| Preliminary Bulletin on
5] Some Economic Insects
and Plant Diseases of Indiana

SB 824
.16 AS
1907

Copy 1

BENJAMIN W. DOUGLASS
State Entomologist

INDIANAPOLIS, INDIANA

1907

A PRELIMINARY BULLETIN

ON

Some Eiconomic Insects and Plant

Diseases of Indiana

BENJAMIN W. DOUGLASS

State Entomologist
INDIANAPOLIS, INDIANA

1907

INDIANAPOLIS
WM. B. BURFORD CONTRACTOR FOR STATE PRINTING AND BINDING
1907

SS WE uevsiee S

Some Economic Insects and Plant Diseases
of Indiana

OFFICE OF THE STATE ENTOMOLOGIST
BENJAMIN W. DOUGLASS

It has been claimed by eminent scientists that all the diseases
of men common in Indiana, even to the notorious malaria of the
swamps, were brought into this territory by the people who came
from the older settlements. A similar statement would hold true
for most of the insect and fungus parasites that infest the plants
of the State. It has not been such a long time since it was possi-
ble to grow fruit of all kinds and have a large percentage of per-
fect specimens in the harvest.

Today, however, there have been so many injurious insects in-
troduced and so many fungus enemies have made their appear-
ance that the problem of the horticulturist and the agriculturist.
is a great one, and one that will tend to increase instead of de-
crease as time goes on. Today the fruit grower, even though he
has but a few trees or berry bushes, must own a spray pump of
some sort, and he must exercise a great deal of judgment in its
use. Spraying has been played up for so many things that the
novice is apt to be misled into thinking that it is a panacea for
all orchard troubles, when, as a matter of fact, it is worthless
unless done intelligently and with a proper regard for the re-
quirements of the particular trouble involved. Before you start
to spray be sure that you know what you are spraying for, and
try to learn the best time to apply the proper spray or poison,
and learn what that poison should be.

We may divide the things that it is necessary to spray for
into three general groups, each group requiring special treat-
ment.

First Group—Biting or Chewing Insects.

This class includes all of the more common larval forms which
damage the plant by actually eating the tissues. They may best
be handled by an internal poison placed on the leaves or other
plant parts that they damage. Of such poisons Paris Green is

(2)

4

the most commonly used and is, perhaps, one of the best. Ex-
amples of this group are the tomato worms, codling moths, elm-
leaf beetles, ete.

Second Group—Sucking Insects.

Insects of this class damage the plants by inserting their mouth
parts through the epidermis and securing their nourishment di-
rectly from the interior of the plant. They can not be reached
by any poison such as would kill the chewing insects, but must
be treated with a remedy strong enough to kill them by direct
contact. This fact makes the sucking insect an especially hard
class to fight, as many of the things used to destroy them are
apt to damage the plant as well. For this class of insects the
most common remedies are Coal-oil Emulsion, Whale-oil or other
soap, strong tobacco juice, and the Lime-Sulphur-Salt wash. The
San Jose and other scales and the plant lice are examples of this
class of insects.

Third Group—Fungus Enemies. .

There are almost innumerable parasitic fungi that infest wild
and cultivated plants, and often they become a very serious pest
and do tremendous damage. They consist of small, often micro- ©
scopic, plant bodies, which live in the body of the ‘‘host’’ plant,
as it is called, and gradually cause its death, either by the de-
struction of the tissues or by the production of a direct poison.

The universal remedy for all such fungi is a solution of copper
sulphate, either pure or with the addition of a certain percentage
of lime, to neutralize the free acid of the sulphate and thus pre-
vent damage to the leaves of the plant.

Then there is another group composed of both the plant and
animal parasites, for which there is but little that can be done.
Among these are the black knot on the cherry and the plum,
and the blight in the pear, and the various kinds of borers that
affect the boies of trees. While we know what the latter are,
we have not ready means of combating them without destroying
the trees. There are many problems that will come under this
latter class, and each requires individual study to develop the
point at which it may best be attacked. For the most part, how-
ever, the problems that confront the farmer and tree grower of
any sort can be found under one of the three first heads given,
and the whole secret in the successful treatment of plant para-
sites is to be sure of what you want to do and then do it thor-
oughly.

