Full text of "Annual report of the State Entomologist of Montana"

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L903NO. 1 lTIN no. 51.

nONTANA

AGRICULTURAL

EXPERIMENT STATION

— OF—

THE AGRICULTURAL COLLEGE OF HONTANA.

First Annual Report of the
State Entomologist of Montana.

BOZEriAN, nONTANA, DECEriBER, 1903,

-»"-"■ "°"'- STATEPyBLICAHONSCOLLECTON

The A vant Courier Publishing Co
1904.

OCT 3 1 2007

MONTANA STATE LIBRARY

1515 E. 6th AVE.
HELENA, MONTANA 59620

riontana Agricultural Experiment Station,

Bozeman, Montana.

STATE BOARD OF EDUCATION.

Joseph K. Toole, Governor 1

James Donovan, Attorney General >ex-officio Helena

W. W. Welch, Supt. of Public Instruction )

N. W. McConnell Helena

W. M.Johnson Billings

O. P. Chisholm Bozeman

J. G. McKay Missoula

O. T. Paul Dillon

K- B. HoLTER Helena

J. M. Evans Missoula

Chas. R. Leonard Butte

EXECUTIVE BOARD.

Walter S. Hartman, President Bozeman

John Maxey, Bozeman

Pe^er Koch, Secretary Bozeman

Joseph Kountz Bozeman

E. B. Lamme Bozeman

STATION STAFF.

*Samuel FoRTiER, Ma. E Director and Irrigation Engineer

F. B. LiNFiELD, B. S. A Vice-Director and Agriculturist

F. W. Traphagen, Ph. D., F. C. S Chemist

J. W. Blankinship, Ph. D Botanist

R. A. CooLEY, B. Sc Entomologist

R. W. Fisher, B. S Assistant Horticulturist

Edmund Burke Assistant Chemist

W.J. Elliott Assistant Dairyman

*Absent on leave.

Post Office, Express and Freight Station, Bozeman.

All communications for the Experiment Station should be
addressed to the Director, Montana Experiment Station,

Bozeman, Montana.

Notice* — The Bulletins of the Station will be mailed irec to
any citizen of Montana who sends his name and address to ( nc
Station for that purpose.

Montana State Library

3 0864 1004 0518 5

THE COMMON TOAD

(See Article in this Bulletin)

Montana Experiment Station.

BULLETIN 51. DECEMBER, 1903.

INTRODUCTION.

This first Report of the State Entomologist of Montana contains
an account of a few of the most important insect pests of Montana
and in addition, a fairly complete, though condensed, manual of
insect pests. This manual is intended to put in easily accessible
form the most important information regarding a large number of
insects now in the state or liable to be introduced.

Considering the great importance of the codling moth, the
reader will perhaps expect to find an account of it in this report.
However, such an account is omitted for two reasons, first, a report
on this pest was issued from the Experiment Station a few months
ago, copies of which are still available for distribution, and, second,
it is intended to conduct further investigations on this pest during
the coming summer (1904) and we shall desire to publish those
results one year from now. In view of the fact that the codling
moth will for years to come be the most important insect pest with
which Montana apple growers will have to contend, it is our inten-
tion to make the next report upon the subject the most complete
and practical that has 3^et been issued from this Station.

In view of the great economic importance of grasshoppers
and because of the unusual demand for information concerning them,
we have given them prominence in this report.

We renew our statement of willingness to answer inquiry re-
garding insect pests. Such requests for information should always
be accompanied by specimens of the insects that are doing the
damage and a statement of the facts necessary for our information
in making recommendations.

Every vegetable product of the soil is subject to the attack in
insect life and every crop that is grown by men is more or less in-

200 MONTANA EXPERIMENT STATION.

jured by "insect pests. These injuries may be so conspicuous as to
force themselves upon our notice or they may be so hidden and in-
sidious as to escape detection except by the most observant. The
farmer may suffer heavy financial loss, or because of the higher
price which comes as a result of a shortness in the crop, he may be
only slightly affected. In the latter case the general public become
the suffers, but in all cases, losses through depredations of insects
come out of the coffers of man, if not out of his daily bread.

Considering the great agricultural possibilities of this state,
together with the fact that, incidental to commercial practices, in-
jurious insects new to this region are constantly liable to introduc;
tion, it is very important that every possible means be imployed to
prevent the introduction and spread of pests of all horticultural and
agricultural plants.

All rational means of defense against injuries from animals of
this class are based on a more or less intimate knowledge of the life
history and habits of the insects. It is apparent, therefore, that as
a defensive measure the acquiring of a knowledge of life histories of
the insect destroyers of our crops is of great practical value and
must always precede quarantine and medical work.

Again, in order that investigations may be safeguarded against
danger of becoming narrow and losing their practical setting, it is
obviously necessary that they be conducted not only in the entomolo-
gist's office or in one locality, but in the field and throughout the
state.

Realizing the truth of these statements the Entomological De-
partment of the Experiment Station is centralizing its efforts on the
accumulation of information regarding species of insects that are
now or may become injurious and, obedient to the Act of the Eighth
Legislative Assembly, whereby the office of State Entomologist was
created, is making its observations and conducting its experiments
in all parts of the state.

MONTANA EXPERIMENT STATION. 201

THE BUD nOTH.

Tmetocera ocellana Schrif.

The bud moth was first discovered in this country in 1841 in
Massachusetts and was at that time doing considerable damage. In
1869 it was pronounced the most injurious enemy of the apple
tree, next to the canker-worm, in the state of Massachusetts.
Since that time it has been spreading westward and has at times
been very destructive, notably in 1891 throughout Massachusetts,
New York and Canada and again in Michigan in 1892. It now
occurs throughout Northern United States from the Atlantic to the
Pacific ocean but is much more thoroughly distributed in the east
than in the west. It has been found as far south as Washington,
D. C.

For fully fifty years previous to the time the insect was first de-
tected in Massachusetts it was a well known and destructive species
in Europe. There can be little doubt that it was introduced into
America from Europe on young trees, intended for planting.

OCCURRENCE IN MONTANA.

While engaged in certain investigations concerning the codling
moth in Missoula in the spring of 1902 the writer's attention was
called to trees in the home orchards on Front street, Missoula, the
foliage of which showed distinct signs of injury by insects. On
examination it was found that the injury was caused by the bud
moth. The vernal form of the larva was doing rather serious
■damage on many trees. The buds, both leaf and flower, were severe-
ly injured and a large proportion of the expanding clusters of leaves
were tied together, each containing one of more nearly full-grown
larvae which were feeding voraciously. Beside occurring through-
out Missoula and in the orchards just outside of the city, the insect
is also gaining a foothold for a considerable distance up the valley
of the Bitter Root river.

IMPORTANCE OF THE PEST.
To just what extent this insect will be destructive in Montana's
climate, if it becomes generally distributed, cannot be foretold. Ex-

202 MONTANA EXPERIMENT STATION.

perience of other localities has distinctly shown that its injuries will
be more severe some years than others. For the present, at least,
Montana fruitgrowers should look upon it as a pest of first-class
importance. They should inform themselves concerning the
habits and appearance of the insect in all its stages and should
be on the lookout for it in the orchard.

Spraying does not appear to be effective in killing the larvae
Should the moth be admitted to the nurseries of the state it would
be very unfortunate not only for the nursery men but also for the
persons who purchase trees from them.

NATURAL HISTORY AND HABITS.

The larva or so-called worm spends the winter in a temporary
cocoon or hibernaculum on the trees. These hibernacula are re-
markable objects in that they so closely resemble the bark and the
felty surface of the young twigs as to be very difficult of detection
even by a trained eye. They are closely secreted in crevices around
the buds or in the depressed scars that mark the spots where leaves
were attached. They are about one-sixteenth of an inch across and
though made principally of the silken secretion that is produced from
the silk organs of the mouth of the caterpillar, they contain enough
of the surface parts of the surrounding bark to make them very in-
conspicuous.

Besides occurring on the twigs as has been described by various
authors, the writer has found them also under the scales of bark in
association with the hibernating larvae of the codling moth.

In the spring of the year at about the time the buds are swelling,
the larvae, which are dark brown with black heads, emerge from
their winter quarters and crawl to the buds. Observation is lacking
in Montana as to the precise time, compared to the opening of the
buds, that they arrive. It is probable, however, that in this respect the
habits would not vary much between here and other climates, for
Ihe same conditions of weather revive both insect and plant
life. Without much doubt, while a few larvae arrive early enough
to make it necessary for them to bore into unexpanded buds in order
to get food, the majority of them reach the buds after they have
begun to open. In both cases, alike, the larvae, which at this time

MONTANA EXPERIMENT STATION. 203

are less than a quarter ot an inch in length, go at once to the tender,
inner part of the bud, where they teed on the tender parts and do
great injury, often destroying the terminal growing portion of the
twig. If the bud be a fruit bud it likewise is destroyed, thereby
preventing the possibility of the production of fruit.

The destruction of the terminal bud prevents the further elonga-
tion of the twig and at the same time causes some lateral bud to
grow into a principal stem. While in some cases such an unatural
growth is not a disadvantage, in many cases the result is a very
undesirable shape of tree. This is particularly true of young trees
in the nursery row.

The larva soon makes use of one of the more advanced leaves
in the construction of a tubular retreat, which constitutes its home
and from which it emerges from time to time to feed. In feeding,
it draws in other leaves and fastens them together into a sort of
nest which is very characteristic of the species. Some of the
leaves become detached, but being bound to the other leaves fail to
drop to the ground, thereby making the nest all the more conspicu-
ous, because of the brown leaves among the green. A badly infest-
ed tree therefore has a decidedly unnatural appearance.

The larvae continue to feed in these nests until they reach full
growth, when they construct cocoons in which the remarkable
change from the larva to the pupa and from the pupa to the moth
is to take place. The full grown larva is a half inch in length, nearly
naked and of a brown color with glossy black head and shield just
behind the head. See plate I, (figure 7).

The cocoon is constructed, in many cases, in the tubular re-
treat occupied by the larva. The walls are thickened and the ends
closed up, thereby preventing the entrance of parasites, while the
moth lies in the defenseless pupa stage. Other cocoons are made
at any convenient place. Sometimes they occur in a fold of an
otherwise uninjured leaf.

In due time, 01 about two weeks from the time the larva
changed to a pupa, the moth appears. The pupa works its way out
of the end of the cocoon, aided by the hook on its back, and the
anterior end splits, thus setting free the moth, which crawls out,
expands and dries its wings and flies away. In Missoula the moths

204 MONTANA EXPERIMENT STATION.

appear from about the first to the twenty-fifth of July.

The moths are most active during the night, remaining quiet
during the day on the bark of the tree, which they closely mimic.
They are also found to some extent during the day in the foliage
The cage erected in Missoula in the spring of 1902 for
the purpose of facilitating the study of the habits of the
codling moth, has afforded us also an opportunity for the close study
of the bud moth. The bud moth was very abundant in this cage in
1903 and destroyed practically all the fruit buds, interfering seriously
with our investigations of the codling moth. When disturbed or
frightened the moths often flew directly away from the tree and com-
ing in contact with wire netting clung quietly to it for a few mo-
ments. In a few moments, however, they flew back to the tree. It
is plain that they did not feel safe on the netting and they would not
have been safe were it not for the fact that no birds could reach them
on the inside of the cage. In flying at such times the moth pursues
an irregular zig-zag course and comes immediately at rest on light-
ing.

It is worthy of special notice that there is a close resemblance be-
tween adults of the bud moth and of the codling moth. An experi-
enced person need have no difficulty in distinguishing between the
two if he has before him fresh specimens, but when the scales of the
wings are rubbed off as they often are in specimens captured in the
orchard, separating the two at sight is not so easily done. When
once placed on his guard, however, a trained observer is not liable
to make a mistake. On the other hand there are many less important
small moths in the orchard which the untrained observer or the per-
son who has paid little attention to insect life may mistake for both
of these orchard pests.

In a few days after emerging the moth begins to deposit eggs. We
had no difficulty in finding quantities of them in the cage at Missoula
and they were invariably on the smooth upper surface of the leaves.
Other writers have stated that the eggs are laid singly or in clusters
and on page 61 of Prof. Slingerland's bulletin on this insect (No. 107,
Corn. Univ. Agric. Exp. Sta. 1896), is given a figure of a group of
these eggs numbering about six, but our observation shows plainly
that in Montana the eggs are laid singly. We have never found

MONTANA EXPERIMENT STATION. 205

more than two together. A single Qgg is shown at plate I (figure i).
They are usually oval in outline, some being circular or nearly so,
and they measure slightly over one mm. in length, including the flat
outer rim by which they are attached to the leaf. They are trans-
lucent and almost colorless at first, but as the embryo develops the
black head and thoracic shield of the larva show through and the
outline of the curled larva may be distinctly seen. The egg shell
reflects the prismatic colors, both before and after the larva emerges.

