centre of the twigs, thereby weakening them
to such an extent that they break off readily during the first wind storm and
drop to the ground.

Control. — As the fallen twigs contain the grubs they should be gathered and
burned during the autumn or early spring in order to prevent the spread of the
infestation.

The Lilac Borer
(Podosesia syringae Harris)

This is a common pest of lilacs. The injury is caused by a whitish cater-
pillar, the larva of a clear-winged moth, boring in the base of the stem. The
injur}' often takes the form of ugly scars, punctured with exit holes. The stems
are frequently girdled and killed where many larvae work together.

Control. — Valuable lilacs should be examined during the early summer and
any borers in the stems removed with a sharp knife or killed by injecting carbon
bisulphide into the tunnels, retaining the fumes for a few hours with a plug of
putty or clay. The holes should later be coated witli tar or creosote and tilled
with putty. Dying and unthrifty stems should be cut out and burned as soon
as they are discovered.

I'm;. 53.— ( Carpenter worm. (After Hut eh inns.)

43

Fig. 54. — Lesser oak carpenter
worm moths.

A. Female. B. Male.

(After Hutchings.)

The Carpenter Worm
(Prionoxystus robiniae Peck)

This borer, a large, white, or reddish-white caterpillar with a brown head,
about 23^2 inches long, is found boring in the wood of the trunks and branches of
hardwood trees. The adult female is a stout, spindle-shaped, grayish moth with
a spread of two and a half inches across its mottled wings, while the male is
somewhat smaller, very trim in outline, with the fore-wings grey and pointed
and the hind-wings bright orange in colour. The dark brown, oval eggs are
deposited in crevices of the bark, and the caterpillar bores through the bark and
sapwood deep into the heart-wood, in which it excavates large, more or less
vertical tunnels. It probably lives three years in the wood and finally changes
to a large brownish pupa which projects from the tunnel openings on the surface
before disclosing the moth. Its work results in unsightly deformities on the
trunks of the infested trees, and destructive fungi obtaining entrance through the
burrows of the caterpillar, continue the destruction. It is a serious enemy, in
Eastern Canada, to ash, maple and black locust trees and has been recorded
also from willow, poplar, oak, elm and chestnut.

Control. — The control of this insect is difficult and feasible only on valuable
trees. The best practice is to trim away the roughest portions of the deform-

Fig. 55. — Red oak log showing severe injury by carpenter worms. (After Hutchings.)

44

ities in which the caterpillars are working and then inject a sufficient amount of
carbon bisulphide with a syringe into the borings and close all the holes with
putty, clay or soap. Some of the larvae may be killed with a knife and wire.
It has been found beneficial to spray the trunks and larger branches with poisoned
kerosene emulsion during August. (See bottom page 8.)

The Lesser Oak Carpenter Worm
(Prionoxystus macmurtrei Guer.-Men.)
This species resembles, in many respects, the carpenter worm in appearance
and in habit, except that the grey wings of the female are crossed by a number
of black wavy lines, and the male moth is very small, about f-inch long, and is
clear winged. The larva bores in living trunks of red oak (Q. rubra Linn.)
seriously disfiguring and weakening or even killing trees which are badly affected.
The tunnelling is carried up into the heartwood and deep auger-like holes are
formed. (See figs. 54 and 55.)

Control. — This is the same as for the carpenter worm, given in the pre-
ceding paragraph.

The Maple Sesian
(Sesia acerni Clem.)
This species is injurious to hard and soft maples. The adult, a clear-
winged, wasp-like moth with a bright red, fan-like tuft of scales at the end of
the abdomen, deposits its eggs usually about wounds on the trunk, between May
and June, and the caterpillars are often found boring in the developing wound
tissue. Large, unsightly scars and greatly weakened trees result from their work.
Control. — Wounds resulting from any cause should be properly trimmed,
disinfected and filled with grafting wax or putty as soon as discovered. Trunks
infested with the larvae should be examined late in the season, the borers re-
moved and the wounds properly smoothed and covered
with tar or paint.

The Pitch-mass Borer
(Parharmonia pini Kellicott)

This and allied species produce large masses of pitch
on the trunks of pine and spruce. The larvae generally
attack just below a branch, or at a wound opening and
excavate winding tunnels in the sapwood. Pupation
occurs in the pitch-mass, and the pupal cases are made
to project to the exterior sufficiently to allow the moths
to escape.