INSECTICIDES’

For the First Group—Biting Insects.

The best poison to employ for this class is undoubtedly Paris
Green, as it is easily prepared and is cheap, and its presence can
usually be detected owing to its color, thus preventing it being
taken for any other substance, as it is very poisonous. It is an
arsenic preparation, and when used in solution must be constant-
ly stirred to prevent settling, as it is heavy and settles rapidly.
It is often advisable to add a bit of lime to the Paris Green
solution to prevent any damage to the foliage which might re-
sult if it were used pure. On ordinary foliage, however, it is
not necessary to use this precaution, as it is not probable that
‘any harm will result from the use of the poison. It can be safely
used in the proportion of one pound to one hundred and fifty gal-
lons of water, and this proportion will prove effective for most
purposes.

Other arsenical poisons are not mentioned here owing to the
lack of space and because none of them are any better than Paris
Green and a discussion of them might tend only to confuse the
intending sprayer.

For the Second Group—Sucking Insects.

This class of insects is a very hard one to reach by any method
of spraying, and a great many different preparations have been
tried from time to time, but with variable results. What has
proved successful in one locality has, for one reason or another,
entirely failed when applied by other experimenters at other
places. The advent of the San Jose scale and the increasing
numbers of the various species of plant lice have made spray-
ing with contact poisons a rather recent development in agri-
cultural practice, and today it is far from being an exact science.
Any poison for this class of insects must be strong enough to
kill the insect by contact and still do no damage to the tree,
and this result is sometimes hard to obtain. We can not devote
any time to a review of the experiments that have been car-
~ ried on in various parts of the country for some time, but simply
give the formulas of some of the preparations that have in some
localities been found effective. Probably any of them will prove

a

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effective and harmless to the tree if properly made and carefully
applied. In no ease should any spraying solution be so lavishly
apphed that the tree drips. It will require practice to develop
sufficient skill to spray a tree just enough, that is, until it is com-
pletely coated with the solution and no more.

LIME-SULPHUR-SALT WASH.

The following formula is one that is recognized and recom-
mended by the foremost economic entomologists in the country,
but it may be varied considerably without apparently detracting
from its efficiency.

Time 2807. Ss eee I ete ae eee 50 pounds
Sil plat Seek Se ae ee a ee ae BOM ian
Salt Oe. LSA Ee ee ae Sea ete eee 50 ay
Water! 2-2 U2 auaeae apes MG Bes) oie f 150 gallons

Add enough water to the lime to slake it thoroughly and im-
mediately add the sulphur. Boil for an hour or so with only

water enough to keep thé mass liquid, until the solution be-

comes a deep amber color. Have the salt dissolved in water and
add it to the boiling mass. After it has all been mixed together,
boil for at least another hour and then add water enough to
make up the one hundred and fifty gallons, and spray it as soon
as possible. It is more efficient when used warm, and some of
the failures with this wash have undoubtedly been due to the
use of stale solutions and to careless boring.

One objection to this wash is that it is decidedly “‘messy’’ to
work with, and the man at the spray pump is certain to ruin his
clothing and is fortunate if he keeps the spray from his eyes,
thus causing serious inflammation. It is always advisable with
this or any other spray to wear very old clothing that will never
be used for any other purpose, and to protect the hands and
face in some way. Automobile goggles would serve admirably
to keep the spray from the eyes.

The Lime-Sulphur-Salt wash can only pee used during the
dormant period of the year, as it is fatal to fohage.

For summer use against the San Jose and other scales, and
against the myriad forms of plant lice that are every year be-
coming more and more common, there are several ways of using
coal-oil effectively.

There are now being made certain kinds of spray pumps that
automatically spray a mechanical mixture of coal oil and water

a

7

;

by the use of compressed air. The oil and water are carried in
separate tanks and are conveyed in separate lines of hose to
the nozzle, where they are mixed.

Then there is the old and tried coal-oil emulsion, made by using
any kind of strong soap to keep the oil from separating from
the water. The emulsion has the advantage of staying on the
affected parts of the plant for a longer time than the plain oil.
Sometimes this is not to be desired, as the long application may
-result in foliage damage.