We have above called attention to the close resemblance between
the adult of the bud moth and that of the codling moth. It is even
more difficult to distinguish between the eggs of the two species. In
size, shape and general appearance, they are very similar. They are
laid in precisely the same position on the foliage and are deposited at
the same time. They both reflect light and show irridescence alike,
and both are translucent. I know of no way to distinguish between
the two except by the difference in the character of the surface of
the shell of the egg.

The hatching of the egg takes place in from six to ten days after
being laid, and, issuing from the egg, the larva makes a hole
through the edge of the central portion and crawls forth. This cater-
pillar is greenish \n color, very small and delicate and it at once sets
about making a place of retreat and protection. Passing to the un-
der side of the leaf it constructs a very small silken tube near the
mid rib and usually towards the base of the leaf. The larva feeds
from the epidermis and middle layers of cells leaving the opposite
epidermis unbroken. The castings of the larva are built into the
tube giving it a black color. The portion of the leaf from which the
larva feeds is covered with silken threads laid down by the larva
and whenever possible a near-by leaf is drawn up and fastened to
the first leaf by the silken threads. Thus one often finds two leaves
stuck together, and, in pulling them apart, finds the little black tube
of this insect. The larva will not be seen unless forced to crawl out.

In selecting a place in which to construct a home the larva
searches for two leaves that are near enough together to be easily
brought in contact.

In the manner here indicated the larvae continues to feeduntil some
time in September, when, apparently prompted by instinct they

206 MONTANA EXPERIMENT STATION.

crawl to the twigs, spin the temporary cocoons which they occupy
during the winter months, and from which they issue in the spring
and pass to the buds as previously stated.

THE KINDS OF TREES THE BUD MOTH ATTACKS.

While this insect is best known as an apple pest, it feeds also on
pear, plum, quince, peach and cherry trees and on blackberry busheSy
in all cases feedinsf on the buds.

*J3

MEANS OF DISTRIBUTION.

The manner of hibernation of the insect makes it very easy for it
to be distributed on nursery stock, and this is doubtless the way in
which it has become so widely distributed. It may be readily dis-
tributed on scions.

The moths are capable of flying and doubtless go from tree to tree
and from orchard to orchard but they can only spread slowly in this
way.

NATURAL ENEMIES.

It is very probable that many of these insects fall a prey to the
birds that frequent the orchards. In fact it is reported that birds
sometimes eat the moths. There can be little doubt that the Ore-
gon chickadee, that is so common in the orchards searching on the
trees for food, does much good in destroying these insects. Various
other birds probably eat them in Montana.

It was very noticeable that the tree which had been inclosed in the
cage in Missoula for one year was much more seriously affected by
this insect. Birds had, of course, been excluded.

A number of parasites have been taken from the bud moth in the
United States and in Europe but just how much good they do can-
not be stated. I have reared an undetermined species from speci-
mens of this pest brought from Missoula to Bozeman for study.

METHOD OF PREVENTING ITS RAVAGES.

In the East this insect is said to be a very difficult one to control.
Just why this is so has never been fully explained, and as yet we
lack a sufficient knowledge of the habits to enable us

MONTANA EXPERIMENT STATION. 207

to state definitely the cause of the failure of remedial treatment, but
there is some reason to believe that in Montana a large majority of
the larvae arrive after the buds have opened enough to allow
them to crawl into the narrow cracks between the expanding leaves.
It is instinctive with these larvae to get out of sight as soon as pos-
sible, and once inside the opening buds with a few leaves tied to-
gether into a nest, sufficient food for the remainder of the larval life
is protected in such a wa}^ as to make it difficult, if not impossible, to
get the poison in contact with the food. **

If on arriving at the bud, the larvae finds its sufficiently open to
allow it to crawl in, in all probability very little food is taken from
the surface parts. If, on the other hand the bud is still closed, more
or less of the surface is eaten in boring to the center. If the part of
the bud through which the larvai eats its way is coated with a pois-
on, a fatal dose may be taken but at this season of the year the buds
are very rapidly swelling and a bud that is well coated one day may
two days later, on account of the expansion of the surface parts, be
so insufficiently covered as to be harmless to the larva that enters it.
As is well known to all fruit growers, some trees expand their leaves
earlier than others, and again peach buds open before most apple
buds.

Again, after the bud may be said to be fully expanded the inner
terminal growing shoot continues to put forth new leaves. These
leaves are the ones that form the food of the larvae and they expand
within the nest where they are not easily reached with a spray.

Considering how admirably the insect is protected by nature and
its own habits, its control when in its spring nest is at least un-
certain.

The problem is less perplexing when only nursery trees or trees
in a young orchard are concerned. Under such circumstances hand
picking of the nests should be very satisfactor}^ In picking the
nests, however, care should be taken not to allow the larvae to es-
cape to the ground for they would probably return to the trees. A
pail, not a basket, shold be used in gathering the nests, which should
be burned or thoroughly saturated with kereosene oil. If left in a
pile at the side of the field, the chances are that some of the larvae
would complete their development to the moth and fly to the trees.

208 MONTANA EXPERIMENT STATION.

There seems to be some promise of good results from the use of
summer sprays applied at the time the eggs are hatching. As is
indicated en a previous page, the very young larva on hatching from
the egg passes to the under side of some leaf where it spins a delicate
tube from the end of which it issues for getting its food which it
takes from the surface parts of the leaf. If this part of the leaf be
coated with a poison, the treatment should be successful. It would
be necessary to get the coating on before the larva spins its web on
the surface. The spray should be directed against the under side of
the leaves.

For this purpose we recommend the use of arsenate of lead in pre-
ference to Paris gieen on account of the much greater adhesive
quality of the former insecticide. Arsenate of lead sticks to the foli-
age through severe rain storms and when applied in the spring may
be found still adhering in the fall giving a whitish color to the leaves.
For this reason it has a particular advantage in the treatment of the
newly hatched larvae of the bud moth.

In controlling the insect we recommend the following:

(i). Pick by hand and destroy the nests on nursery and young
orchard trees.

(2). Spray thoroughly with arsenate of lead in the spring of the
year just as the buds are expanding.

3). Spray thoroughly with arsenate of lead about June 15.. Give
particular attention to coating the under surface of the foliage.

CONCLUSION.

This is a serious insect pest and one that the fruit grower would
do well to become familiar with and suppress before it takes pos-
session of his orchard.

MONTANA EXPERIMENT STATION. 209

THE 0Y5TER=SHELL BARK=LOUSE.

Lepidosaphes ulmi (Linn.)

This widely known injurious species is the only scale insect of im-
portance to the fruitgrower that, so far as is known to the writer, has
been recognized in Montana. It appears to be generally distributed
in the state, particularly west of the main divide, where in some
cases it has proved to be a serious enemy to apple trees. One orchard
of 800 trees in the Bitter Root valley is so badly infested as to show
its sickly condition at a considerable distance. Nearly every smaller
limb and twig on the greater number of the trees is thickly incrusted.

There can be little doubt that this scale insect, which was known
in Europe upward of a century ago, was imported into America on
nursery stock by the early settlers and later transferred to Mon-
tana from other parts of the United States in the same way.

FOOD PLANTS.

The oyster-shell bark-louse has been recorded on a large number
of food plants, the total number for America being about forty. The
list included, beside apple and pear, various other fruits and prac-
tically all the more important shade trees of northern United States.

Dr. Howard has suggested that eventually two species instead of
one may be found in the series in the list of food plants.

LIFE HISTORY AND HABITS.

If during the winter one of the female scales be turned over it will
be found to contain a mass of very minute yellowish-white
eggs, and in the pointed anterior end of the scale, the shrivelled
body of the female. Dr. Howard has found the eggs under each
scale to vary in number from 42 to 86.

In the New England states these eggs hatch about the first of
June, varying in different years according to the forwardness of the
season.. We have had but little opportunity to make observation on
this point in Montana, and have but one record. On June 5, 1903,
none of the eggs had hatched at Lo Lo. The young (Fig 3, c.) are
able to walk immediately after hatching, and working their way out

210

MONTANA EXPERIMENT STATION.

from under the protecting cover of the parent scale they crawl to
other parts of the twigs, principally to the young shoots which at
that time of year are tender and succulent. In rare cases they settle
on the fruit of the apple and pear.

After settling down and inserting into the bark the long thread-
like hairs through which the juices of the plant are extracted, the

Figure 2. — Oyster-shell Bark-louse- a, female scale from below
showing eggs; b, same from abovr, greatly enlarged: c, female
scales; d, male scales enlarged; e, male scales natural size.
(Howard, Yearbook, U. S. Dept. of Agr.)

insect goes through remarkable changes. From pores in the back,
principally at the hinder part of the body, a glandular secretion ap-
pears, and from it the scale is formed. The female molts or casts the
outer skin twice and the male once. The cast skins are incorporated
in the scales (See Fig. 2, b). After molting both sexes continue to
grow, the female attaining a much larger size than the male; com-

MONTANA EXPERIMENT STATION. 211

pare b. and d. of Fig. 2 The scales indicate approximately the com-
parative sizes of the insects under them. The mature male and fe-
male are very dissimilar in appearance. The male has long anter-
nae, a pair of eyes, three pairs of legs, one pair of wings and at the
end of the abdomen a long sharp-pointed organ. The female has no
antennae, eyes, legs or wings, these parts all being lost in the first
molt. When mature, the body of the female reaches to the posterior
end of the scale, but as the eggs are laid the body shrinks and be-
comes shortened and when the full number of eggs has been laid it
may be found lifeless, at the anterior end, the cavity under the scale
now being occupied with the eggs. As previously stated, in this con-
dition the insect passes the winter. The adult male and female are
shown at Fig. 3.

In the northern part of the United States there is only one annual
generation but in the South there are two.

REMEDY.

Insects of this character, covered as they are by a scale that fits
closely to the bark, are not easily killed by contact insecticides. The
most vulnerable point in their life appears to be just at the time the
young are hatching and settling on the bark. We have previously
recommended the use of kerosene emvilsion as a remedy for this
insect, in the strength of one part to nine of water. Various reports
to the effect that this treatment has not been effective in Montana,
have come to this office, but inquiry has shown that
in all these cases there is no certainty that the ap-
plication was made at the correct time. W^e can do no better
than to repeat our previous recommendation to watch closely for the
hatching of the eggs about the first of June and spray with with
kerosene to the strength above mentioned, after the young have
hatched. If, after a few days, more living lice are found the treat-
ment may be repeated.

EXPERIMENTS WITH LIME, SULPHUR AND SALT WASH

AS A REMEDY.

We take this opportunity to present the results of experiments
conducted at Lo Lo, Montana, in the early spring of 1903, for the

212

MONTANA EXPERIMENT STATION.

puropse of determining the value or non-value of the lime, sulphur
and salt wash, and certahi modifications of the wash, as a means of
destroying the eggs of this scale insect.

The experiments were conducted in the apple orchard of Mr.
Delaney. At the time, pear buds were swollen almost to the point
of expanding their first leaves and apple buds were slightly swollen.

Figure 3. Oystei'-shell Bark-louse; a. adult male; b, Coot of
same; c, young larve; d, antenna of same; e. adult female taken
from scale; a, c, e, greatly enlarged; b. d, more enlarged.
(Howard, Yearbook, U. S. Dept. of Agr.)

The trees are large and were badly infested with this insect. Seven
to nine trees were used in each experiment, each lot being sprayed
with a different mixture, but the total number of trees used consti-
tuted but a small proportion of the orchard. The spraying was done
April 21 and 22.

MONTANA EXPERIMENT STATION. 213

One lot was sprayed with the wash as follows:

Lime i pound. ',

Sulphur I pound. '

Salt I pound.

Water 4 gallons.

Lot two was sprayed with the following:

Lime i pound.

Sulphur I pound.

Water 4 gallons.

Lot three was sprayed with :

Lime j^ pound

Sulphur I pound-
Water 4 gallons.

In the fourth lot lime only was used as follows:

Lime i pound.

Water 8 gallons.

Two subsequent visits were made to the orchard, one before the
hatching of the eggs and one after, but I could not find the least
evidence of any good having been accomplished by any of the four
treatments.

214 MONTANA EXPERIMENT STATION.

APPLE LEAF=APHIS.

Aphis pomi DeG.

A few years ago practically all the accounts of plant lice on the
foliage of apple trees were written of one species, which was known
under the scientific name, Aphis tnali Linn. Dr. John B. Smith, of
Rutgers College, New Jersey, and others, had noticed that accounts
of the insects in other localities did not agree with their own observ-
ations, but not until Prof. E. Dwight Sanderson* published the results
of Jhis investigations, was it made clear that, instead of having one
apple aphis in the I nited States we have several.

We have at least two species in Montana, but one of these, the
Apple Leaf-aphis, is far more common than the other and is respon-
sible for practically all the injuries.