Control. — When they occur on ornamental trees the
pitch-masses should be removed and the caterpillars
destroyed.

The Pitch Twig Moth
(En trio comstockiana Fernald)
The caterpillars of this moth produce rounded
masses of pitch on the branches of hard pines, usually

in the crotches of the twigs. Under the pitch-masses
are short tunnels cut by yellowish or brownish cater-
pillars about half an inch in length. They hibernate
under cover of the masses on the twigs, pupate in the
spring, and the adults, small reddish-brown moths,
appear in May and June.
Fig. 56.— Nodule produced by Control. — When necessary open the pitch-masses and

pitch-mass borer. j , , ,

(After de Gryse. I destroy the larvae.

45

The European Pine-shoot Moth
(Rhyacionia buoliana Schiff.)
This injurious species has been introduced into the Eastern States from
Europe, and has been found recently in different parts of Canada, as for example,
in southern Ontario, Nova Scotia and British Columbia. The small, brownish
caterpillars destroy many of the buds on young trees and produce a distorted
growth. It affects many species of pines in Europe and may be expected to
prove a serious enemy in pine nurseries and plantations wherever it becomes
abundant. The moths are small, reddish-yellow with silver markings; they
appear in midsummer and deposit eggs on the terminal buds. (See fig. 58.)

Fig. 57. — Caterpillars of the pine-shoot moth destroying pine buds. (After Busck.)

Control. — Suspected injuries by this insect should be at once submitted to
an entomologist for determination and every effort should be made to eradicate
an infestation. Cutting and burning infested shoots at the first sign of injury
and the destruction of heavily infested trees are the only measures that can be
recommended.

PLANT LICE OR APHIDS

Plant lice are minute, sucking insects, usually greenish or dark in colour,
frequently wingless, occurring in a great variety of species and affecting many
kinds of plants. There are usually many generations during the season, hastened
by the production of living young, so that these insects may multiply with an

46

astounding rapidity, unless held in check by natural control agencies which
include lady bird beetles, the maggots of syrphus flies, the larvae of aphis lions,
and adverse weather conditions.

During the summer winged
individuals may be produced
which fly to other species of
plants and give rise to another
series of generations, the last
of which return to the original
host. Often towards the close
of the season a sexual genera-
tion produces eggs by which the
species is carried over winter.

The feeding of some species
of plant lice distorts the plant
tissues; a few of che gall-
making aphids are mentioned
in another section.

In general, plant lice are
controlled by spraying with
contact insecticides such as
nicotine sulphate and kerosene
emulsion. (See page 8.)

The Pine Bark Aphis
(Chermes (Adelges ) pinicorticis
Fitch)
This is a common enemy of
cultivated white pines. It
appears as flocculent white
masses upon the green bark of
the trunk and branches. Like
the spruce gall aphids it is
rarely of any importance as a
forest insect, but its effect
upon the smaller isolated pines,
growing under unthrifty con-
ditions, is often serious.
The living plant lice, dark-reddish in colour, are found upon the more
tender parts of the bark sucking up the sap through their slender beaks. They
secrete an immense amount of fine white wax, which covers them and gives
the characteristic flocculent appearance to infested tret's, as though patches of
wool had been gummed on the bark. Whenever this insect becomes very
abundant, serious injury may be expected to the infested trees.

Control. — Pines growing under suitable conditions are less likely to be
seriously affected. It is, therefore, important to give the trees the best possible
conditions for growth, including sunlight and an abundance of water in dry
periods. The insects may be killed by thoroughly spraying the infested por-
tions of the bark with strong kerosene emulsion, 1 part of the stock solution
in 2 parts of water, or miscible oil at the rate of one part oil in twenty parts of
water, in the early season before the buds open. The spray will be more effective
if the insects and the flocculent covering have been previously removed in part
by a strong spray of water or by means of a stiff brush wet with very strong soap
suds. Spraying with weak kerosene emulsion or miscible oil late in May after
the young are found crawling on the bark is also recommended. When sufficient
pressure is available, thorough spraying with water from a garden hose is bene-
ficial in destroying many of the insects.

Fig. 58. — Twisted K''<>\vth of young pine trees caused by
work of the pine-shoot moth caterpillar. (After Busck.)

