THE UNIVERSITY OF KANSAS,

LAWRENCE.

EXPERIMENTAL STATION.

es

FIFTH ANNUAL REPORT OF THE DIRECTOR,

FOR THE YEAR 1895.

F. H. SNOW,
Director.

CONTAGIOUS DISEASES OF THE CHINCH-BUG.

LAWRENCE, KANSAS,
Marcu, 1896.

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CONTAGIOUS DISEASES OF THE CHINCH-BUG.

LAWRENCE, KANSAS,
Marcu, 1896._

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LETTER OF TRANSMITTAL.

LawRENCE, Kas., January 18, 1896.
To His Excellency E. N. Morrill, Governor of Kansas:

In accordance with the requirements of the act making ap-
propriation for the maintenance of the Experimental Station
at the University of Kansas for the promotion of experiments
for the destruction of chinch-bugs by contagion or infection, I
forward to you the following report of the results of the experi-
ments for the year 1895, with an itemized statement of the
money expended in the experiments.

Yours respectfully, F. H. SNOW,

Director of the Experimental Station.

CONTENTS.

PAGE.

ere TOW RANE MED PATS Vr Webel as orl ult oer P uc ee cat ce barca: Deas 2
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REET MENTS IN DER, VARY LO So. ie sete MEELIS 2. vials gis’) «as Mae 7
T.. General Summary of the Year’s: Work. /).{... 2... 5.0.6.0, DL aes i

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HV Eaboratory Experimentss. (ti) ie0 acy Nal WEIN i a a 18

May eela) Hiscperti eon gai kn eh Fi Ne eh Mo SY ae 27

Wi) eld ‘Observations of MM. A’. Barber}. i300 6 oo s Gk is Po oe 34

VII. Field Observations-of W. W. Brown in Coffey County............. 39
VIII. Considerations Regarding the Status of Sporotrichum............. 41
bX The Barrier Methods yay wee poles ete hae ook Sok Lec hea ai 44

X. Summary of Infection Distributed in 1895................... 000... 49
UATE MENT LOM TP RNDTDIRES v Ae ciel Senvae Ley cin ers ethers heck ol. eee 51
DIRECTIONS FOR OBTAINING AND APPLYING THE INFECTION ................ 53

INTRODUCTION,

Durine the year 1895 both field and laboratory experiments
have been conducted on a large scale for the purpose of solving
doubtful points concerning the contagious diseases of the
echinch-bug. Many thousands of farmers have been supplied
with the Sporotrichum, or white-fungus infection. Their re-
ports in reference to the success of the field operations have
been of conflicting character as in former years, but the major-
ity maintain that great benefit has been derived from the use
of the infection. —

It has been thought desirable to devote this report chiefly to
a detailed description of the laboratory and field investigations
conducted under the supervision of the Director by his able
staff of associates and assistants. Especial acknowledgments
are due to Associate Professor W. C. Stevens and Assistant M.
A. Barber, of the Department of Botany of the University of
Kansas, and to Mr. F. E. Marcy, for their unremitting vigi-
lance in laboratory and field and for their invaluable services
in the preparation of this report.

Attention is here called to the fact that the Sporotrichum or
white fungus evidently survived the winter of 1894—’95 in the
field over an extended area of the state, and artificial infection
was therefore not so essential as in years when it did not sur-
vive the winter. Whether this widely-extended natural presence
of Sporotrichum was the result of the general introduction of
the infection throughout the state in 1894 from the laboratory
of this Station, it would not be possible with certainty either to
affirm or to deny.

Attention is also called to the fact that the weather conditions
of the past two years have been highly favorable to the undue
multiplication of chinch-bugs and to their successful hiberna-
tion inimmense numbers. The rainfall for the first five months
of 1895 at the University was smaller than in any season during

6 Contagious Diseases of the Chinch-bug.

the past 28 years, not excepting the phenomenally dry season
of 1874. This extreme dryness was unfavorable to the propa-
gation in the field of the diseases which destroy the chinch-bug,
whether these diseases were artificially introduced or naturally
present. The early wheat harvest consequent upon the spring
drouth precipitated the chinch-bugs upon the corn while it was
very young, so that a greater injury was inflicted by the bugs
than if the plant had been of its usual size and vigor. At the
same time the conditions favorable to the growth of the Sporo-
trichum were not present, and the bugs were practically unhin-
dered in their work of destruction. Later in the season the
conditions were favorable for the development of the fungus,
and the chinch-bugs were destroyed in immense numbers. Yet
immense numbers remained alive, and in many cases continued
to damage crops.