CHARACTER AND EXTENT OF INJURY.

No fruit pest has been more frequently inquired about in the let-
ters to this Station than has this aphis. These letters, as well as the
writer's experience in various parts of the state, show conclusively
that the species are very troublesome and at times a very injurious
pest. It is universally felt that as a rule young trees are much more
susceptible to attack than trees in bearing. The writer's field notes re-
cord one notable exception to this in the case of a large orchard in
Flathead county, composed of trees which had been in bearing for
many years, which were so badly infested as to have the foliage with-
ered, and the fruit undersized and poor.

A prominent characteristic of the work of the aphis is the curling
of the leaves. In this respect there is a marked difference between
the efifect on the tree of the work of this species and of "Fitche's
apple aphis," which, on the whole, is more common in the L^nited
States. In curling, the deformed leave usually takes a characteristic
shape. The surface becomes irregularly raised and the whole leaf curls
bringing the under surface inside and the upper surface exposed. The
tip of the leaf rests upon its base, not in the middle, but to one side

♦Thirteenth Auuual Report of the Deleware College Agricultural Experiment Station.

MONTANA EXPERIMENT STATION.

215

Figure 4. Wingless viviparouB female on left: oviparous female on right —
greatly enlarged. (Sanderson, 13 Ann. Kept. X. J. Exp. Station).

or the other of the mid-rib. The lice live inside of the curled leaf, a
fact which has much to do with the difficulty in controlling them
with insecticidal spiays.

There is some reason to believe that the presence of the lice in
large numbers on a tree has the effect of keeping the sap in the
tree late in the fall, thereby making it more liable to injury by
cold weather. It 's certain that badly infested leaves on the ends of
the new growth often fail to mature and remain on the tree through-
out the winter. This is often noticeable on trees in the nursery row.

The general injurious effect of the lice is to check the normal
growth of the tree. This office has many records of this effect in a
serious degree.

We have never found this louse occurring in great numbers on the
3'oung buds in the spring as is often the case with ''Fitche's apple
aphis." As a rule, only a few scattering lice are to be found
early in the season, and our exeprience has shown that frequently
only here and there a tree will be found infested in the spring of the
year, though as the season progresses the lice will gradually spread
throughout the orchard.

216

MONTANA EXPERIMENT STATION.

DESCRIPTION AND LIFE HISTORY.

Like many other plant lice, the apple-aphis passes the winter in
the egg state. In the spring the eggs hatch, producing very minute,
dark greenish lice which may be found crawling- about over the sur-
face of the bark or closely nestled on the young buds and expanding
leaves.

The spring of 1902 was looked upon as being very cold and back-
ward in the Gallatin valley, and the writer was much surprised in
going into the Station orchard on April i6tli to find an abundance of
newly hatched lice. The buds had not started and were no more
swollen than they were the fall before. There had been a few days
of hot weather which had caused the lice to hatch, but had not been
of long enough duration to start the buds. Part of the lice had been
feeding and had distinctly increased in size.

On April 19 a cold storm came and on the 20th there were about
three inches of snow. For the next few days the writer was out of
town, but on May i the trees were examined and the lice were found
to have been nearly all killed. Only two living ones could be found
and many dead bodies were still attached to the twigs. Since that

Figure 5. Winged viviparous female greatly enlarged.
Exp, Station.

(Sanderson, 13th Ann. Rept. N. J.

MONTANA EXPERIMENT STATION. 217

time, we have observed a similar, though less extensive, early hatch-
ing and killing of the lice.

If not destroyed by natural enemies or climatic conditions, the
young lice in due time become mature and begin to produce young.
Dr. Smith of New Jersey* found that about fifteen days were requir-
ed for the first generation to reach maturit}^ after hatching. The lice
are known as the "Stem mothers," (See Fig. 4, b). They are wing-
less and are greenish in color. No males are produced from the eggs
and the stem mothers are able to produce young without them.

The young of the second generation (offspring of the stem moth-
ers) are produced alive — not hatched from eggs — and are able to
begin feeding almost immediately. They settle down near the moth-
er and one may often find a stem mother with her large family close
by her. Our office notes show that the stem mother gives birth to
young at the rate of from one to fourteen per day, and that she con-
tinues day after day for fully eighteen days, producing an average

Figure 6, Male of the oviparous
generation greatly enlarged. (Sander-
son 14th Ann. Rept. N. J. Exp.
Station.

number of about six or seven. Thus each stem mother produces
fully loo young.

*Bulletin 143 of the N. J. Experiment Station.

218 MONTANA EXPERIMENT STATION.

Dr. Smith found that the second generation matures in nine or ten
days and that of chis series about three-fourths are winged ; that the
third series matures in about two weeks, less than one-half being
winged and that thereafter no more winged forms appear but that
seven series of parthenogenetic females in all appear before the end
of the season. The 8th and last series is made up of males and females.
Late in October, after the mating of the sexes, the females deposit
the eggs which remain on the trees during the winter. Figure 4,
right hand figure, shows an oviparous female. Figure 6, a male of
the oviparous generation.

A part or all of the winged individuals of the early generations fly
to other trees. A winged parthenogenetic female is shown at Fig. 5.

The eggs are minute, glossy black objects, oval in shape. They
may be found on any part of the tree from the base of the trunk to the
tips of the twigs, and are usually more abundant in the crevices of
the bark and around the buds than on the exposed, smootji surfaces.

A very large proportion of the eggs, probably upward of 90 per
cent, failed to hatch during the three years that we had the"
species under special study.

NATURAL ENEMIES. -

Of the various ratural enemies that feed upon the plant louse„

none is of greater value than the Fire-marked Lady-bug {Hyperas-

pis5-signata). Next in importance are certain species of syrphus

flies. Besides these we have observed a Braconid parasite, a small

fly that has not yet been named and the "Aphis Lion."

After two years of close observation of the babits of this lady-
bug we are prepared to say that it is a very prominent factor in the
prevention of the aphis from becoming exceedingly abundant rwI
destructive. During the latter part of May and in June the beetles
were found in great numbers in the Experiment Station orchard, and
in various other orchards, running rapidly over the limbs and twigs,
in search for the young aphids. The number they eat when in con-
finements is astonishing.

In a previous paragraph we have called attention to the fact that
only a comparatively small number of stem mothers are to be found

MONTANA EXPbRIMENT STATION.

219

early in the season and that the large numbers to be found later in
the season is the result of the rapid multiplication. It is apparent,

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therefore, that the comparatively small number of lice that the bee-
tles eat early in the season must have a great effect in the abundance
of the lice later in the season.

Though the larvae of this lady-bug eat large numbers of the lice
later in the season when they have become very abundant, we look
upon the work that they do as being of much less value than that of
the adults.

^220

MONTANA EXPERIMENT STATION

The Surphus fly larvae are probably of greater usefulness than the
larvae of the lady-bug since they are usually more abundant, but like
the beetle larvae, they do not appear on the scene until the lice have
become abundant and are multiplying with such rapidity that it
:would require a large number of destroyers to dispose of the increase
alone. Figure 8 illustrates a common species of lady-bug of the
East, while at Figure 2, plate i, is shown an adult of the species here
discussed. Figures 3 and 4 of the same plate show the eggs of the
same species and at Figure 5 is shown a full grown larva.

Figure 8, The Two Spotted Lady Bug; a. larva; b, mouth parts of same; c, claw of same;
d, pupa; e, adult; f, antenna — all enlarged. (Marlott Circular 7, Sec. Series, Division of Ento-
mology U, S. Dept. Agr.)

REMEDIES FOR APPLE LEAF-APHIS.

In spraying for this aphis we would emphasize the importance of
.watching for the individual infested trees here and there in the orch-
ard and treating them before the lice spread to the other trees. In
other words, the spraying for the apple leaf-aphis should be done and
out of the way early in the season, for under ordinary circumstances,
when vigorously fought early in the summer, though some lice es-
cape, there will be so few left that the natural enemies will be able
to keep them from overrunning the orchard.

The value of prompt treatment is apparent when : we
fealize the enormous power of multiplication with which
nature has endowed these insects. In a previous para-

MONTANA EXPERIMENT STATION. 221

graph we have shown that the stem mother's maxi-
mum power of production is upward of lOO young, and i^
is probable that later generations can give birth to a similar number.
Acting on the basis that all of the young of each generation come
to maturity and produce the full unmber of young, we find that the
progeny of one stem mother during one summer is something enor-
mous.

1st generation i aphis.

2nd generation lOO aphids.

3rd generation 10,000 aphids.

4th generation 1,000,000 aphids.

5th generation 100,000,000 aphids.

6th generation 10,000,000,000 aphids.

7th generation 1,000,000,000,000 aphids.

Thus starting with one aphis in the spring we would have in the
seventh generation one trillion aphids, a number which the human
mind cannot appreciate. Under natural conditions, however, the in-
sects are decreased in number from one cause and another, all thro'
the season, so that, while they increase very rapidly, they never do
so to the extent above indicated. At the same time, however, it is
easily seen that the destruction of a large proportion of the first and
second generations will very markedly affect the numbers through-
out the season. There seems to be little doubt that the killing of
the first generation, by inclement weather in some seasons and the
absence of storms in other seasons account for tha great variation
in abundance and destructiveness of this louse in different seasons.

Because of the great difficulty in controlling the insect after the
leaves of the trees have become curled, the writer has undertaken
to learn if it is feasible to destroy it in other ways. An extensive
seri.-s of experiments in fumigation with the deadly hydro-
cyanic acid gas was conducted. In these experiments wo
used a large canvas tent, a large paper box and a s'-iall
air-tight wooden box constructed for such work. We will
not at this time give the detailed results of these ex-
periments but will indicate the lessons they taught. Detailed instruc-
tions for the use of this substance will be found on another page of
this report. (See index.)

222 MONTANA EXPERIMENT STATION.

We found that every aphis could be killed without the least injury
to the foliage. Even though the experiments were conducted in
both cloudy and bright, hot weather, not a leaf was injured in the
whole series of tests.

We used the cyanide in strengths varying from o.io grams per
cubic foot of inclosed space up to 0.30 grams and while o.io gram
killed practically all the lice, and, on the other hand, 0.30 did not
h'jure we decided upon 0.20 gram per cubic foot as being the suit-
able amount to use in practical work.

The time of exposure was 20 minutes.

Considering the fact that by a timely and persistent use of sprays
and washes the aphis may be brought under control, I very much
doubt if this treatment should be considered as a suitable remedy
except in the case of very large owners or in company orchards
where the expense of providing a complete fumigation outfit would
be justified. Having the equipment already at hand it would cost
about 4^/2 cents per tree to treat a large orchard.

Information rgarding fumigation boxes suitable for such work as
this may be obtained from Professor Johnson's work on fumigation
published by the Orange Judd Publishing Co., New York.

We also undertook a series of experiments with the use of the
lime-sulphur and salt wash as means of destroying the egg during
the winter. We sprayed a series of trees with this wash and
modifications of it in the Experiment Station orchard and at Lo
Lo. Subsequent examinations of the trees at Bozeman showed
that while none of the eggs hatched on the trees that were sprayed
they also failed to hatch on all the other trees in the same part of
the orchard that had not been sprayed. We therefore felt that the
experiment had taught us nothing. The Lo Lo experiment also
failed to be of value for the same reason.

During the past few days a ])ulletin from the Idaho Experiment
Station, written by Profifessor Aldrich (Buletin No. 40) entitled
"Winter Spraying for Aphis Eggs" has come to my desk. The
bulletin gives in detail Prof. Aldrich's experience in the use of seven
diflferent sprays used in the winter treatment of eggs of this aphis.
The seven sprays are the following:

I. Pure kerosene.

MONTANA EXPERIMENT STATION. 223

2. Kerosene emulsion, one-third kerosene.

3. Kerosene emulsion, one-fifth kerosene.

4. Sulphur and lime wash, 1-1-2. (One pound sulphur, one pound
lime, two gallons water.)

5. Sulphur and lime, 1-1-4.

6. Sulphur and lime, 1-1-8.

7. Crude petroleum emulsion, 10 per cent, strength.

From the results of his experiments Prof. Aldrich drew the fol-
lowing conclusions :

"Crude petroleum could not be uniformly applied. The emulsion
was very unstable, and the oil is much too thick to apply pure. No
damage resulted to Ihe trees, but in many cases the eggs of lice
were not destroyed.

Pure kerosene seriously injured the trees to which it was applied,
but killed all the eggs.

Kerosene emulsion of one-third strengtli injured the foliage to
some extent, though not very" seriously'; it did not kill the eggs with
any uniformity. In one-fifth strength it did not injure the foliage,
but was not ot all effective in killing the eggs.

Sulphur and lime did not injure the foliage in the least, however
strong. In the 1-1-2 and 1-1-4 proportions it killed almost all the
eggs; it is a question whether the very few that hatched had not
been missed by the spray.