47

The Negundo Plant Louse
(Chaitophorus negundinis Thos.)

Enormous numbers of green plant lice occur on the foliage of Manitoba
maples, distorting the leaves and disfiguring them by a copious exudation of
honey dew on which a sooty fungus
grows abundantly.

Control. — Nicotine sulphate and
soap or kerosene emulsion should
be applied as soon as the injury is
observed.

Maple Plant Lice

Several species of plant lice may
become very abundant on hard
and soft maples. When control
measures are required, spray with
a contact insecticide such as nico-
tine sulphate.

The Elm Woolly Aphis
(Schizoneura lanigera Hausm.)

Elm leaves are often badly
curled and twisted into rosettes by
plant lice of this species. About
the first of July the insects leave
the elm leaves and live upon the
bark of neighbouring apple trees
for the remainder of the season.

Control measures for this insect
are rarely needed; although the
destruction of worthless apple

trees is advisable. Fig. 59.— Elm leaf curled by woolly aphis. (After Ross.)

The Larch Woolly Aphis

(Chermes strobilobius Kalt.)

This small woolly plant louse is frequently abundant on cultivated larches.
The trees sometimes appear as though covered with tiny snow-flakes, from the
abundance of white wool-like wax threads covering the lice feeding upon the
leaves. The injury is seldom serious, but may weaken the trees when the insects
are very abundant.

Control. — Spraying with kerosene emulsion or nicotine sulphate and soap
is an effective remedy.

The Beech Woolly Aphis

(Cryptococcus fagi Barensps.)

This destructive European species has become established in parts of Nova
Scotia and Prince Edward Island, and has apparently caused considerable
injury. The minute bark lice secrete a large amount of white, wool-like wax
threads, so that, when they are very abundant, the bark becomes coated with
a whitish, felt-like mass.

48

Control. — Thorough spraying with a strong contact insecticide (such as an
oil emulsion) in early spring, preceded, where feasible, by the removal of

much of the wool-like coating by means of a long-
handled brush, is the only remedy that can yet be
suggested.

The Balsam Twig Aphis

(Mindarus abietinus Koch.)

This minute plant louse frequently infests balsam
twigs in immense numbers early in the season
causing the needles to become badly curled and
twisted. Many twigs are killed when the insects
are very numerous; the injured twigs are always
unsightly, and a serious distortion of the trunk may
at times occur.

Control. — Spraying with kerosene emulsion, or
nicotine sulphate and soap when the trouble is first
noticed, and again as required, will hold the insects
in check on ornamental trees.

SCALE INSECTS

The Oyster-shell Scale

(Lepidosaphes ulmi Linn.)

This scale insect occurs sometimes in immense
numbers on the bark of willow, poplar, ash and other
shade trees and shrubs, and it is also a well known
enemy of fruit trees. The scales are about one-
eighth of an inch in length, and shaped like a
miniature oyster shell. The eggs over-winter be-
neath the female scales and hatch in late May and
early June into minute,
yellowish-white lice, which
distribute themselves over
the bark for a short time

and then become permanently attached thereto by

their slender sucking mouth-parts.

Control. — They may be controlled by lime sulphur

spray, commercial lime sulphur (1.035 sp. gr.), five

gallons to 35 gallons of water, or by miscible oil, one

to fifteen, applied before growth starts in the spring.

Spraying with nicotine sulphate and soap shortly after

the eggs have hatched is beneficial.

The San Jose Scale
(Aspidiotus perniciosus Comst.)
This scale insect has been very destructive in the
past to orchard trees and severely affects deciduous
shade trees and shrubs in southern Ontario. The
female insect is minute, yellow, without legs or anten-
nae, covered by a flat, circular, greyish scalo about y1-
inch in diameter, with a central dark or yellowish nip-
ple. The male scale is smaller than the female. The
insects beneath the scales feed by sucking the sap.
They multiply and spread over the bark with greal

Fig. 60. — White flocculent masses

of the woolly aphis on beech.

(Original.)

ill

( t> ster-shell scale on
ipple. (After Ross.)

49

rapidity, the young crawling about for a short time oefore fixing themselves per-
manently by a slender beak thrust into the bark and secreting the covering scale.