The experience of the year 1895 corroborates the conclusion
of former years that Sporotrichum cannot be depended upon to
do efficient work unless the proper conditions exist for its
development. The presence of these conditions insures the
extended destruction of the chinch-bug, but will not secure
its annihilation. The absence of these conditions often ren-
ders it desirable to adopt some other measures for relief.
Hence, considerable attention has been given to the use of the
‘‘barrier method’’ for keeping the bugs from gaining entrance
to the corn-fields from the wheat stubble. The wise farmer will
keep his fields supplied with infection, and will also be on the
alert to employ mechanical means to prevent the bugs from
entering the corn-fields. The two methods combined will insure
a greater amount of protection than either method alone.

The proposed method of inoculating the bugs in the field by
spraying them with artificial cultures of the spores of Sporo-
trichum has not yet proved successful, and we still depend upon
the original plan of introducing the disease by scattering the
dead bugs covered with the spores of the fungus.

EXPERIMENTS IN 1895.

I.—GENERAL SUMMARY OF THE YEAR’S WORK.
1.—THE CHINCH-BUG AND THE WEATHER.

The winter and spring months of 1894 and 1895 were un-
usually dry, and furnished excellent conditions for the hiberna-
tion of chinch-bugs, and in consequence they have been present
‘in Kansas in large numbers during the past two years. The
two successive favorable periods of hibernation resulted in a
much larger number of bugs in 1895 than in 1894. We infer
that the periodic appearance and disappearance of chinch-bugs
_ in a locality is largely due to favorable or unfavorable con-
ditions for hibernation in that locality. A wet fall, winter
and early spring are pretty certain to result disastrously to the
bugs. If there be a succession of such periods the chinch-bugs
practically disappear. ‘There are always some survivors, how-
ever, and a brief succession of dry hibernation periods results
in their rapid increase. It is probable that the disappearance
of bugs during wet hibernation periods is due to the ravages of
_ diseases, but of this we have as yet no certain proof.

2.—SPOROTRICHUM AND THE WEATHER.

The dependence of Sporotrichum upon the weather has been
more evident this year than ever before. We have had a sea-
son of extremes, a very unusual dry spell with clear skies dur-
ing the three spring months, followed by heavy and frequent
rains and cloudy skies for the three summer months. A some-
what detailed statement of the weather conditions will be of
service here, and since the character of 1894 probably had some
influence on the number of bugs in 1895, the statement will
include 1894.

During the 12 months preceding January, 1895, the rainfall
was 6.06 inches below the average of the preceding 26 years.
From January 1, 1895, to June 1, the rainfall was 5.11 inches
below the average of the same period in the preceding 27 years,

(7)

8 Contagious Diseases of the Chinch-bug.

and for the 17 months preceding June 1, 1895, the rainfall was
11.17 inches below the average. The deficiency of precipitation
continued through January, February, March, April, and May,
1895. During the same period the relative humidity was also
low: For January, 1894, the relative humidity was 3.8 above
the average; February, 1.2 below; March, 6.3 below; April,
8.6 below; May, 10.0 below; June, 5.0 below; July, 13.32 be-
low ; August, 15.06 below; September, 3.6 below ; October, 7.4
below ; November, 9.2 below ; December, 7.2 below; January,
1895, 7.0 below ; February, 1.1 above; March, 9.8 below; April,
11.4 below; May, 8.8 below.

So that during this period the conditions were apparently
unusually poor for the development of Sporotrichum, and un-
usually good for the safe hibernation of the bugs and their sub-
sequent increase in the spring. The meteorological conditions
just enumerated also had their effects upon the crops. Winter
wheat made a spare growth and ripened early, and the bugs
left the wheat for the corn while the latter was comparatively
small. The ground was'dry at this time, and the young corn,
unable to stand even a small loss of water, succumbed to the
myriads of bugs that swarmed in from the fields of small grain,
At this time very little Sporotrichum could be found in the
fields except in specially favorable localities, even where our
best efforts were made to introduce the disease artificially. This
could not be due to the fact that virulent infection was not
present in the fields, for when bugs were taken to the labora-
tory and put into jars where the conditions for the growth of
the Sporotrichum were kept constantly good, they died and
their bodies were covered with an abundant growth of Sporo-
trichum.