Of the seven kinds of spray used, the choice for commercial pur-
poses would undoubtedly be No. 5, sulphur and lime in the 1-1-4 pro-
portion, or what is called the "Piper formula."

1-1-4 proportion is probably a successful winter treatment, it will be
applicable only on small trees that can be closely examined and thor-
oughly sprayed.

In conclusion, we recommend that Montana apple growers make
careful, conclusive tests of the 1-1-4 lime-sulphur wash as a winter
treatment, and mean while place their main dependence on the use
of kerosene emulsion and whale-oil soap or quassia-whale oil soap
solution, spraying trees that are generally infested and dipping the

Jie further concluded that while the lime-sulphur wash in the
extremeties of limbs that are infested only at the ends of
the branches.

Formulae for these washes are given on a later page. (See index.)

224 MONTANA EXPERIMENT STATION.

THE FLAT=HEADED APPLE=TREE BORER.

Chrysohothris femorata Fab.

One of tlie most troublesome insect pests with which the Mon-
tana fruit-grower has to contend, is an apple-tree borer, which in the
larval stage is expanded and flattened near the anterior end, as shown
in figure 9, a, an appearance which has led to its being called "the
flat-headed borer." Besides attacking the apple, the borer has been
recorded also on various other deciduous trees, among which are
pear, peach, oak, maple, mountain ash, box-elder, hickory, chestnut,
sycamore, horse chestnut, redbud and currant. Mr. F. H. Chittenden
of the U. S. Dept. of Agriculture, from whose circular, (Circ. 32,
Division of Entomology) many of the facts in this paper are taken,
states that cherry, beach and white birch are probably food plants,
while an unknown authority has stated that elm, tulip, and cotton-
wood are also host-plants.

Although not considered to be a pest of first class importance
this species has been doing a great deal of damage in this state, par-
ticularly in the Bitter Root valley, and there is an increasing demand
for information concerning its habits and the means of controlling
it. It has been particularly destructive on young orchard trees, gird-
ling the trunk near the ground and killing the trees. The accompany-
ing photograph (see Plate III, Figure 7) shows the manner in which
many trees have been affected and killed in Montana. The only ex-
planation the writer has to offer as to the cause for the rather unus-
ual numbers of this insect, is that under the climatic conditions in
Montana trees seem to be affected to a considerable extent with sun-
scald, an affection which leaves the trees in an inviting and favorable
condition for this insect. It has long been known that this insect
prefers for a breeding place trees that have been previously weakened
by some other cause. Observation has shown that trees which
have been injured on the side exposed to the winter's sun are often
selected by the adult in depositing their eggs.

Young trees are affected principally on the main stem close to
the ground, but on old trees the borers work on any part of the tree
except the smaller limbs and branches.

MONTANA EXPERIMENT STATION.

225

Like other members of the same family of beetles (Biiprestidae)
the adults are diurnal in habits and are most active during the heat
of the day. By a close search in an infested orchard during the sea-
son of the year wheii the adults are out, one may find them basking in
the sun on the trunks of the trees and on prostrate logs.

DISTRIBUTION AND OCCURRENCE IN MONTANA

The flat-headed apple-tree borer is a native of North America
insect. In spite of this fact, however, we believe that it is an in-
troduced species in Montana. None of its principal food plants, so
far as known, are native to the state, or if present, occur only spar-
ingly, and moreover, its presence has been detected only in restrict-
ed localities. We think it much more probable that the insect was
brought into the state on some of the earliest shipments of trees
from the older apple growing regions.

It is a widely distributed pest throughout the United States
east of the Rocky I\Iountains, and in southern Canada.

Figure 9. Flat-headed Apple-tree Borer,
a, larva; b, beetle; c, head of male; d, pupa
— twice natural size. (Chittenden, Circular
32, Sec, Series, Div, of Entomology U. S.
Dept. of Agr.)

LIFE HISTORY.

The eggs, which are pale brown and about one-eighth of an inch
long, are laid on the trees during the hot summer months. One ob-
server. Dr. Riley, found them being laid from June to September,
but our observations in Montana indicate that while a few beetles
may be found on the trees later in the season the majority are out and

226 MONTANA EXPERIMENT STATION.

depositing their eggs late in June, and early in July. In about three
weeks^the eggs hatch and the young larvae bore under the bark,
where they feed for three years, first just vmder the bark and later
in the woody parts of the stem. On young trees they most common-
ly occur at about the surface of the ground as shown in the photo-
graph above referred to. The location of the burrow may often be
detected from the outside by the discoloration or slightly sunken
condition of the bark.

At the end of three years from the time the egg was deposited
the beetle bores out from the pupal chamber which it constructed
at the end of its larval life. The sexes mate and the eggs are de-
posited for the new generation.

NATURAL ENEMIES.

The downy wood-pecker which is so common in Montana and
which is so often seen in our orchards, is the fruit-grower's friend.
Besides picking up miscellaneous pests it locates burrows of this
borer and extracts them in considerable numbers. In the older
orchards of Montana scarcely a tree can be found that does not bear
the marks of wood-peckers, a large proportion of which are made by
this species.

METHODS OF CONTROL.

Borers as a class of pests are difficult to control. When once
in a tree they cannot be reached with an insecticide. They may in
many cases be removed by means of a sharp knife and a wire but
their presence is not usually detected until a large part of the dam-
age has been accomplished, and the injury done to the tree in re-
moving the larvae may be greater than would be done if they
were left to do their worst. It has been found, therefore, that clean,
strong, cultural methods and the use of deterrent application on the
trees, both of which are preventatives, constitute the best means of
control.

In the first place, in planting out a young orchard the trees
should not be allowed to become weakened and so rendered liable
to attack. Young trees in an exposed position should be protected
against the strong rays of the winter's sun. The alternate thawing
and freezing on the exposed side of the trunk produces the condition

MONTANA EXPERIMENT STATION. 227

known to all as sun-scald, and makes typical conditions for the bor-
ers. Dead or worthless trees should not be allowed to stand and
become a menace to the healthy ones. It is a bad practice to have
a brush pile made up of dead trees and prunings at the side of the
field. Such piles should be burnt very frequently, for they soon
become nurseries of pests.

In a locality known to be infested with this borer it is often de-
sirable to use deterrent applications on the trunks and larger limbs
of both weakened and healthy trees. For this purpose, a number of
substances: have been recommended. Some use old newspapers as
mechanical barriers placed about the base of the tree.

Mr. Chittenden recommends that these papers be put on the
trunk for about two feet from the ground up, and that above the pa-
per a carbolated or alg^iline wash be applied. Wire netting is some-
times used.

The paper and netting not only prevent the deposition of eggs
but also prevent the escape of the beetles that emerge underneath
them.

Among the substances that may be used as washes to make the
surface of the trees objectionable to the adult beetles and so prevent
them from depositing their eggs are the following:

I. A thick solution of whale-oil soap.

2.' Soft soap rendered thick by the addition of caustic soda or
potash in solution.

3. Either of the above washes would probably be made more
effective by the addition of crude carbolic acid at the rate of one
pint to ten gallons of the wash.

James Good, 939 and 941 North Front Sstreet, Philadelphia, Pa.,
offers for sale a product known as Caustic Potash Whale-oil Soap-,
which of itself would be a good substance for this purpose. It
should be diluted with sufficient water to make a thick fluent mass,
and applied to the trunk and limbs of the trees to be protected.
Such washes when not of a quality that makes them injurious to the
liands, are sometimes applied by a man wearing old mittens or socks
that are saturated with the wash.

228 MONTANA EXPERIMENT STATION.

THE PEAR=LEAF BLISTER MITE.

{Phytoptus pyri Scheuten.)

Though probably of European origin the pear-leaf blister-mite
is now widely disseminated throughout the world, having been dis-
tributed by the agency of traffic in nursery stock. It is sparingly dis-
tributed in Montana, but where well established is a troublesome
pest.

NATURE OF INJURY.

As the leaf-buds of affected trees unfold in the spring there may
be seen red blister-like spots and blotches which in severe cases may
involve practically all the surface of the leaf. At first the galls are
more distinctly seen on the upper surface of tl^ leaves but later in the
season the spots turn brown, owing to the death of the tissues com-
prising the blisters, when the affected spots become more apparent
on the under side of the leaves. The blotches often take the shape
of elongated patches one on each side of the midrib.

In each blister, on the under side of the leaf, may be seen one
or more minute holes that lead to the cavity of the blister and usu-
ally visible only under a lense or microscope.

Within these blisters composed of abnormal plant tissues, the
mites live, feeding on the juices of the plant. Under the shelter of
these galls they are very well protected, not only from wind and rain
which might easily sweep them off, but also against insecticidal
treatment. The tissues on the inside of the galls also furnish better
facility for the mites to acquire nourishment than would the thicker
layers of cells on the surface. The freshly formed galls are thick and
succulent, but as they die and turn brown they shrivel and dr3\
Badly affected trees lose their foliage long before the normal time
which must be an injury to the health of the tree.

THE MITE.

The mites that produce these galls are very minute, being
scarcely visible to the naked eye. Under a high power microscope,
the body is seen to be elongated in form, about four times as long
as wide, and has the appearance on the surface of being made up of

MONTANA EXPERIMENT STATION. 229

a large number of fine rings. There are four legs, all of which are
placed at the anterior end of the body and though small they enable
the mite to move rapidly. The head is made up chiefly of a conical
snout within which are two lance-like jaws.- To cover a linear inch
about 150 mites placed end to end would be required.

LIFE HISTORY.

From the eggs which are laid in the galls by the parent mites
the young hatch, and, crawling out of the hole, go in search of an
uninjured spot in the leaf. Then, boring through the surface they
start new galls. The mites remain in the galls until the end of the
season when they crawl to the buds and seek shelter for the winter
under the scales.

Some mites remain on the leaves too long and are borne to the
ground when the leaves fall.

MEANS OF DISTRIBUTION.

Of itself the mite cannot travel far. For distant dissemination
it is dependent upon outside agencies and has doubtless been spread
from country to country on nursery stock. From tree to tree in the
same vicinity they may be carried on the feet of the birds, or blown
by the wind on the leaves in the fall of the year.

REMEDIES.

The only vulnerable point in the life cycle of this mite is when
it is secreted under the bud scales after the leaves have fallen. Prof.
M. V. Slingerland found that the mite "can be nearly exterminated
in a badly infested orchard by a single thorough spraying of the
trees in winter with kerosene emulsion diluted with five to seven
parts of water." In all cases of treatment with a spray or winter
wash, we recommend that no twigs or branches that have been
pruned ofif be left on the ground.

We recommend that the leaves from infested trees be gathered
and burned and not allowed to blow about.

Having learned from various fruit-growers of the state that they
had not found the kerosene emulsion treatment to be satisfactory.

230 MONTANA EXPERIMENT STATION.

the writer undertook a series of tests e^ the lime-sulphur-salt wash
as a remedy. The experiments were conducted in the orchard of
Mr. C. M. Allen of Lo Lo. I would here express my gratitude to
this gentleman for many courtesies extended to me, both in connec-
tion with these experiments and at other times.

In the experiments Mr. Allen's entire orchard of 190 trees was
used and we feel entire confidence in the results we obtained. The
spraying was done on April 21 and 22, the pear buds being swollen
almost to the point of opening.

In the various tests we used the following:

Spray No. i.

Lime i pound.

Sulphur I pound.

Salt I pound.

Water 4 gallons.

Spray No. 2.

Lime i pound.

Sulphur I pound.

Water 4 gallons.

Spray No. 3.

Lime Yz pound.

Sulphur I pound.

Water 4 gallons.

Spray No. 4.

Lime i pound.

Water 8 gallons.

Ten trees were used in experiment No. 4 (lime and water only)
and ten trees were left unsprayed. The remaining trees were about
evenly divided in experiments Nos. i, 2, and 3.

The results of the tests were very satisfactory and seemed con-
clusive. The mites were practically exterminated on all trees treat-
ed with sprays i, 2, and 3. The mites on the ten trees sprayed with
No. 4 were, so far as we could determine, wholly uninjured. These
trees and the ten left unsprayed were badly affected with the mites
after the foliage expanded.

Directly the other side of a barbed wire fence are more pear
trees'badly affected with the mite. The two pear orchards are really

MONTANA EXPERIMENT STATION. 231

but one, since Mr. Allen's orchard was purchased and fenced oft*
from the other larger one, the fence, in fact, passing diagonally-
through one row. The trees on the other side of the fence were
badly infested the following summer, thus giving us greater con-
fidence in the efficiency of our treatment.

It appears that all of the first three sprays were equally effective
Spray No. 3 ^-1-4 contains only enough lime to cause the sul-
phur to go into solution, thereby making the caustic ingredient of
the mixture. The spray when ready to apply is clear and transparent
instead of milky as is No. 2, which has an excess of lime. In spray
No. I, the excess of lime goes onto the tree merely as a whitewash.
We are not prepared to say that there is not some benefit in having
this excess of lime, and for the present we recommend the use of
spray No. 2. We do not feel that the addition of salt in spray No. i
renders the wash of any more value.