Control. — Control may be effected by
spraying thoroughly in the late fall or in
early spring before growth starts with
miscible oil, one to fifteen, or with the
winter strength of lime-sulphur wash, at
the rate of five gallons of commercial
lime-sulphur (1.035 sp. gr.) to thirty-
five gallons of water.

The Pine Leaf Scale

(Chionaspis pinifoliae Fitch)

The needles of pines and spruces are
frequently affected by this small, slender,
whitish scale, and when very abundant
it gives the foliage a somewhat greyish
appearance and serioufly affects the
health of the trees. Purple eggs under
the female scales hatch in June.

Control. — It is recommended to spray
with a weak contact insecticide during
the latter part of June while the young
are crawling about on the foliage. Spray-
ing in early spring before growth starts

with miscible oil in the proportion of One Fig. 62.— San Jose scale on apple; enlarged

to fifteen will clean the leaves of this pest. about seven times. (After Ross.)

The Spruce Bud-scale
(Physokermes piceae Schr.)
Several of these brownish, subglobular scales, about one-eighth of an inch in
diameter, may often be found in the axils of the twigs on unthrifty or dying

branches of cultivated spruces. The injury
is not uncommon in Eastern Canada, but
only rarely is it abundant enough to demand
treatment.

Control. — Spray the infested foliage with
nicotine sulphate late in July, while the
young are crawling on the bark.

The Goleen Oak Scale
(Aster olecanium variolosum Ratz.)

Minute, rounded, convex, golden scales,
each sunk in a small pit, are sometimes very
numerous and destructive on oak twigs in
parts of Eastern Canada. The insects suck
the sap, and when numerous seriously weak-
en the trees. The young appear in May and
early June.

Control. — A spray of kerosene emulsion,
1 to 9, applied while the unprotected young
are moving on the bark is a simple method of
control. Badly infested trees should be

Fig. 63— (a) Spruce twig infested by pine- qnrnVPf| jn parlv crm'np- bpforp thp prnwth
leaf scale, natural size; (b) male and fcPrayea .m eariy spring, Deiore tne grOWin
female scales enlarged. (After de Gryse.) starts, With miSClble Oil, One to fifteen.

50

The Black-banded Maple Scale
(Eulecanium nigrofasciatum Perg.)

The limbs of maples and other deciduous trees are sometimes severely
injured by this red and black, strongly convex scale, less than one-fifth of an
inch long, resembling a minute tortoise shell, thickly studded over the bark of
the smaller branches. The young appear in early summer and attach them-
selves to the bark by their sucking mouth-parts.

Control. — This may be obtained by an early spring application of miscible
oil, one part of oil to fifteen parts of water. On sugar maples use nicotine sulphate
while the young are crawling on the bark about the end of June. Tortoise-shell
scales of other species found on shade trees may be controlled in the same way.

The Cottony Maple Scale

(Pulvinaria vitis Linn.)

This scale insect is sometimes very abundant on maples and other deciduous
shade trees in our eastern cities. It becomes conspicuous early in June,
particularly on the under side of maple twigs, when the white, cottony egg-mass,
containing an enormous number of eggs, protrudes from beneath the female

scale. The young lice spend the summer on
the undersides of the leaves sucking the
juice through a slender beak. In the
autumn the females migrate back to the
twigs where they hibernate.

Control. — Spray with miscible oil, one to
fifteen parts of water, in spring before
growth starts. Weak contact sprays ap-
plied thoroughly once or twice while the
young are on the leaves during Jul}' are
beneficial.

The Maple Phenacoccus
(Phenacoccus acericola King)

Females of this species and their eggs
covered with an irregular cottony mass,
nearly one-fourth of an inch in diameter,
occur on the undersides of sugar maple
leaves during the summer.

Control.— That given above for the cot-
tony maple scale may be employed when
needed.

The Elm Bakk-lotjse

(Gossyparia spuria Modeer)

The females of this species are dark reel.

scale-like, bordered with white flocculent

wax, very like a fringe, about one-fourth of

an inch in length, usually arranged along

cracks or fissures in the bark of trunks and

Fid. 64.-Cottony maple scale; enlarged, ^mbs, and irregularly on the twigs They

(Original.) suck the sap t rom the bark, often killing the

0PQ

7 ««

51

infested branches and even, finally, the trees. The leaves below infested limbs
become coated with honey-dew and blackened by a fungous growth. The
young appear in late June and early July
and feed for a time on the leaves, migrat-
ing late in the season to the bark where
they pass the winter.