Careless spraying is worse than no spraying at all, for it not
only fails of its object but it is expensive, and it may possibly
result in actual damage to the tree. This is especially true in
the case of the sprays used for the control of the scale insects,
and this department is in no way responsible for any damage
that may result from the use of any spray, whether recommend-
ed in these pages or not. The best that we can do is to advise
the use of sprays that have proved effective in other cases.
Under changed conditions the results may be altogether different.
Effective spraying is largely a matter of individual requirement
and must be intelligently worked out for local conditions.

SAN JOSE SCALE.

(Aspidiotus perniciosus Comstock.)

So much has already been written relative to the danger aris-
ing from infection with San Jose scale that no argument is nec-
essary to convince the average citizen of the desirability of com-
bating this pest with all the vigor that we can command. We
will briefly review its important characteristics and, while it is
not difficult to-recognize, we will call attention to the fact that
the genus ‘‘Aspidiotus’’ contains several other species that are
very similar to the Aspidiotus perniciosus, and any of them may
become very dangerous to plant life. Among these are the Put-
nam Seale (Aspidiotus ancylus Putnam). This is an insect so
similar to the San Jose Seale that even the most expert sometimes
confuse them. It has been claimed that the Putnam Seale does
not become numerous enough to damage a tree, and this state-
ment has led some entomologists to make the mistake of calling
San Jose scales by another name simply because they were not
thick on the tree. In general, it should be remembered, it makes
but little difference what the scientific name of any insect is if

8
it is assured that it is doing damage to vegetation, and any scale
that shows signs of attaining considerable numbers should be
treated exactly as you would treat a well-authenticated case of
San Jose seale.

Life History—The San Jose scale began life as a minute

orange yellow insect, crawling freely about over the trunks and
limbs of trees, whereupon its parent is attached. It is in this
stage that the pest is most generally distributed by birds. It
will crawl upon the feet and legs of the bird and be carried, pos-
sibly, great distances before again happening to crawl off on an-
other tree.

This period of activity continues for, at most, a day or two,
when the young scale settles down and begins to secrete the plate
or seale proper which cements it firmly to the bark. It grows

during the summer, feeding on the plant juices, which it draws —

through the bark with its probocis, and in early fall the eggs are
fertilized in the body of the female by the winged male. —

At the approach of winter the insect (still containing the half-
erown young) ceases feeding and becomes dormant, to resume
feeding at the first sign of warm weather. Early in June the
young attain their full size and emerge from the body of the
parent, thus completing the life cycle. The production of young
is continued throughout the season, two broods appearing, one
in August and one early in October.

Adult Scale——The adult scale appears as a small, rounded
plate, grey in color, the center darker and elevated, the whole
insect not more than one-sixteenth of an inch in diameter. On
a badly-infested tree the scaies will be so close together as to

completely hide the bark, giving the branch an unhealthy, seurfy
look.

SCURFY SCALE.
(Chionaspis furfurus Fitch.)

_ While common and widely distributed, this seale has seldom be-
come numerous enough to cause any material damage.

As will be seen by the illustration, the male and female dif-
fer considerably in form and size. At one stage in its life his-

tory the male is winged, as are the males of the majority of the
seale insects.

ee ee ee et

—_

a .

9

Under favorable conditions this scale may become destructive,
and wherever they seem to be multiplying it would be advisable
to use on them the same measures recommended for the San
Jose Scale.

COTTONY MAPLE SCALE.

(Pulvinaria innumerabilis Rathvon.)

During the past two years the eottony maple scale has killed
many trees in Indiana. It has not been confined to maples en-
tirely, for trees of several other genera have been attacked and
killed. Little or no attention has been paid to it in spite of its
deadly character.

Life History. After hibernating on the twigs of trees all win-
ter, the female lays large quantities of eggs in May and June.
It is at this season that the scale is most conspicuous, clinging
to the under side of the twig and surrounded at one end with
great masses of cottony padding, which is developed from the
body simultaneously with the eggs. This cottony substance is
persistent on the branches through the summer and until worn
off with wind and rain.

The eggs hatch in a short time and the young at once migrate
to the leaves, where they attach themselves in rows along the
veins and begin feeding. They grow rapidly, and as summer ad-
vances the males and females are differentiated, the males de-
veloping wings. At the approach of fall the fertilized females
attach themselves to the under sides of the twigs, where they
remain all winter. The male dies at the end of the summer.