In conclusion, we recommend, as a means of holding this mite
in control, a thorough spraying with lime-sulphur-salt wash in the
1-1-4 proportion, in the spring of the year before the buds open.
Directions for the pieparation of this wash will be found on another
page of this report. (See index.)

i32 MONTANA EXPERIMENT STATION.

GRASSHOPPERS.

During the past three years a considerable amount of damage
was done by grasshoppers in eastern Montana. An extensive territory
was more or less affected, in some localities the grasshoppers being'
so abundant that there was no vegetation left. From this extreme
there was every gradation down to no injury. During these three
years the grasshoppers steadily increased and the seriously affected
territory was extended.

The injuries have been principally confined to the fenced and
open ranges used by the stockmen in grazing cattle, sheep and horses,
but some damage was done to grains, cultivated grasses and alfalfa.
We received reports also of damage to fruit trees and to garden
crops.

Coincidental with the appearance of the grasshoppers has been
a series of years in which the rain and snowfall has been much below
the average. Aside from any direct or indirect influence which this
scarcity of moisture may have had on the unusual increase of grass-
hoppers, it certainly very much shortened the crop of grass. While
the amount of grass that the grasshoppers ate would have been
missed even if there had been a full growth, it is certain that what
they took was more seriously missed on account of the scarcity of
grass. ^

Roughly speaking, the territory injured through the combined
effects of dry weathei and grasshoppers may be said to be embraced
in that part of Montana drained by the Yellowstone river east of the
town of Big Timber. Not only were the valleys of the tributaries
of the Yellowstone affected but the cross country as well. We also
received reports of injury in other scattering localities. One report
came through Townsend from the country northeast of that town
and we were notified of injury on the range in the eastern part of
Madison county.

One species, the yellow-winged locust, was very abundant in re-
stricted localities in and about the Gallatin valley. We also noted

the big-headed grasshopper to be more abundant than in previous
years and in two instances the yellow-striped locust was found in
great numbers in the edges of this valley.

MONTANA EXPERIMENT STATION. 233

INJURY NOT CAUSED BY THE ROCKY MOUNTAIN

LOCUST.

Many persons have supposed the "old-fashioned" or Rocky
Mountain Migratory Locust to be responsible for the losses in Mon-
tana. Our investigations of the*subject, however, show that no one
species is alone the cause of the loss and the above species {Melan-
oplus spretus Uhler) if present in the state at all is very rare. Dur-
ing the five summers that I have been collecting in all parts of Mon-
tana I have not captured a single example of this interesting species.
Moreover, I learn by letter from Prof. Gillette of Colorado that he
has had a similar experience, having been unable to find any speci-
mens during a longei period in his state.

In our various trips into the worst affected regions we found
a fairly imiform state of affairs throughout. On the range two or
three species, taken together, constitute a large proportion of the
total number, though in restricted localities one or another species
besides these was more abundant. The three most common species
on the range were the Big-headed locust, {Aulocara elliotti), the
Lesser Migratory locust {Melanoplus atlanis) and the Yellow-
winged locust {Camnala pellucida). In point of abundance the Big-
headed grasshopper was the leading species of the three. The Less-
er Migratory Locust was second in importance. It prefers the dryer
uplands to the irrigated valleys, but in many cases it was found in
great abundance in grain fields, particularly on the benches and in
non-irrigated fields.

The Yellow- winged Locust is more local in its distribution,
often occurring in immense numbers in restricted localities and at
times becoming very injurious to grasses and grains.

We found the two-striped locusts to be common in practically
all the cultivated fields that were injured by grasshoppers. This
species was particularly injurious to alfalfa, the succulent stems and
leaves of this plant apparently suiting its taste.

LIFE HISTORY.

All our particularly injurious species are alike in the main fea-
tures of their life history. The winter is passed in the tgg stage in

234 MONTANA EXPERIMENT STATION.

the ground. The eggs are about one-fifth of an inch in length and
are deposited in compact masses or "pods" which are arranged ver-
tically, or slightly inclined, just below the surface of the ground.

In making the hole in the ground to receive the eggs, the female
makes use of special organs at the extremety of the abdomen. Plac-
ing the point of the abdomen against the ground the pointed organs
work rapidly back and forth and as the hole is made the abdomen
settles into the earth. When the hole is completed it is filled with
the mass of eggs and a viscid frothy substance.

Prof. C. V. Riley's classic illustration of the process of egg-
laying of the Rocky Mountain Locust, together with his description
of the process, show that in that species the eggs are laid in four re-
gularly parallel rows and that the number of eggs varies between
20 and 35. He also found that two or three such egg-masses were
deposited by each female insect.

The two-striped locust lays a larger number of eggs than this
for we have counted as high as 62, in a mass, and two or three masses
are deposited. The Big-headed Locust (Aulocara elliotti) probably]
deposits only two masses.

In general the places most chosen by the females for the pur-
poses of egg-laying are those at which the soil is fairly free from
grass-roots, or other roots that would interfere with boring the
holes. Such places are found on the sides of roads, in abandoned
roads, among tall weeds, etc. When the mating season comes the
adults of a species gather into colonies where they stay for the re-
mainder of their life. As a result, the young are often found in the
spring of the year in more or less restricted localities.

In our investigations of the outbreak of grasshoppers in Mon-
tana in 1903 we fornd that the Big-headed grasshopper paid little
attention to where the eggs were laid; for miles and miles over the
denuded ranges the females could be found performing this act.

In the spring ot the year, in some species earlier than in others,
the eggs hatch into very small nymphs which on close examination
are seen to resemble adult grasshoppers, but there are no indications
of wings. As they increase in size and molt from time to time, rudi-
mentary wings appear which increase in prominence with each molt
until the last when with fully developed wings the insect is mature

MONTANA EXPERIMENT STATION. 235

and ready to lay eggs. While a few species of grasshoppers pass
the winter as adults and a much larger number as nymphs, thereby
making it possible to find some grasshoppers in the early part of the
summer, it is a matter of common knowledge that they are nmch
more commonly seen in August and September, This is not because
there are more grasshoppers in the latter part of the season but be-
cause when winged they are much more conspicuous than in the
younger stages.

MONTANA'S MOST COMMON AND DESTRUCTIVE

SPECIES.

In the following paragraphs we present a few of the leading facts
regarding the most common species of grasshoppers that we have
taken in middle and eastern Montana. They are not arranged in
the order of their importance except the first five or six. Not all the
species discussed are of great economic importance but all are com-
mon and liable to be observed by anyone. Since some of the species
are not yet known by vernacular names, we have used the scientific
name of all, but have given also the popular name when one is
known.

I am indebted to Prof. Lawrence Bruner of the University of
Nebraska for valuable information concerning our species and for
the determination of a large number of species including a part of
those discussed in this paper. Dr. L. O. Howard of the Division
of Entomology at Washington has also very kindly identified a num-
ber of species for me.

Aulocara elliotti Thomas. THE BIG-HEADED GRASSHOPPER.

This grasshopper, in point of numbers, stands first in the series
here discussed. While it has been mentioned as being injurious in
various parts of the United States, it has never before been consider-
ed a prime cause of devastation. It occurs throughout western
United States and is a true grass-eating species. When viewed from
above or from the side the head is large (see figure) and the tibiae

236 MONTANA EXPERIMENT STATION.

are bright blue; the antennae of the male are long. It occurs prin-
cipally on the range, in Montana, having seldom been found in ir-
rigated valleys.

Melanoplus atlanis Riley. 'THE LESSER MIGRATORY LOCUST

This species is distributed throughout most of the United States
and Canada and often becomes so abundant as to be injurious. In
'Montana we have found it in cultivated fields where it has occasion-
ed considerable loss, and on the range where in association with A.
elliotti it has been injurious. The tibae are usually red. The size and
general appearance of the species are shown on the accompanying
plate (Plate IV, figures i and 2).

Camnula pellucida Scud. THE YELLOW-WINGED LOCUST.

It may be safely said that not a year passes in which this spe-
cies does not become injurious in either one part or another of the
United States, usually in the northwest. It feeds particularly on
grasses and grain. In Montana it has been found to be local in its
distribution and has been destructive on the range in only a few re-
stricted areas. The under wings are yellow, the upper wings and
general surface of the body are variable in color, between yellow and
brown.

Melanoplus hivittatus Say. THE TWO-STRIPED LOCUST.

This is among the larger grasshoppers of Montana. It occurs
throughout the greater part of the United States. It is especially in-
jurious in cultivated fields and so far as our experience goes is
practically the only species that has caused injury to alfalfa. The
femora have longitudinal stripes and there are two yellowish stripes
on the back.

Hjppiscus neglectus Thomas.

We found this grasshopper to be fairly common over the larger
part of the aft'ected territory. Its appearance is well shown in the
accompanying figure. (Plate VI, figure 2.)

MONTANA EXPERIMENT STATION. 237

Spharagemon sequale Say.

This grasshopper is often met with in the heat of the day, is
a strong flyer and a difficult one to catch. In some places it was so
common as to be somewhat injurious.

Arphia tenehrosa Scudder.

This grasshopper fies with a clattering sound, often poises it-
self in the air in the heat of the day, remaining in one spot with the
wings rapidly vibrating.

Chortophaga viridifasciata DeG. THE GOAT-HEADED GRASS-
HOPPER.

This exceedingly variable species, found in the early part of the
season, often assembles in colonies. It varies between bright green
and dull brown.

Dissosteira Carolina Linn. THE CAROLINA LOCUST.

This grasshopper is the species known to most people as the one
that poises in the an- making a peculiar rattling or rustling sound,
settling to the earth as the sound dies out. It occurs commonly along
dustv roads and hGt,gravelly places as along railroad tracks. The
writer has often observed it to be abundant in various parts of
Montana.

Cordillacris occipitalis Thomas.

This species occurs on the plains east of the Rocky Mountains.
We have found it very abundant in eastern Montana.

Melanoplus dawsoni Scudder.

This species when mature has rudimentary wings which reach,
only about half-way to the end of the abdomen. The under side is
yellow, with prominent black bands on the abdomen. It has been
common in lowlands in the Gallatin valley and in the Yellowstone
valley.

238 MONTANA EXPERIMENT STATION.

Encoptolophus sordidus Burn. THE CLOUDED GRASvSHOPPER

Often met with in the field and somewhat resembles C. pellucida.

Acrolophitus hirtipes Say.

This grasshopper of striking appearance, is uniformly green
throughout. It occurs in restricted localities, often in considerable
abundance, where in contrast to other sombre-colored grasshoppers,
it is quite conspicuous.

INSECT ENEMIES OF GRASSHOPPERS.

Grasshoppers have a large number of parasitic enemies and when
the grasshoppers as hosts become abundant, their parasites, because
of a plentiful supply of food, become numerous also and soon gain
the mastery over the hosts. This balancing process is continually
active. While we cannot say positively what is the cause of the ap-
pearance in Montana of grasshoppers in unusual numbers it is prob-
able that parasites as a direct or indirect cause have had a great
influence.

Various correspondents have called our attention to the pre-
sence of minute red spots on the bodies of grasshoppers. These red
spots are the bodies of a red mite which occurs commonly through-
out the state, and which doubtless does some good in preventing the
undue increase of grasshoppers. They have often been mistaken for
eggs of parasites but there is no reason for confusing the two, since
the eggs of parasitic flies are white.

In every part of the grasshopper affected sections of the state that
we visited in the summer of 1903 we found dead bodies of grass-
hoppers which contained maggots or larvae of a fly. Some of these
were reared in the laboratory to the adult stage and the flies were
sent to Dr. L. O. Howard for determination. He reported -the fly
to be Sarcophaga cimhicis Townsend. We are unable to state
whether this fly killed the grasshopper or whether the larvae were
merely feeding as scavengers on the dead bodies of grasshoppers
that had died from other causes.

It was noticeable that a blister beetle or Spanish fly whose
scientific name has not yet been determined was very abundant
throughout the Yelowstone valley from Columbus eastward. We

MONTANA EXPERIMENT STATION. 239

received a few letters notifying us that these beetles had been in-
jurious to garden phints and other plants of value. This species and
various other of the same family {Melodidae) are well known to be
very beneficial in the larval stage as destroyers of the eggs of lo-
custs. In brief their life history is the following: In the latter part
of the summer they deposit their yellowish colored eggs in the
ground, each female producing four or five hundred eggs. The eggs
hatch in about ten days into long-legged larvae. These larvae are
very active and they run about over the ground search-
ing for eggs of locusts, finding an egg pod they enter
it and begin devouring the eggs. It is said that if two
larvae come upon the same egg-pod a deadly combat oc-
curs, resulting in the death of one or the other, leaving
the successful contestant sole owner of the store of food. As the
larva feeds and grows it molts from time to time producing remark-
able changes, until in- place of the long-legged larva there is one
with short legs and rudiamentary mouth parts. The mature beetle
appears again the next spring.