Control. — The infested trunks and
branches should be sprayed thoroughly
in early spring before the buds open with
miscible oil, one gallon in fifteen gallons
of water, or kerosene emulsion, one part
stock solution in three parts of water, or
one gallon of concentrated lime sulphur
in eight gallons of water.

The Scurfy Scale

(Chionaspis furfur a Fitch)

This whitish, scurfy scale frequently
coats the bark of cultivated shrubs. The
females are about one-tenth of an inch
long, oval-pointed, with a small, yellow
tip. The males are much smaller and
elongate.

Control. — This may be effected by
spraying with miscible oil, one to fifteen,
or with lime sulphur wash, in the early
spring, before the buds open.

Fig. 65. — Elm bark louse; natural size.
(Original.)

The Dogwood Scale (Chionaspis corni Cooley) occurs on ornamental
dogwoods.

GALL-MAKING INSECTS

The Spruce Gall Aphids
(Chermes (Adelges) abietis Linn.)
(Chermes (Adelges) similis Gill.)

The gall-making aphids are probably the most destructive enemies of
cultivated spruces in Eastern Canada. The injury is distinguished by conical
galls formed on the ends of the twigs during early summer. The injured twigs
usually die and when the galls become very numerous the health of the tree is
seriously affected. Ornamental trees and spruce hedges often suffer severely.

The young plant lice hibernate on the twigs below the buds. In the spring
they mature rapidly, secreting a wool-like covering, and lay many eggs. The
young lice therefrom enter the axils of the young needles on the growing shoots,
where they feed by sucking the plant juices. The gall then develops enclosing

52

Fig. 66.— Spruce gall aphid injury. (Original.)

the young lice in cavities. at the bases of the needles. These cavities open late
in the season, as the gall tissue dries, permitting the matured insects to escape.

Control. — When only a few
trees are to be dealt with the galls
can be removed by hand and
destroyed before midsummer.
Any nearby spruce trees may
serve as a continued source of
infestation unless they also are
treated. On large trees a meas-
ure of control may be obtained
by spraying the twigs thoroughly
with a strong contact spray be-
fore the buds open in the spring,
to kill the hibernating females.
Kerosene emulsion, one part stock
solution in two parts of water
may be used as a dormant spray.
Miscible oil as a dormant spray
may also prove effective, applied
at the rate of one to twenty.

The Gouty Oak Gall

(Andricus punctatus Bass.)

Red oak twigs and small limbs
are frequently affected by hard,
irregularly rounded swellings from
one to two inches in diameter,

more or less completely surrounding the twig and often coalesced to form an

elongated mass. When very abundant remove and destroy the young galls

before the adult gall-wasps emerge.

Very many species of galls of various shapes occur on oaks, but rarely cause

any serious injury. The bullet galls Yi inch in diameter, and the oak apples,

\y<± inches in diameter, are frequently

seen.

The Poplar Vagabond Gall

(Mordvilko]a vagabunda^W &\sh)

Poplar leaves developed into a flat-
tened convoluted sack about two inches
in diameter are affected by the feeding
of numerous plant lice which are found
within. The galls dry and turn brown
or black at the close of the season.
The injury is rarely very important.
Removal of the young galls from small
isolated trees should be beneficial.

The Maple Bladder Gall

(Phyllocoptes quadripes Shimer)

The upper surface of maple leaves
is sometimes covered with numerous,
minute, green, or purple, bladder-like Fiq. 67.-Poplar vagabond gall.

growths. The inj ury, caused by minute (After de Gryse.)

53

plant mites, is common, but rarely severe enough to require control measures.
The mites apparently hibernate on the twigs and spraying with miscible oil or
lime sulphur, winter strength, in the early spring for this and similar galls is
recommended when control is needed.

The Box Elder Gall Fly

(Cecidomyia negundinis Gill.)

Unsightly, elongate, fleshy galls, which more or less seriously interfere with
the proper functioning of the leaves, are sometimes extremely abundant on
Manitoba maples. This injury is caused by a minute, two-winged fly which
lays its eggs in the leaves. When the galls are opened, small maggots, the larvae
of the gall-fly, are found within.