Treatment.— Winter spraying with Lime-Sulphur-Salt wash or
with whale-oil soap is the best means of controlling the cottony
seale.

On affected trees the leaves fall persistently throughout the
season, often ending with the death of the tree. These leaves
should be carefully raked up and burned, as they are an active
source of infection for other trees.

Summer spraying would have to be very thorough to be ef-
- fective, as every leaf on a badly affected tree is a host of in-
“numerable scales. Sometimes a tree that has been completely
stripped of its leaves and seemingly killed will put forth a new
set of foliage in the fall, but it is not likely that such a tree could
withstand the succeeding winter.

10

PLANT LICE. (Aphids.)

There are many kinds of plant lice that affect cultivated plants.
Almost all of them are dangerous and require prompt treatment.
Many lice, such as the cherry and apple aphids, winter in the
ege state, and the eggs are laid on the young twigs of the trees.
In this way they may be distributed in nursery stock. The
woolly apple louse forms a characteristic grayish cottony mass
about it. It feeds on the apple and is one of the worst pests we
have to deal with. Owing to the fact that one stage of the in-

sect infests the roots of the trees, it is very difficult to treat, and’

a tree that is badly infested should be destroyed and the ground
thoroughly dug up and exposed to the air. It will be safe to
replant the same spot with another tree, but not with an apple.
I have had partial success in treating this louse with carbon bisul-
phid, using an ounce of the liquid in each of several holes punched
in the ground around the tree at a distance of about two feet
from the trunk.

During the season of 1907 the common oat louse became so
plentiful that many fields of oats were ruined. The only practi-
cal treatment so far suggested is to burn over the fields and thus
reduce the number of individuals to affect next year’s crop. The
same field should not be planted in oats again without a rotation
erop of clover or corn. The number of lice was due probably
to the peculiar weather conditions of the preceeding spring. Ac-
companying the presence of the oat louse was a characteristic
red rust that sometimes affects the grain regardless of the pres-
ence of any insect. lice on the rose bushes sometimes become so
numerous as to kill the tender growing tips or to destroy the
foliage. In green houses it is a common practice to use tobacco
smoke—in the open a strong. solution of tobacco made by boil-
ing cheap clippings and stems will prove very effective if sprayed
on the affected parts. For any of-the lice this tobacco solution
is a standard remedy. Where there is a large area to be treated
the coal-oil emulsion will be found to be cheaper and perhaps
more effective.

Ee a eee Peer nae ee ee

let

SAN JOSE SCALE. SLIGHTLY ENLARGED.

(3)

MES AS COMMON

WHERE IT BECO
IN THIS SPECIMEN THIS INSECT IS QUITE

ENLARGED.

YSTER SHELL SCALE.

O

AS SHOWN

AS INJURIOUS AS THE SAN JOSE SCALE.

13

SCURFY SCALE. (MALE) SLIGHTLY ENLARGED.

14

LARVA OF THE CECROPIA MOTH, A TYPICAL CHEWING INSECT. NATURAL SIZE.

15

3
i
;
f
|
Ti

K MOTH

THE WORK OF THE TUSSOC

16

FALL WEB WORM AND ITS WORK.

Ep

WORK OF THE CATALPA SPHINX MOTH. WHERE IT HAS MADE
ITS APPEARANCE THIS INSECT HAS RENDERED
CATALPA GROWING IMPOSSIBLE.

18

TWENTY-SIX

IN THIS PLANTATION

PER CENT. OF THE TREES HAVE BEEN EATEN OFF,

IF THE LOCUST BORER.

WORK O

AND

ALL OF THE OTHERS ARE AFFECTED.

1§
CODLING MOTH.

_ It is the presence of this insect that makes apple growing dif-
‘ficult in this country. It is practically impossible to grow apples
in Indiana without spraying and secure anything like perfect
fruit. The insect hatches from the cocoons in the late spring
and at once lays its eggs on the young apples, mostly at the
flower end. The trees should be sprayed just after the blossoms
fall so as to fill the calyx with the poison, as many of the young
larva enter the fruit at this pomt. In case of very wet weather
it is advisable to give a second spraying about two weeks later
and again early in July. The late spraying is to meet a second
brood of the insects that appear about that time. The first spray-
ing may be of Paris Green or other arsenic poison, the subse-
quent ones with poisoned Bordeaux. Appendix dy

CURCULIO.