Besides the enemies we have mentioned, which are among the
most important, are many others .which, taken together, doubtless
do much to reduce the number of grasshoppers.

REMEDIES.

The remedies that have been devised in the various parts of the
country are not adapted to the conditions we find on the grasshop-
per-ridden ranges of Montana. They apply much better to the agri-
cultural fields of the middle west states, but some of them may be
used effectively in the agricultural valleys of this state. We give
below a few remarks regarding the most important remedies that
are known, leaving the farmer to select for himself the one most
suitable for his conditions.

Ploughing. — Late fall or early spring ploughing is the best of all
artificial remedies. It is practiced for the purpose of destroying the
eggs and it follows that the eggs must first be located. In our re-
marks regarding the habits of grasshoppers we have called atten-
tion to the fact that in the breeding season the grasshoppers accumvi-
late in more or less restricted areas and that the eggs are laid in

240

MONTANA EXPERIMENT STATION.

these areas. The observant farmer will locate these patches and
by ploughing deeply will place the eggs so far under the soil that
when the young hatch they will be unable to reach the surface. Even
the young hoppers, when very small, may be turned under in the
same manner.

Where ploughing cannot be resorted to, a thorough harrowing,
especially with a disc harrow, will result in the destruction of a
large number of the eggs by crushing some and exposing others to
their numerous enemies and to frosts.

Burning. — When the grasshoppers are young and travel slowly
they may be killed on or near the locality where they hatch by
covering them with a thin layer of straw, and then burning it.

In some sections of the west where crude petroleum can be ob-
tained at small cost it is sometimes employed in the form of a spray
as a remedy against young hoppers. This oil kills by contact but
additional effectiveness can be secured by setting fire to the oil
on the ground.

Bandages. — Some property owners in Montana have suffered
injury to their fruit trees by grasshoppers. The young may be pre-
vented from climbing the trees by bandaging the trunks with cot-
ton batting, axel giease or some other adhecive substance. As the
grasshoppers acquire wings they may fly into the trees and in such
cases relief may be secured by the use of poisonous sprays.

Hopper-dozers. — Hopper-dozers are metallic pans of any con-
venient dimensions which are partly filled with kerosene oil and
■drawn about over the field for the purpose of catching the partly
grown grasshoppers. Many of the insects after hopping into the

Fig; 10 Hopper-dozer, after Riley.

MONTANA EXPERIMENT STATION. 241

pans and getting covered with oil jump out again but these are in-
variably killed. The back of the pan is extended vertically by means
of a strip of cloth or canvas supported by upright stakes. See Figure
lo. In large fields several hopper-dozers are sometimes attached in
series by means of a long pole and drawn by two horses, one at each
end of the pole. IVo horses attached in this way are much better
than one in the middle of the pole because they tend to gather in the
grasshoppers rather than drive them away.

The Artificial Use of Diseases. — Under such conditions as occur
on the Montana ranges, where the greater part of the injury by grass-
hoppers has been done, the artificial use of deadly diseases is an at-
tractive subject. It we were able to propagate and distribute a
disease which would be communicated from one insect to another
and so extended ovei large areas, the solution of the grasshopper
problem would be reached. Various experimenters in the United
States have made careful tests of such diseases but thus far very few
encouraging results have been secured.

Realizing that the artificial use of diseases, though offering
small hope of success, constituted the only hope, the Experiment
Station through this department made a careful test of what has
been called the South African grasshopper fungus disease. A sin-
gle tube of this disease from Africa was very kindly given me by
Prof. C. P. Gillette of Fort Collins, Colorado. Cultures on potato
were made and distributed to about 300 applicants in the state. We
also made careful laboratory tests on caged grasshoppers of various
species, but so far as we are informed not one grasshopper was kill-
ed either in the field or laboratory test. The various other entomolo-
gists also failed to get results of decided value. We feel, therefore,
that until something entirel}^ new in the form of a disease is known,
we will still have to wait for Nature to take her course, except where
it is possible, in restricted areas, to use some of the other remedies.

CRIDDEL MIXTURE.

The substance known by this name has lately come into favor
as a grasshopper remedy in some parts of the United States. It
was first brought to public attention by Dr. James Fletcher, govern-
ment entomologist of Canada, who, at the meeting of official entomo-

242 MONTANA EXPERIMENT STATION.

legists at Washington, D. C, 1903, stated that it had entirely re-
placed the cumbersome and inadequate hopper-dozer. It is made

as follows : Take one part of Paris green, two parts of salt and 40
parts of horse manure by measure. Add sufficient water to make the
mass soft without being fluid. Distribute through the field to be
protected in quantity proportioned by .the number of hoppers.

The material may be scattered from a wagon and because of its
cheapness may be used sparingly over fairl}' extensive areas. We
recommend that it be given a very thorough test around the edges
of grain fields and other crops that may be threatened. We know
of no remedv to recommend for use on the the ranges.

THE COMMON TOAD*

It is the purpose of this paper to call attention to the value of
the toad to the fruit-grower, the gardener and farmer, to outline its
habits and life history and to urge that it he protected against de-
struction by thoughtless boys.

At first thought an account of the toad may seem out of place
in a report of insect life. It is entered, however, on account of my
firm belief in its great economic value as a destroyer of terrestrial
insects, a large number of which are injurious to the interests of
man.

As will be noted, I have freely consulted and often quoted Mr.
A. H. Kirkland's paper that treats of this animal, published as a
bulletin of the Massachusetts Experiment Station. His paper is the
most valuable that has been published on this subject.

FALSE IDEAS CONCERNING THE TOAD.

Since before the beginning of the Christian aj-ea students have
observed toads and written of their habits. Too frequently, however,
actual facts and superstitions have been confounded, with the re-
sult that the early literature on this interesting and valuable batrach-
ian is a queer medley of fact and fiction.

For the sake of brevity we will pass over this topic very briefly
and omitting an account of the venomous character and medicinal

*Bufo bo re as

MONTANA EXPERIMENT STATION. 243

virtue, as well as many other equally ludicrous qualities attributed
by the ancients of Europe to this harmless and humble animal, will
touch upon certain beliefs that are now current in this country.

Perhaps the creation of the imaginpcion ih it is s^iven more cred-
ulity than any other, is, that to touch a I;oad Avill cause warts on
the hand. Other beliefs that have beer, lieid m this countrv, (we
hesitate to say that any of them are now lielcl) are, that t«) kill a
toad will produce bloody milk in cows; ihat a toad's breath wiil
cause convulsions in children ; that a toad in a newly dug well will
insure a good and unfailing supply m" \v;i<;er; ynd that a toad m a
new made cellar will bring prosper ii\- lo rhe hoi-sehold.

No less absurd than the above are the statements
that we often see in the papers to the effect that some
particular section has been visited by toads that fell in
a recent storm in such numbers as to be very abundant
in the roads, on the sidewalks and over the entire surface of the
ground. While it may not be an e;itire impossibility for a toad
to be picked up by a tornado or C3^clone, no one would accredit such
an atmospheric condition with the power of selecting toads from
among the other equally movable objects, or if other objects were
taken into the upper air along with toads we might rationally predict
that both classes of objects would be deposited in the same places.

The explanation of the occurrence of toads in noticeable num-
bers is usually to be found in the fact that they have either hatched
and grown to a suf^ficient size for migration in some nearby swamp
or pond, or that adult toads are on their way to or from such near-
by breeding places. It is well known that toads during the sunny
hours of the day seek protection under stones, boards, bridges, in
dense vegetation jr in the soft earth — in other words, moist, cool
locations. For a short time after a storm, when the air is cool and
the earth and vegetation are wet, the toads are known to venture
forth even at midday as they do in the cool twilight hours of the
evening and morning.

LIFE HISTORY AND HABITS.

The toad in common with other batrachians, and like reptiles,
spends the winter months in hibernation. In the early spring, when

244 MONTANA EXPERIMENT STATION.

the earth has become warmed, the toad emerges from its winter
quarters, and, during the warm hours of the day, makes its way to
some pool or stagnant water where it meets others of its kind. A
little later, their shrill cry, the mating call, may be heard. The eggs
of the toad and those of the frog may both be found in the same pool,
the former in long slimy strings, the latter in irregular masses. In
about four weeks the eggs hatch and the tadpoles, which at first
are very small and very numerous, feed on the vegetable detritus
and slime which are found on the bottom of the pond and attached
to weeds, sticks, etc.

The tadpole has become full grown and has transformed to a
very small toad by about the first of August, in this climate. The
young toads leave the pond and scatter in all directions, keeping out
of sight because of their sensitiveness to heat except after showers
when the earth is cool and damp.

Kirkland states that he removed 1279 ova from one average-sized
female which had already commenced laying. This statement indi-
cates great powers of multiplication in this animal. We have ob-
served, however, that a large proportion of the tadpoles never mature
into toads.

For hibernating quarters the toad makes use of cavities under
rocks, in cellars, in rubbish heaps, etc.

Both in summer and in winter the temperature of the amphi-
bian and reptilian body is about that of the surrounding air or water.
When the surrounding medium goes below certain temperatures,
the animal becomes torpid, stiff and may even freeze without injury.
If brought into a warm room such an animal soon becomes active
as in the summer only to return to the same stupor when returned
to the cold. That the physiological state of hibernation is not de-
pendent alone on a fall in temperature is shown by the fact that the
many animals go into hibernation long before the approach of cold
weather and, fvirther, by the fact that other animals hibernate in
warm weather durmg the period that their appropriate food is
scarce. Some animals, morever, are not aroused from their hiber-
nating torpor by being brought into a warm atmosphere.

When roughly handled, the toad sercets from the wart-like pro-
jections on the back a milky fluid of a most offensive odor. That

MONTANA EXPERIMENT STATION. 245

this secretion is not objectionable to all animals is shown by the
fact that hawks, ow^s, etc., include toads in their fare.

LENGTH OF LIFE OF THE TOAD.

European literature gives authentic record of a toad that lived
36 years and was then killed by accident. Kirkland, in his paper al-
ready referred to, records the results of his inquiry into this inter-
esting matter in the following words :

"Nearly every old New England homestead has one or more
semi-domesticated toads whose age can only be conjectured. The
writer has sought different parts of the state (Massachusetts) among
families who have long resided on the places they now occupy, for
some accurate information on this subject, and from a mass of state-
ments, given in many cases with strong corroboratory details, there
may be taken apparently veracious records of two toads that have
occupied dooryards in two different towns for twelve and twenty-
three years respectively. The histories of these toads have been
given me by people of unqustionable veracity, yet I hesitate to pre-
sent the records as facts, since from the evidence offered I cannot
feel positive that the identity of the toad in either case has remain-
ed unchanged. There can be but little doubt that toads live to a con-
siderably greater age than is supposed and we may hazard the
opinion that many of them reach an age of at least ten or fifteen
years."

FEEDING HABITS.

Particularly in the dry climate of Montana, toads are seldom
seen during the sun-lit hours of the day. That they occur here,
however, is known to all observing people.. In the spring of the
year they may be found in large numbers in ponds and pools.

The toad takes only living, moving animal life as food. Dead
food is rejected. Motionless living food is likewise rejected as has
been observed by the writer and other authors. Insects that "play
'possum" and remain motionless are not taken by the toad.

Unlike the tongue of most other vertebrates that possess this
organ, that of the toad is attached only at the anterior end where
it is fastened to the floor of the mouth. It is coated with an adhesive
substance that causes insects to adhere when touched bv it. Bv a

246 MONTANA EXPERIMENT STATION.

very quick .motion the tongue leaves the mouth, touches and picks
up the food, and returns. So quick is the motion that the* eye can
scarcely follow it.

While out on their foraging expeditions these animals show in-
teresting traits. J\li. Kirkland observed eight good-sized toads
seated under an arc light engaged in picking up insects, which, de-
prived of their wings, fell from the lamp above. A physician in
Maiden, Dr. Charles Burleigh, observed that a colony of some half
dozen toads made their abode under his piazza, and each summer
night about eight o'clock went forth down the walk and into the
street where they stationed themselves under an arc light. Here
they fed upon the insects that fell from the lamp until the electric
current was turned off when they returned to their accustomei
shelter. From his observations, Mr. Kirkland concluded that mider
ordinary conditions toads feed continuously throughout the r'ight
except where food is abundant. He observed thnt iti twenty-four
hours the food consumed was equal to "four times the stomach
capacity.

It would be interesting to follow in detail the results of Mr.
Kirkland's examination of the stomach contents of 149 toads but we
must abbreviate and summarize.