Control. — The remedy suggested consists in picking off and destroying the
infested leaves, so far as this is possible, as soon as the galls are noticed.

The Ash Flower-gall

(Eriophyes fraxiniflora Felt)

The work of this gall-mite produces a distortion of the staminate flowers of
the white ash into irregularly branched and fringed masses which dry and
remain on the trees over
winter. The injury dis-
figures the trees, when
abundant, and is not un-
common in Eastern Can-
ada.

Control. — It has been
recommended to spray
badly infested trees with
miscible oil, one to fifteen,
in early spring before the
buds swell.

The Cockscomb Elm
Gall

(Colopha ulmicola
Fitch)

An erect wart-like
growth about one inch
long and one-quarter inch
high, which is common on
the upper surfaces of elm
leaves, is the cockscomb
elm gall, so called on ac-
count of its peculiar shape.
It is somewhat compressed
at the base, ridged on the
sides and irregularlarly
toothed on the top. At
first the gall is green in
colour when it begins to
form in May, but later turns to brown and finally to black. In due time the
plant lice which breed within the gall escape to the exterior through an orifice
on the lower side of the leaf.

Control. — This species rarely causes serious injury. On small trees it would
be feasible to remove and destroy the disfigured leaves.

Fig. 68. — Ash flower gall; natural size. (Original.)

54

PRINCIPAL SHADE TREES OF EASTERN CANADA AND
THEIR MORE IMPORTANT INSECT ENEMIES

Alder

Alder Leaf-miner

Arborvitae

Arborvitae Leaf-miner

Ash

Ash Flower-gall
Cankerworms
Carpenter Worm
Fall Web-worm
Forest Tent Caterpillar
Giant Silk Worms
Hickory Tussock Moth
Oyster-shell Scale

Balsam Fir

Balsam Twig Aphis
Fir Sawfly
Spruce Budworm

Basswood

Cankerworms

Giant Silk Worms

Linden Borer

Spiny Elm Caterpillar

Walkingstick Insect

White-marked Tussock Moth

Beech

Beech Woolly Aphis

Birch

Cankerworms
Birch Leaf Skeletonizer
Bronze Birch Borer
Forest Tent Caterpillar
Giant Silk Worms
Hickory Tussock Moth
Spiny Elm Caterpillar

Butternut

Black Walnut Caterpillar
Yellow Necked Caterpillar

Cedar — See Arborvitae

Cottonwood — See Poplar

Elm

Brown-tail Moth

Cankerworms

Carpenter Worm

Cockscomb Elm Gall

Elm Bark Louse

Elm Borer

Elm Leaf-beetle

Elm Leaf-miner

Elm Sawfly

Elm Woolly Aphis

Giant Silk Worms

Gypsy Moth

Hickory Tussock Moth

June Beetles

Spiny Elm Caterpillar

White-marked Tussock Moth

Hawthorn

American Tent Caterpillar

Hemlock

Spruce Budworm

II ichory

Black Walnut Caterpillar
Yellow Necked Caterpillar

Larch

Larch Case-bearer
Larch Sawfly
Larch Woolly Aphis

Lilac

Lilac Borer
Lilac Leaf-miner

Linden — See Basswood

Locust

( Jarpenter Worm
Locust Borer

Maph
Antlered Maple Caterpillar

Black-banded Maple Scale
Box Elder (Sail Fly
Brown-tail Moth
Carpenter Woim

55

Maple — Continued
Cottony Maple Scale
Elm Sawfly

Forest Tent Caterpillar
Giant Silk Worm
Green Maple Caterpillar
Green Striped Maple Worm
Gypsy Moth
June Beetles
Maple Bladder Gall
Maple Leaf-cutter
Maple Phenacoccus
Maple Sesian
Negundo Plant Louse
Sugar Maple Borer
Walkingstick Insect
White-marked Tussock Moth
Yellow Necked Caterpillar

Oak

Brown-tail Moth

Cankerworms

Carpenter Worm

Flab-headed Apple Tree Borer

Gypsy Moth

Golden Oak Scale

Gouty Oak Gall

June Beetles

Lesser Carpenter Worm

Oak Twig Primer

Red-humped Oak Caterpillar

Spotted Tussock Moth

Walkingstick Insect

Yellow-striped Oak Caterpillar

Pine

Abbott's Pine Sawfly
European Pine Shoot-moth
Pine Bark Aphis
Pine Leaf Scale
Pine Sawfly
Pitch-mass Borer
Pitch Twig Moth
White Pine Weevil