This is a small beetle that affects cherries, apples and plums
—notably the last. The adult lays the eggs in a characteristic
erescent-shaped slit in the young fruit, and hence they ean not
be reached by any poison, as they are completely covered by the
fruit when they hatch. The adult beetles have a habit of feeding
on the fruit, however, and some of them may be poisoned with a
Paris Green spray applied just after the blossoms fall. It is also
possible to gather the small beetles by jarrmg them down from
the tree and catching them on sheets spread on the ground. Es-
pecially constructed ‘‘Cureulio Catchers’’ are sometimes em-
‘ployed for this purpose and are made so that they may be moved
from tree to tree. The insects are collected from the sheet and
destroyed.

LEAF EATERS.

There is such a host of leaf eating insects that our space wili
not permit a description of each species that can be found doing
damage to Indiana crops. We will only mention some of the
most common and destructive. Since the treatment for all of
these insects is the same, it will not be difficult to handle any
new problem that may present itself along this line.

TOMATO WORM (Sphinx Moth).

- This sometimes troublesome insect is the larval form of one of
the Sphinx moths. The caterpillar is distinguished by the pres-
ence of a peculiar horn on the tail, which is commonly supposed
to be venomous. As a matter of fact, it is absolutely without
poison of any kind, and the worm can be handled with impunity
by anyone. The insect passes the winter in the resting or pupal
stage in the ground, and many of them will be destroyed by
thorough cultivation. In small gardens where the worms are

doing any considerable damage they may best be removed by
hand picking. Large fields that are badly affected should be

sprayed with Paris Green early in the season before the fruit
attains any size. This will probably remove most of the brood
and make the matter of hand picking the few that remain a com-
paratively easy task. Often this insect is attacked by a parasitic
fly that lays its eggs on the body of the worm and eventually
causes its death. The small cocoons of the fly are sometimes to
be found sticking all over the bodies of the caterpillars. Such
specimens should be allowed to develop, as they are doomed to an
early death, and by allowing the flies to reach maturity an addi-
tional control is placed over the remaining pests. Other forms
of the Sphinx Moth affect different plants. One of them is very
destructive to tobacco, and should be handled just as the tomato
worm is handled.

CATALPA SPHINX.

Quite recently the so-called Catalpa Sphinx has been intro-
duced into Indiana and is causing great damage to the Catalpa
Trees. It seems to be a very thrifty form and is one of the most
difficult to control, owing to the character of the plants it feeds
on. Neither spraying nor hand picking is practical, and the
only method of control seems to be thorough cultivation under
the trees in both late fall and early spring. Unless the insect
can be exterminated in this way it will mean that Catalpa grow-
ing in forest plantations will soon be in the same condition as
Black Locust growing, as the latter tree is thoroughly impractical -
because of the damage caused by the uncontrollable locust borer.

21

SLUGS.

These slimy larvae sometimes become very injurious on cherry
and other trees. They can be destroyed with Paris Green or may
be treated with common lime dusted on dry. Their sticky bodies
hold the lime and they are quickly killed.

' POTATO BUGS.

This insect is so common and so widely distributed that it does’
not require any description. They may be gathered by hand
and destroyed where they are not too thick. This is especially
effective in the early part of the season, and will prevent serious
devastation later in the summer. The standard spray, of course,
is Paris Green.

ELM LEAF BEETLE.
ELM LEAF CATERPILLAR.

Both of these troublesome insects are lable to be met with
in almost any part of Indiana, and should be promptly treated.
The damage is done by the larva of both insects and by the adult
beetles as well. Paris Green sprayed on the trees when the pests
make their first appearance is the only remedy worth consid-
ering.

THE TUSSOCK MOTH.

This troublesome insect is usually periodical in its attacks
on trees, and is making its appearance in dangerous numbers for
the first time in some years.