Various investigators have shown, and it is a matter of common
observation, that the toad takes pretty much any living animal food
that crosses its path, provided it is not too large to be swallowed
whole. It follows then that in various parts of the country the diet
of the toad will be determined largely by what are the common in-
sects found on the ground and low-growing vegetation, where the
toad can reach them. The following table by Mr. Kirkland shows
the results of the examination of 149 stomachs contents, in Mas-
sachusetts. Were such a study to be made in Montana the gener-
al character of the food would be the same but in detail it would
be very different.

Unidentified material 5 per cent.

Gravel i per cent.

Vegetable detritus i per cent.

Worms I per cent.

Snails i per cent.

MONTANA EXPERIMENT STATION. 247

Sow-bugs 2 per cent,

Myriapods lo per cent.

Spiders 2 per cent.

Grasshoppers and crickets 3 per cent.

Ants 19 per cent.

Carabids 8 per cent.

,. Scarabaeids 6 per cent.

Click beetles 5 per cent.

; Weevils 5 per cent.

Chrysomelids i per cent.

Carrion beetles '. i per cent.

Miscellaneous beetles i per cent.

Total beetles 27 per cent.

Cut worms 16 per cent.

Tent Caterpillars 9 per cent.

Miscellaneous larvae 3 per cent.

Total cut worms, caterpillars, etc. 28 per cent.
The gravel and vegetable detritus were doubtless taken by
accident in the rapid stroke of the tongue with which the food is
taken into the mouth. It may, however, be of some value in grind-
ing up the food, though it is not always found in the stomach. Of
the total food 98 per cent is animal and by far the greater part of
this is insect life.

In this brief account we will not discuss each of the items
in the above table, but we would call attention to the large pro-
portion of grasshoppers, ants, scarabaeids, click-beetles, weevils,
chrysomelids, cut-worms, tent caterpillars, and miscellaneous lar-
vae all of which are' for the most part injurious.

THE AMOUNT OF FOOD THE TOAD EATS.

When in the presence of abundance of food the toad eats a very
large amount. Mr. F. H. Mosher of Massachusetts fed between
thirty and thirty-five full grown celery worms to one toad in three
hours time. Mr. J. E Wilcox, an employe of the Gypsy Moth Com-
mittee of the Massachusetts State Board of Agriculture, before that
•committee was abolished and its work abandoned, fed to a toad
■of medium size twenty-four fourth molt gypsy moth larvae, all of

248 MONTANA EXPERIMENT STATION.

which were swallowed in less than ten minutes. Mr. Kirkland
found in a single stomach the remains of twenty-seven myriapods,
in another fifty-five army worms, in another sixty-five gypsy moth
caterpillars and in another thirty-seven tent caterpillars.

It is not possible to make even an approximate estimate of the
financial equivalent of the saving to crops brought about by the
toad, but the foregoing facts are enough to remove any shadow
of doubt that this humble animal is of great value to the gardiner^
florist, fruit-grower and general agriculturist.

THE TOAD SHOULD BE PROTECTED AND FAVORED

The wanton destruction of toads by ubiquitous boys is known
to all. It is not an uncommon thing for a party of boys to or-
ganize an expedition to nearby ponds for the express purpose of
killing toads. Dr. C. F. Dodge, published in the Worcester (Mass.)
Evening Gazette, March 31, 1897, an account of finding in a sin-
gle day two hundred dead or wounded toads on the shores of a
pond on the grounds of Clark University.

We should not blame the boys alone for this, the parents and
school authorities are in a measure responsible for this worse than
useless taking of life. Rightly trained and directed the boy can get
more real pleasure, and at the same time a pleasure that is infinite-
ly better for him, by observing the habits of toads and other animals.

The toad is as deserving of protection by legislation as are in-
sectivorous birds. The asthetic, to be sure, is lacking, but the as-
thetic side of the question is not the one that prompts us to enact
laws that make it a misdemeanor to kill birds. It is the economic,,
and on an economic basis the toad is as deserving as almost any
bird.

MONTANA EXPERIMENT STATION. 249

A MANUAL OF FRUIT PESTS WITH

REMEDIES.

In this manual we purpose to present in condensed and easily
accessible form the most essential information regarding the more
important insects and fungus diseases that have been recognized in
the state or which are liable to appear at any time. It is our in-
tention at an early date to prepare another manual similar to this
but dealing with farm, garden and lawn pests.

The reader should freely consult the index in seeking the in-
formation he desires. All insecticides and fungicides recommended
are discussed at the end of this section, and formulae for their pre-
paration are given.

Unless the fruit-grower is confident that he knows the pest he
ie dealing with he should send examples to the Experiment Station
for identification.

INSECTS INJURIOUS TO THE APPLE.

I, The Red-humped Apple Tree Caterpillar.

Bright colored caterpillars with a red hump on the back, feeding
on the foliage of apple. Seldom very abundant.

Remedy. — Remove by hand or spray with an arsenical poison.

2, Tent Caterpillars.

•■ Hairy caterpillars with a bright bluish stripe down the middle
of the back. Living on wild and cultivated cherry and on apple in
the spring of the year. They construct tents or nests in the crotches
of limbs from which they venture and feed during the middle of
the day.

Remedv, — Remove the tent bv hand, taking care to do so when
the caterpillars are home. Under some conditions it is feasible to
locate and destroy their eggs during the winter. The eggs appear
as thickened bands on small twigs. Individual eggs are cylindrical
and in the cluster r.re placed on end, side by side.

250 MONTANA EXPERIMENT STATION.

3, The Bud Moth.

Brownish caterpillars with black heads, feeding in the opening^
buds of apple, pear, blackberry, raspberry, and other plants in the
spring of the year. Sometimes very injurious to apple, destroying
the fruit buds, and by eating out the terminal-growing shoots, caus-
ing a bushy appearance of the side buds and giving the tree an un-
natural appearance.

Remedy. — Keep the buds coated with an arsenical poison in
the spring of the year.

4,. Canker Worms.

Not yet found in Montana. Appearing soon after the foliage is
expanded in the spring. Rapidly devouring the foliage or turning
it brown. Whole orchards may be seen to be of a brown color at
a distance, as a result of the attacks of this insect. When an in-
fested limb is jarred the slender caterpillars, about three-fourths of
an inch long let themselves down by silken threads.

Remedy, — Spray promptly and thoroughh' with an arsenical
poison as soon as tlieir presence is first detected. In regions where
they are suspected to be present it is well to keep the trees banded
with building paper and smeared with an adhersive substance which
may be watched in the spring of the year for the purpose of learning
whether or not the wingless moths are ascending the trees to lay
their eggs. A large proportion of the damage may be averted by
the lise of such bands. "Bodlime," sold by the Bowker Insecticide
Co., Boston and Cincinnati, is a good adhesive substance to use for
this purpose. Tar or printer's ink may be used but are less sat-^
isfactory.

5, The Codling Moth.

The larva is Known as the apple worm and infests a number of
fruits, but is most injurious to apple and pear. It is probably the
most important pest with wliich the Montana fruit-grower has ta
deal.

Remedy. — Spray with Paris green, arsenate of lead or arsenite
of lime after the petals have fallen, again two weeks later, again
the first week in August. If it is not yet in your orchard, watch for
its appearance by searching for wormy fruit among the wind-falls

MONTANA EXPERIMENT STATION. 251

and when harvesting the crop, and if the pest is found, begin spray-
ing the next season. Do not bring to your orchards second-hand
boxes from fruit dealers in town ; it is against the laws of the state
and you are liable to prosecution. Such a practice will almost sure-
ly result in the establishment of the pest in your orchard.

6, The Web-worm.

Colonies of hairy caterpillars living in tents on fruit and shade
trees in the latter part of the summer and early fall. Affected limbs
are enclosed in nets and the leaves are brown. .■ f

Remedy. — Remove the caterpillars by hand. --, .- v

7, The Flat-Headed Apple-tree Borer.

Fairly common on apple trees in western Montana. Prefera-
bly attacks diseased or weakened trees and feeds in the larval stage
in the trunk and larger branches, excavating irregular cavities
under the bark and later boring into the deeper parts of the tree. It
may often be detected by sunken or discolored patches in the bark.

Remedy. — Not an easy insect to combat. Practice clean culture.
Dig up and bum worthless trees that are infested. In some cases it
is advisable to locate the burrow of the borer and dig out the grub
by means of a sharp knife or wire or other suitable instruments,
taking care not to injure the tree more than necessary. Use deter-
rent washes.

8, The Round Headed Apple-tree Borer.

Large, legless borers in the trunks of apple trees near the
ground. The anterior end of th body is of about the same diameter
as the posterior part.

Remedy. — Treat as for flat-headed borer.

9, Apple Twig-borer.

Small, cylindrical, mahogany-colored beetles about one-third of
an inch long, boring holes in twigs of apple, pear, cherry and other
trees and in grape vines. ^

Remedy. — Prune ofif and burn infested stems.

10, Leaf-hoppers.

Small soft-bodied insects with sucking mouth parts, on the
under side of the foliage of apple and other fruits. Another species
is known on pear, still another on rose.

252 MONTANA EXPERIMENT STATION.

Remedy. — Spray the under side of the foliage with kerosene

tmulsion early in the season before the insects acquire wings and

are able to fly.

II, Buffalo Tree-hopper.

i Greenish or brownish three-cornered insects which make longi-
tudinal slits in the bark of apple, laying their eggs in the slits.

Remedy. — Prune off and burn affected twigs, practice clean
culture, keeping out all weeds and unnecessary vegetation.

12, Woolly Aphis of the Apple.

*■ May be detected by the whitish woolly masses on the water-
sprouts at the base of the tree and on old scars on the trunk and
limbs. The colony masses are made up of the bodies of the lice and
cottony secretion produced by them. The most injurious form of
the insect feeds on the roots of the trees.

Remedy. — For the areal form use strong kerosene emulsion
early in the season. For the root form dig away the earth down to
the roots and soak with hot water and return what has been removed.

13, The Apple Leaf-aphis.

Dark-green lice on the leaves of apple, causing them to curl.
Common throughout the state. More abundant on young trees.

Remedy. — When only a few terminal branches are affected, dip
the affected parts into a pail of kerosene emulsion. One part in nine
of water, or whale-oil soap solution, one pound in eight gallons of
Ivcfter. Early in the season it is well to single out individual affect-
ed trees ind spray with one of the above solutions.

14, The San Jose Scale.

An insect which has caused great destruction in the United
States but which would probably be much less injurious in Montana.
Minute circular scales on the bark of practically all our common fruit
and shade trees. When abundant, giving the trees the appearance
of being coated with a laj^er of ashes.

Remedy. — Spray with lime, sulphur wash when trees are dor-
mant. ,„

15, The Oyster-shell Bark-louse.

Brownish scale insects, one-twelfth of an inch long, elongated

MONTANA EXPERIMENT STATION. 253

in form, occurring on various plants but mostly on apple, on which
it is most abundant at the ends of the twigs.

Remedy. — Watch for the exceedingly minute whitish larvae
early in June and when they appear spray with kerosene emulsion,
one part in nine of water. Repeat in a few days if more larvae arc
seen.

i6, Putnam's Scale Insect.

This insect occurs sparingly in western Montana. Resembles
the San Jose scale, being a degraded form of life that lives under
a very inconspicuous scale closely adhering to the bark.

Remedy. — If necessary to treat for this, wash with strong whale
oil soap solution while the trees are dormant.

17, The Scurfy Bark-louse.

A white scale insect on the bark of apple, pear, currant and
other rosaceous plants.

Remedy. — Watch for the young to hatch early in June and
spray with kerosene emulsion, one part in nine of water. If neces-
sary spray again ten days later.

18, Mealy Bug on Apple and Pear.*

Occurs in the 'vicinity of Missoula. White cottony or mealy
masses around the buds in the spring. Found in the winter under
the scales of bark. Has been reported as injurious to young trees.

Remedy. — Use whale-oil soap or kerosene emulsion as strong as
the trees will stand. In the winter search for and destroy the cot-
tony masses on the trunks of the trees, using whale-oil soap as

a wash.

19, Ants as Fruit Pests.

We have received reports of ants as being injurious to young
friut trees, building their mounds at the bases of the trees and eating
off the bark and girdling the trunk. We have also known ants to be
injurious to apple trees by gnawing the buds in the spring of the
year.

Remedy. — Pour bi-sulphide of carbon into the colonial mounds ;
from one to five or six tablespoonfuls should be enough. This sub-
stance must not be put close to the trunks of apple trees.

*Phenacoccus sp.

254 MONTANA EXPERIMENT STATION.

20, Grasshoppers.

Young grasshoppers sometimes crawl up the trunks of trees and
devour the foHage. Later when they acquire wings they fly into the
trees.

Remedy. — Spray the foliage heavily with arsenate of lead. To
prevent the young from ascending the trees ; tie belts of cotton about
the trunk or smear printer's ink or some other adhesive material
on a band of paper on the trunk.