Poplar

Cankerworms
Carpenter Worm

Poplar — Continued

Cottonwood Leaf-beetle

Elm Sawfly

European Poplar Sawfly

Fall Webworm

Forest Tent Caterpillar

Giant Silk Worms

June Beetle

Oyster-shell Scale

Poplar Borer

Poplar Vagabond Gall

Satin Moth

Spiny Elm Caterpillar

Spotted Tussock Moth

Spotted Willow Leaf-beetle

White-marked Tussock Moth

Spruce

Fir Sawfly
Pitch-mass Borer
Spruce Bud-scale
Spruce Budworm
Spruce Gall Aphis

Walnut

Black Walnut Caterpillar
Yellow Necked Caterpillar

Willow

Brown-tail Moth

Cankerworms

Cottonwood Leaf-beetle

Elm Sawfly

Fall Webworm

Forest Tent Caterpillar

Giant Silk Worms

Gypsy Moth

June Beetles

Mottled Willow Borer

Oyster-shell Scale

Satin Moth

Spring Elm Caterpillar

Spotted Tussock Moth

White-marked Tussock Moth

Yellow Spotted Willow Slug

57

INDEX

Page

Abbott's Pine Sawfly , 27

Alder Leaf -miner , 28

American Tent Caterpillar 11

Antlered Maple Caterpillar 25

Aphids 45

Arborvitae Leaf-miner 32

Arsenate of Lead 7

Artificial Control 5

Ash Flower-Gall 53

Balsam Twig Aphis 48

Banding the Trunks 9

Barrel Pumps 6

Beech Woolly Aphis 47

Birch Leaf Skeletonizer 19

Black-banded Maple Scale 50

Black Walnut Caterpillar 24

Box Elder Gall Fly 53

Bronze Birch Borer 35

Brown-tail Moth 16

Bucket Pumps 6

Cankerworms 12, 1 3

Carpenter Worm 43

Cecropia Moth 34

Clean Culture 4

Cockscomb Elm Gall 53

Cottony Maple Scale 50

Contact Insecticides 8

Cottonwood Leaf-beetle 32

Dogwocd Scale 51

Double Action Hand Pump 6

Dusting 8

Elm Bark-louse 50

Elm Borer 37

Elm Leaf-beetle 31

Elm Leaf-miner 28

Elm Sawfly 27

Elm Woolly Aphis 47

European Pine-shoot Moth 45

European Poplar Sawfly 28

Fall Cankerworm 13

Fall Web worm 22

Fir Sawfly 28

Flat-headed Apple Tree Borer 42

Forest Tent Caterpillar 10

Gall-making Insects 51

Giant Silk Worms 34

Gypsy Moth 14

Page

Golden Oak Scale 49

Gouty Oak Gall 52

Green Maple Caterpillar , 26

Green-striped Maple Worm 25

Hand Picking 9

Hickory Tussock Moth 23

Insecticides 7

Insect Stages 4

Io Moth ! 34

June Beetles 33

Kerosene Emulsion 8

Larch Case-bearer 26

Larch Sawfly 26

Larch Woolly Aphis 47

Leaf Eating Insects 10

LeConte's Pine Sawfly 27

Lesser Carpenter Worm 44

Lilac Leaf-miner , 30

Lilac Borer 42

Linden Borer 37

Locust Borer 38

Luna Moth 34

Maple Bladder Gall 52

Maple Leaf-Cutter 11

Maple Phenacoccus 50

Maple Plant Lice 47

Maple Sesian 44

MiscibleOils 8

Mottled Willow Borer 40

Natural Control 5

Negundo Plant Louse 47

Nicotine Sulphate 8

Oak Twig-pruner 42

Oyster-shell Scale 48

Pine Bark Aphis 46

Pine Leaf Scale 49

Pitch-mass Borer 44

Pitch Twig Moth 44

Plant Lice 45

Polyphemus Moth 34

Poisoned Contact Sprays 8

Poplar Borer 35

Poplar Vagabond Gall 52

Power Sprayer 67

Pumps, Spray 6

58

INDEX— Concluded

Red-humped Oak Caterpillar.