The moth winters in the egg state, and early in the summer the
young larvae hateh and at once crawl to the foliage and begin
to feed. The eggs are laid by the female moth on the old cocoons,
and as these cocoons are frequently situated on houses and other
objects away from the trees the young can be kept from the foli-
age by banding the trees with some sticky preparation which will
keep them from crawling up the trunk. In the winter the cocoons
bearing egg masses should be collected and burned so as to de-
stroy all the young that are present. A favorite place for the
situation of cocoons is under the overlapping weatherboards on
the sides of houses. In summer, after the caterpillars make their
appearance, they can be destroyed by spraying the trees with

ay

Paris Green solution. This remedy is proving very successful in
Indianapolis, but it must be thoroughly applied, and if washed
off by the rain it should be repeated. The larva or caterpillar
of this moth is one of the most beautiful of all the curious array
of insects. It may be easily recognized by the presence of sev-
eral tufts of white hair on the back, from which it takes its
name of the ‘Tussock Moth. At the head are two long pencils
of brownish hair, with a single similar one on the tail. The
front part of the head is bright red in color and a couple of red
olands occupy segments near the tail. The hairs of this cater-
pillar are barbed, and sometimes cause more or less irritation to
persons of tender skin when they are carelessly handled.

Suggestions’ given for the few forms enumerated above will
suffice to give a key to the treatment required for almost any leaf-
eating insects. Any special forms that may at any time cause
damage should at once be sent to the office of the Entomologist
for identification, and suggestions relative to their treatment
will be sent promptly.

BORING INSECTS.

There are such a host of insects that damage the trees by bor-
ing in their trunks or limbs that it is impossible to more than
mention them in the short space that we have available in this re-
port. One of the most destructive and important from an eco-
nomic standpoint is the Locust Borer, an insect so common and
so widely distributed that locust growing for fence posts is im-
practical over the greater part of eastern America. In Indiana
I have yet to find a locality where the Locust Borer is not firmly
established, and is already doing very great damage to the plan-
tations that have been set out. There is no practical way of con-
trolling this insect, and the only thing to do is to plant other
trees that are not bothered in this way. Other borers affect the
apple, peach and plum among our orchards, and to a certain
extent they may be exterminated by eutting out and burning
the affected trees. Where the cutting and burning is done thor-
oughly there is no reason why this treatment should not be sue-
cessful. I know of an old peach orchard that was badly affected
with the trunk borer when a friend of mine took possession of it.
After three years’ work he has succeeded in exterminating the
borers, and most of the trees are completely recovered from their

23

injuries and are in very fine shape today. Apple borers may
sometimes be very successfully cut out without hurting the tree
greatly. It would also be worth while to experiment with car-
bon bisulphid—pouring some of it into the channels made by the
insects and ‘covering the mouths of the burrows with putty to
keep in the fumes. In France some successful experiments have
been carried on by using a mixture of formaldehyde and gly-
cerine in the same way as suggested for the carbon bisulphide.

In some parts of Indiana. the Elm-tree Borer has done con-
siderable damage, and wherever it makes its appearance it should
be promptly attended to, as it rapidly spreads from one tree
to another and in a short time a large area is worked over and
destroyed.

-Numerous root borers affect different kinds of trees, and some
of them may be gotten rid of by the liberal use of tobacco dust
‘or wood ashes around the roots of the trees. Any of the potash
salts are also valuable in this same connection, and even if they
do not kill the borers they will so stimulate the tree that it may
be able to outgrow the effects of the borer damage.

FUNGUS DISEASES.

In the control of fungus and bacterial diseases it must always
be borne in mind that the trouble is usually transmitted in the
form of very minute spores and any treatment must be thorough
enough to kill all possible chances of any spores living through it.
Often the body of the fungus plant itself is miscroscopic in size
and the spores (which are to the fungus plant exactly as seeds
are to the flowering plants) are infinitely small. In regard to
- many forms of fungal disease our knowledge is still very incom-
plete, but gradually we are finding new remedies for pests here-
tofore considered uncontrollable, and in the future we may ex-
pect great advances along the line of plant pathology. There
are still some forms that do not yield to any treatment. In fact,
it is not definitely known just what is the cause of certain plant
diseases, and for lack of any remedy we can simply use preventa-
tive measures and cut out and burn all affected plants. Peach-
yellow, Black-knot on the plum, Pear-blight, some of the root
galls, and a number of other troubles come in this class on which
scientists are still working.