21, The Clover Mite.

Giving the leaves of apple and other trees a whitish devitalized
appearance. In the fall of the year and during the winter masses of
very minute reddish eggs may be found on the trees, particularly
in the crotches. The mites sometimes become annoying on lawns
and in dwellings by crawling through the windows.

Remedy. — Spray affected trees with the 1-1-4 formula of lime-
sulphur wash in the fall or early spring, while the trees are bare of
leaves. Spray with kerosene emulsion to destroy the pest in the vi-
cinity of the house.

INSECTS INJURIOUS TO THE PEAR.

22, The Pear-leaf Blister-mite.

Generally distributed in Western Montana. Causing thickened
reddish spots and blotches on the leaves of pear; later in the season
the spots die and turn brown, sometimes causing the foliage to drop
prematurely. Serious on individual trees but does not spread very
rapidly.

Remedy. — To prevent spreading, gather and burn the fallen
leaves from invested trees. Spray in the spring before the buds
open with the 1-1-4 lime-sulphur wash.

23, The Pear Slug.

Injurious to the leaves of pear, plum and cherry. Slimy slugs
on the upper side of the leaves, eating off the surface parts, leaving
the under surface and the network of veins, which later turn brown,
giving the parts of the tree affected a brownish appearance.

Remedy. — Spray with arsenical poisons or dust or spray with
hellebore.

MONTANA EXPERIMENT STATION. 255

INSECTS INJURIOUS TO CHERRIES.

24, The Cherry Aphis.
A dark colored aphis on the under side of the leaves of cherry.
Common in western Montana. Occuring throughout the state.
Remedy. — Treat as for apple-leaf aphis.

INSECTS INJURIOUS TO THE PEACH.

25, The Peach Tree Borer.

Primarily a peach pest, but attacking also cherry, prunes and
plum. Boring in the trunks near the ground, causing characteristic
gummy masses to exude on peach trees. The injury is most appar-
ent in the spring.

Remedy. — A difficult pest to control. Keep the trees well fed
and in a healthy growing condition. Prof. Slingerland has recom-
mended the use of gas-tar smeared on the trunks to prevent the
moths from depositing their eggs, and in combination with this the
digging out method to destroy such larvae as gain access to the trees.

26, The Peach^Twig Borer.

Though not yet found in Montana, it may turn up at any time.
Reddish pink caterpillars boring in the young tender twigs of peachy
plum and prune in the early spring, later feeding in the fruit near
the pit.

Spray with strong kerosene emulsion in the winter. The oil de-
stroys the worms by penetrating into the holes.

INSECTS INJURIOUS TO PLUMS AND PRUNES.

27, Plum Gouger.

Small beetles, about a quarter of an inch in length, of a leaden
gray color with a yellowish head and thorax, eating pinholes in
growing plums. The larva of grub feeds in the pit, later eating its
way out through the pit and flesh of the plum just as the fruit ma-
tures. Attacks only American varieties.

Remedy. — Jar the trees early in the morning or in the evening
when the trees are in bloom and the fruit is setting, catching the
beetles that drop on a sheet spread underneath. A few beetles are
able to do a great damage. Prof. Gillette found that a single female

256 MONTANA EXPERIMENT STATION.

lays as many as 450 eggs. Gather and destroy all the stung plums
l)eforc the grubs escape. Spray heavily with arsenate of lead be-
fore the blossoms are out.

28, The Plum Curculio.

The beetles make a crescent-shaped slit on the fruit of the plum.
The larva feds in the young fruit causing it to drop. Said to be in
the Bitter Root valley.

Remedy. — Spray thoroughly with arsenical insecticides before
the leaves open. Jar the trees in the early morning catching the bee-
tles on canvas or a sh^et and destroying them by burning or cruch-
ing. Promptly gather and destroy fallen fruit.

29, Plum Aphis.

Numerous pale-green lice on tender shoots of plum. Common
in Montana, sometimes injurious.

Remedy — Treat as for apple aphis, but use extra precaution as
the plum foliage is much more liable to be injured by insecticides.
30, The Box Elder Plant-bug.

Sometimes very injurious to foliage and fruit of plum and
prunes. Feeds primarily on box elder. Red and black bugs with
a long, jointed snout

Remedy. — Spray with kerosene emulsion to kill the young in-
sects. It is sometimes necessary to remove neighboring box elder
trees for the sake of doing away with the breeding place of the
insects.

INSECTS INJURIOUS TO THB STRAWBERRY.

31, The Strawberry Leaf-roller.

Generally distributed in Montana, and at times a destructive
species. Feeds on strawberry, blackberry, raspberry and other
plants. Rolls or crumples the foliage. Larvae small, greenish in
color.

Remedy. — After harvesting the crop, mow the vines, leaving
them to dry. Then burn them. If there are enough vines to burn
well first put some hay or straw over the field. If preferred vines
may be sprayed with arsenate of lead after harvesting the fruit.

32, The Tarnished Plant-bug.

Common throughout the state. Native to Montana, feeding on
many wild plants. About one-fourth of an inch in length, variable

MONTANA EXPERIMENT STATION. 257

in color, but usually marked with yellow, black and brown. Flies
when disturbed. Most injurious in the spring of the year when they
attack tender shoots and opening buds. Most commonly known in
Montana as an enemy to blossoms and young fruit or strawberry
and to young trees in the nursery row.

Remedy. — It is not always easy to control this insect. When
found on young fruit trees, jar them off in the cool of the day into
some receptacle which contains kerosene oil.

33, Strawberry Root Weevil.*

Small hard beetles with an elongated snout which feed on the
foliage of strawbenies in the early summer The larvae feed on the
roots and are very injurious.

Remedy. — Delay the planting of the new crop until the beetles
have deposited their eggs. Keep the foliage coated with arsenate
of lead in the early part of the summer.

34, Strawberry Crown Borer.

Small yellowish white grubs boring in the crown of plants dur-
ing the summer. A species which though not yet recognized in Mon-
tana is liable to be introduced at any time on imported plants.

Remedy. — In a field that is known to be infested do not allow
the plants to become very old but start a new bed at some distance
from the old one ; burn over the patch as for the strawberry leaf-
roller.

IN5ECT5 INJURIOUS TO CURRANTS AND GOOSEBERRIES.

35, Native Currant Saw-fly.

Pale-green larvae which appear in the latter part of June or
early in July and very rapidly devour the foliage of gooseberry and
current bushes. The second brood appears about three weeks later.
Shows preference for gooseberry.

Remedy. — Dust the bushes with powdered hellebore or spray
at the rate of one pound to a gallon of water. Be prompt in the
treatment and do not allow them to defoliate the bushes.

36, Currant Flies.

Maggots feeding the fruit of the currant, causing here and there

*Otiorhynchus ovatus Linn.

258 MONTANA EXPERIMENT STATION.

a berry to turn red prematurely; in severe cases causing the entire
crop to fall to the ground.

Remedy. — Either gather the fallen fruit frequently and destroy
it, or, after all of the insects have dropped to the ground, turn with
a plow a deep furrow of earth against the row, then with a rake or
shovel smooth the earth down around the bushes so as to cover up
the hibernating insects so deeply that they cannot escape. This
should be done in the fall or early spring.

37, The Currant Stem Borer.

Larvae of a clear-winged moth, a near relative of the peach
borer, which makes burrows in the currant canes, sometimes becom-
ing very injurious.

Remedy. — Watch the currant bushes in the early part of the
summer about the time the fruit is setting and cut out and burn
affected canes which may be detected by the yellowish color or
wilted condition of the foliage.

38, Currant Leaf-hopper.

Minute whitish insects on the under side of foliage of currant
in the early part of the season. Later they acquire wings and have
pinkish markings.

Remedy. — Spray the under side of the foliage with kerosene
emulsion, one part ni nine of water in the early part of the season.

39, The Currant Aphis.

Green lice on the under side of currant leaves, causing the leaves
to turn reddish in color and to have an irregular surface.

■Remedy. — Spray with kerosene emulsion or whale-oil soap solu-
tion. This spray kills only by coming in contact with the lice, there-
fore direct it against the under side of the leaves.

40, Currant Thrips.

Minute reddish insects of elongated form which cluster on
the tender buds and blight them. "

Remedy. — Pick off and destroy the affected parts.
41, Currant Cottony Scale.

Cottony masses on the canes of currant and gooseberry.

Remedy. — Spray with whale-oil soap solution, i pound in 4
gallons of water during the winter. In gardens where it is possible
wash off the cottony masses with a strong stream of water.

MONTANA EXPERIMENT STATION. 259

42, The Gooseberry Fruit-worm.

A near relative of the codling moth which feeds in the goose-
berry fruit, causing it to prematurely turn color and later to drop
off. Several berries are often bound together. Common in the
fruit-growing sections of the state.

Remedy. — Carefully go over the bushes and pick off the affected
berries and destroy them before the worms leave. Do this at least
twice in the season.

FUNGUS DISEASES.

I, Black Spot, or Apple Canker.

This is peculiarly a northwest disease and attacks only the ap-
ple. It is said to occur in western Montana. The disease is confined
to the bark and pioduces characteristic brownish or nearly black
spots. The spores are distributed during the early fall.

Remedy. — Under some circumstances relief may be secured by
cutting out the affected parts. Since the disease spreads from No-
vember 1st to February ist, it is evident that trees should be coated
with a fungicide during this period. On account of frequent storm 5
however, it would be difficult to keep a fungicide on the trees.

2, Crown Gall.

Various plants, including apple, almond, apricot, blackberry,
cherry, chesnut, English walnut, grape, peach, pear, plum, raspberry,
and poplar are affected with abnormal growths on the roots which
have been called crown-gall. These galls vary from a size as big
as a fist or larger down to very small excrescences on the fine roots.
Whether or not all of these trees are affected with the same organ-
ism is not clear. A serious trouble on apple in Montana. Irrigation
seems to favor its development.

Remedy. — Do not plant affected trees. Examine the roots of
all new stock and discard any that shows even the slightest sign
of this disease.

3, Apple Scab.

Attacks leaves and fruit and sometimes also the twigs. Circu-
lar smoky spots oa the fruit which interfere with its development.
Spots begin to appear when the fruit is about half grown. They

260 MONTANA EXPERIMENT STATION.

may be as large as a dime, but are usually smaller. On the leaves
the fungus appears as dark olive green spots which do not have a
distinct border line and occur mostly on the upper side fo the leaf.
Remedy. — Spray with Bordeaux mixture three times and ammon-
iacal copper carbonate (cupram) twice. First spraying of Bordeaux
should be applied just before the blossom open, the second just after
the petals fall, the third about ten or twelve days later. The two
sprayings of cupram should follow the Bordeaux at intervals of two
weeks. Bordeaux is not used in the last two sprayings since it
causes the fruit to russet.

4, Pear Scab.

So similar to apple scab that no separate account is necessary.
Remedy. — Treat as for apple scab.

5, Pear Blight or Fire Blight.

Attacking individual limbs of pear, and occasionally apple and
quince also. Rapidly spreading until the whole tree may be in-
volved. The foliage turns suddenly brown as if by fire and an ex-
amination under the bark shows a fermented condition. This dis-
ease is believed to be distributed by insects that visit the flowers,
as well as by other means.

Remedy. — Cut out the disease as soon as it appears and prune
again whenever necessary. Always cutting below the point where
the disease is reached. It is usually best to cut at least a foot below
the point where the disease appears to end.

6. Gooseberry Mildew.

This troublesome disease usually appears in the spring upon
the developing buds and leaves, first showing as a sparse cob-webby
coating, which later develops into a denser white, powdery coating.
The 3^oung berries are also attacked. A serious disease which very
much interferes with the growing of choice foreign varieties.

Remedy. — Spray with potassium sulphite at the rate of one-
half ounce to one gallon of water, making the first application as
soon as the leaves begin to unfold, repeating the operation at enter-
vals of one to three weeks. The ammoniacal solution of copper car-
bonate would probably be equally effective.

MONTANA EXPERIMENT STATION. 261

INSECTICIDES AND FUNGICIDES.

Arsenate of Lead.

This valuable insecticide is rapidly coming to the front as a
safe and reliable arsenical poison. It can be applied to the foliage
in any desired strength without injury, and when applied remains
through rain storms. Its white color may be detected on the leaves
thereby serving as a guide in its application. It is made by the
union of acetate of lead and arsenate of soda, both being soluble in
water. It is no longer necessary for the user to make his own arsen-
ate of lead for it is now being sold at reasonable prices by the Bow-
ker Insecticide Co , Boston, Mass., and Wm. H. Swift, Boston, Mass.

Paris Green.

Paris green is an old, well-known arsenical insecticide. It was
first brought to prominence in connection with the war that was
waged against the Colorado potato-beetle in the western states be-
tween i860 and 1870

In spraying with this substance a hot day should be avoided if
possible, especially it it is desired to apply nearly


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