Page
. 25

San Jose Scale 48

Satin Moth 19

Scale Insects. 48

Scurfy Scale 51

Selection and Planting 3

Soap Solutions 8

Spotted Tussock Moth 23

Spotted Willow Leaf -beetle 32

Spiny Elm Caterpillar 18

Spring Canker Worm 13

Spruce Bud-scale 49

Spruce Budworm. 25

Page

Spruce Gall Aphids 51

Stomach Poisons 7

Sugar Maple Borer 34

Treatment of Wounds.
Tree Tanglefoot

Walkingstick Insect 33

White-marked Tussock Moth 19

White Pine Weevil 40

Wood Borers 9, 34

Yellow-necked Caterpillar 24

Yellow Spotted Willow Slug 31

Yellow-striped Oak Caterpillar 25

PUBLICATIONS ON INSECTS

The following publications of the Department of Agriculture relating to
insects are available on application to the Director of Publicity, Department
of Agriculture, Ottawa: —

Pea Weevil, The C.P.L. No. 9

Lime, Arsenate of C.P.L. No.. 10

Corn Borer, The Control of the European C.P.L. No. 16

Tent Caterpillars Circular No. 1

Flea Beetles and Their Control Circular No. 2

Chinch Bug in Ontario, The Circular No. 3

Insects and Their Control, Common Garden Circular No. 9

Tussock Moth, The Habits and Control of the White-marked Circular No. 11

Boring Caterpillars which are Liable to be Mistaken for the European Corn

Borer Circular No. 14

The Control of Bark-beetle Outbreaks in British Columbia Circular No. 15

Army Worm, The Bulletin No. 9

Pear Thrips, The Bulletin No. 15

Apple Bud-Moths and Their Control in Nova Scotia Bulletin No. 16

Fruit Worms of the Apple in Nova Scotia, The Bulletin No. 17

Cleorini (Geometridae) Studies in North America Bulletin No. 18

NEW SERIES

Crop Rotation to Offset the Injury of Field Crop Insects Circular No. 2

The Date on Which it is Safe to Reseed Fields after they have been Devastated

by the Pale Western Cutworm Circular No 4

The Fruit Tree Leaf-roller and its Control in British Columbia Circular No. 10

How to Foretell Outbreaks of the Pale Western Cutworm in the Prairie Provinces Circular No. 12

The Beet Webworm Circular No. 14

The Control of Forest Tent Caterpillars in the Prairie Provinces Circular No. 19

The Walnut Caterpillar and its Control Circular No. 21

Two Insects Affecting Cane Fruits in British Columbia Circular No. 22

The Lesser Oak Carpenter Worm and its Control Circular No. 23

The European Earwig Circular No. 24

The Grasshoppers of British Columbia Circular No. 25

The Plum Curculio and its Control in Quebec Circular No. 27

The Apple Maggot and its Control in Quebec Circular No. 28

The Apple Curculio and its Control in Quebec Circular No. 36

Two Orchard Scale Insects, the San Jose Scale and the Oyster Shell Scale Circular No. 37

The European Red Mite, a Pest of Fruit Trees Circular No. 39

The Strawberry Root Weevil, with Notes on Other Insects Affecting Straw-
berries Pamphlet No. 5

The Western Wheat-stem Sawfly and its Control Pamphlet No. 6

Directions for Collecting and Preserving Insects .• .Pamphlet No. 14

The Hessian Fly in the Prairie Provinces Pamphlet No. 30

Aphids or Plant Lice Pamphlet No. 31

Root Maggots and their Control Pamphlet No. 32

Wireworm Control Pamphlet No. 33

Control of the European Apple Sucker in Nova Scotia Pamphlet No. 45

Injurious Shade Tree Insects of the Canadian Prairies Pamphlet No. 47

The Control of the Destructive Spruce Bark Beetle in Eastern Canada Pamphlet No. 48

The Satin Moth in British Columbia Pamphlet No. 50

Methods of Protection from Mosquitoes, Black-flies and Similar Pests in the

Forest Pamphlet No. 55

Insects Affecting Greenhouse Plants Bulletin No. 7

Insects Affecting Live Stock Bulletin No. 29

Grasshoppers of British Columbia 1 Bulletin No. 39

The Colorado Potato Beetle in Canada Bulletin No. 52

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