24

APPLE (Anthracnose).

This disease is caused by one of the fungi in the genus Gloeo- —
sporium, and causes small dark sunken spots in the fruit. It
should be sprayed with Bordeaux both before and after blos-
soming.

SOOTY FUNGUS.

This fungus causes the fruit to appear speckled, as with a thin
coat of soot or fly specks, and is caused by “‘Leptothyrium pomi,”’
a minute fungus. The quality of the fruit is not injured but it
is rendered less marketable. The spraying for Anthracnose will
probably be all that is needed to prevent this disease.

BLIGHT.

The same bacteria that causes the blighting of pear is some-
times responsible for damage to the apple. Affected parts should
be cut out and burned.

APPLE SCAB.

This is a disease that appears at its worst in cool, damp sea-
sons, and at such times it is difficult to control. The fruit and
foliage are both affected and as a result the standing crop is lost
and the crop of the succeeding year prevented by a lack of leaf
work. Early spraying with Bordeaux, as recommended above,
should be effective for this trouble.

BLACKBERRY (Orange Rust).

This common disease of the Blackberry is best controlled by
burning all the affected parts. It is transmitted by the red spores
on the leaves in summer, and any treatment should be very
thorough, or it will be time wasted.

CHERRY (Black Knot. See Plum).
SHOT-HOLE FUNGUS.

This fungus affects the leaves of the cherry and causes them
to become spotted. The spots later turn dark and fall out, giv-
ing the appearance of having been shot with a shot-gun. Dilute
Bordeaux, early in the season, will prove effective.

25

CHERRY ROT.

This is not a common disease in most parts of Indiana, but
it may become very destructive. The fruit is affected and dries
up, often. remaining on the tree until the next season. These
dried fruits are responsible for the fungus living over the winter,
ancdas a means of prevention all affected fruit should be care-
fully gathered and destroyed. Bordeaux should be used before
the blossoms are out.

CUCUMBER (Anthracnose).

Causes circular spots in the leaves to die. Also affects the
stem. Bordeaux will be found effective if the trouble becomes
serious.

WILT.

This is a disease of cucumbers, melons and squashes that is
caused by the presence of a bacteria growing in the tissues of
the plant. The water supply is eventually cut off and the vines
die for lack of moisture. It is a very difficult thing to control
and the only practical treatment is the extermination of the
trouble by gathering and burning all affected vines.

GRAPE.

There is a long list of fungi that affects the grape, and for the
most part our knowledge relative to their identification is not
very definite. Most of them can be prevented by a thorough
] spraying with Bordeaux early in the spring before the buds open
and again after the fruit has set.

. MUSKMELON (See Cucumber).
OATS.

Rust on the oats is rather common during the wet seasons.
It is also usually associated with the presence of the green oat
louse. As a rule it does not do any great damage. There is no
practical remedy.

SMUT.

The smut of oats sometimes causes very serious losses and can
be prevented by using the formalin treatment of the seed. Ap-
pendix (B).

PEACH.

The crown gall of the peach and pear usually oceurs at the
root collar and takes on the form of a large excressence just
below the surface of the ground. As yet we have had but few
reports of it from Indiana, but conditions in other States indi-~
eate that it should be watched for and promptly gore rid of.
The only treatment is cutting out and burning.

LEAF CURL.

During cool, moist springs this trouble on the peach may be-
come very serious. It ean be prevented by early spraying with
Bordeaux before the buds open.

PEACH YELLOWS.

This is a serious disease of unknown cause that must be treat-
ed by the removal and burning of all affected stock. It is char-
acterized by the early ripening of the fruit, which is usually
“off color’’ for the variety; excessive branching of the new
shoots, and the production of bunches of slender, wiry twigs.
The color of the foliage is also usually of a pale, sickly yellow
color. It is one of the most dangerous diseases affecting the
peach.

PEAR BLIGHT.

In this disease the branches wilt and the foliage turns dark
but does not fall from the tree. It is caused by a specifie bac-
teria and is contagious from one tree to another. It can be
checked and eradicated by thoroughly cutting out and burning —
all affected parts.

PLUM (Black Knot).

This disease is caused by a fungus that infests the branches
and causes unsightly exeressences to form along them. It is con-
tagious and destructive but can be controlled by cutting -out the
knots in the winter and burning them.

SHOT-HOLE FUNGUS (See Cherry).
RASPBERRY (Anthracnose).

This fungus is sometimes so severe in its attacks on the rasp-
berry that it renders its successful cultivation practically impos-
sible. It occurs on the young canes as round, purplish spots, and

@

27

winters in the spore condition on the dead wood. Thorough ecut-
ting out of all affected stock and spraying the remainder well
with Bordeaux would probably be effective in checking damage
done by this pest. It is almost impossible to propagate young
plants from stock that is affected with anthracnose, and nurseries
affected with it will not be issued certificates.

WHEAT RUST.

This fungus (Puccinia Graminis) is difficult to control. In re-
gions where it is very common wheat growers are trying to se-
leet varieties of wheat that are rust proof. There are no sug-
gestions as to its control.

STINKING SMUT.

This fungus trouble is sometimes very destructive to wheat,
_ and can be prevented by the formalin treatment as suggested
for oat seed. Appendix (B).

APPENDIX A.

—e.— ——____

BORDEAUX MIXTURE.

Pepe sulphate 4.35. .u=. 2. 2h.se. 16 pounds
EDS) Lia a le DNC a ge oe 4 pounds
TSM RTE as eat ee a ea oe 50 gallons

Dissolve the copper sulphate and the lime in separate vessels,
using a couple of gallons of hot water for each. When dissolved
add the lime slowly to the copper solution and then put in enough -
water to make up the full fifty gallons.

Bordeaux Mixture is not an insecticide at all but is used as a
preventative against fungus parasites. The copper acts by de-
stroying the spores cf the fungus, and the lime helps to make it
stick on the tree. It is often valuable to add Paris Green to the
‘Bordeaux and thus secure effective work against insects as well
as against fungus. For this purpose the Bordeaux solution
should be considered simply as so much water, and the proper
quantity of Paris Green added as directed elsewhere in this bul-
letin. The excess of lime in the Bordeaux will be sufficient to
neutralize the Paris Green.

MAR 2 1908 98

APPENDIX B.
FORMALIN TREATMENT.

Formaldehyde is obtainable in what is known as a 40 per cent.
solution. One pound of this solution should be diluted with 50
gallons of water and the grain well sprinkled with it. The seed
should then be immediately covered with a wet sheet and allowed
to remain for several hours. Allow to dry before planting.

For potato scab this same solution can be used but should be
diluted only half as much. Soak the potatoes for three hours be- —
fore planting.

APPENDIX C.
COAL OIL EMULSION.

The following formula for Kerosene Emulsion is from Prof.
J. B. Smith’s Eeonomic Entomology:

Hard soap, shaved fine! 3.) 2s ena 1% pound
Water i200 Sco 1 gallon
Kerosene’ 60h), . 1 petty cones sae res eae 2 gallons

Dissolve the soap in boiling water; warm the kerosene and
add the boiling hot suds to it; then churn with a forece-pump for
a few minutes and we get first a milky appearance, which yields
rapidly to a cream, and this to a soft butter-like mass. When
cold it will adhere to glass without oiliness, and the emulsion
thus made, containing sixty-six per cent. of kerosene, will re-
main unchanged for some time, and may be mixed with water
to any extent. Soft water must be used for best results, and
with very hard water a real emulsion can not be obtained at —
all without the addition of borax sufficient to soften it. Diluted
from nine to twelve times, this emulsion is very erfective against
plant lice, many scale insects and such others as yield to contact
insecticides in general. Plants vary in their resistance to this
material, not only absolutely, but relatively under different eli-
matic conditions. Diluted nine times, few insects resist its effects
and only the hardier plants can be safely treated ; diluted fifteen
times, only the green plant lice are affected, while some foliage
shows material injury. Where plants do not readily stand a
dilution of twelve times it is better not to use the emulsion at
all. For winter use the emulsion is useless as against dormant
scales, and more injurious to trees than the undiluted oil.

CONGRESS

—ABDRANT UF