The bugs entered the corn-fields in this locality about the
first of June in numbers larger than had been known to us at
this season in former years. At this time Sporotrichum had
made only a scanty growth in most fields, and the older bugs of
the first brood were well along toward maturity. The first ma-
ture bugs were seen by us 10 days later. On the last day of May
1.46 inches of rain fell, this being the first copious downpour
of the season. Earlier rains had occurred, but they were incon-
siderable and did not suffice to keep the ground moist long
enough to start Sporotrichum extensively in the fields. Follow-

Fifth Annual Report. 9

ing this date there was very little precipitation until the 9th,
10th and 11th of June. On these three dates there was almost
a continuous shower amounting to 2.71 inches. Other rains
followed on the 12th, 14th, 17th, and 18th, adding 2.21 inches
to the rainfall. The average relative humidity for the first
eight days of June was 58.8, while the succeeding eight days
had an average relative humidity of 77.7. This increased |
humidity and precipitation was followed by an epidemic of
Sporotrichum, and fungus-covered bugs were found in abun-
dance in this locality in all fields visited.

The rainfall and average relative humidity for the spring and

Relative

Rainfall. humidity.
14S OLAS oe Ct Ueno a | I etc 1.47 56.90
JSTOR TORU hs sia Uo COMER A OES eae eR) LAVAS ck Ib te cet MAG a Le 0.74 57.06
UME erates 2 tek Teter, Mae eae BUac tan ality tN oo) 3.65 60.04
DIPS SEO OS USI cen Mr A) A UG 1S el as ata ae ull He REN 5.93 68.20
“LRA cic tie BS nee a en Ue desta GR It oo TR CUBAN Ue Le 10.06 77.70
JAAUROM TIS Fy SNR Re a eg a ee ee EA DRI NET OL CY SL NL oe ea ay 12.30 79:40

It is seen that the rainfall and humidity increased from month
to month. Sporotrichum continued throughout the summer,
with brief intermissions.

3.—EPIDEMIC OF SPOROTRICHUM AND EMPUSA.

On the 17th of June Mr. Barber found in Coffey county chinch-
bugs which had been killed by Empusa, and on the 6th of July
Mr. Marcy found chinch-bugs dead with Empusa in large num-
bers in corn- and millet-fields in Douglas county, and at times
during the summer Empusa was even more destructive of the
bugs than Sporotrichum. This was particularly the case later
in the summer when the ground was kept wet by continuous
heavy rains.

We have never before witnessed such a wide-spread epidemic
of Sporotrichum and Empusa as occurred this season, but the
necessary amount of humidity came too late in many localities
to start the fungus diseases extensively in time to help the
young corn at that critical time when the bugs were invading
it from the small-grain fields. The diseases must have been
naturally epidemic when they appeared extensively later, be-
cause we could see no difference between the fields inoculated
artificially and those not inoculated, and bugs received from

_

10 Contagious Diseases of the Chinch-bug. ;

various portions of the state very frequently developed the dis-
ease under proper conditions without artificial inoculation.

4.—HEAVY RAINS AND THE CHINCH-BUG.

The heavy, beating rains of the summer months enabled us
to see more certainly than ever before that rains do not in them-
selves destroy chinch-bugs in sufficient numbers to saye the
crops. The disappearance of the bugs so often noticed after
heavy rains is probably not so much due to the beating of the
storm or the drowning of the bugs as to the progress of fungus
diseases which may spring up naturally, as was noticed this
year, when the ground is moist and the atmosphere is humid.

5.—RELATION OF SOIL, DRAINAGE, ETC., TO FUNGUS DISEASES.

After Sporotrichum and Empusa became established in the
fields, the best results were noticed where the grain made the
densest growth and where the ground was kept shaded and
moist thereby. In many such situations the ground was fairly
well covered with fungus-covered bugs. But in those fields
where the stand of grain was thin and the soil subject to rapid
drying, relatively fewer fungus-covered bugs could be found.
The growth of the Sporotrichum and Empusa was also found
to depend on the character of the soil and the natural drainage
of the fields. Where the soil was clayey and subject to baking
on the surface, the fungus was comparatively infrequent, but
where the soil was friable and loose in other parts of the same
field the fungus was prevalent. Elevated portions of a field
were found to be less favorable to the growth of the fungus than
lower-lying portions which were moist for a longer period. In
some instances, the difference was so great as to amount to com-
plete failure in the less favorable situations, so far as the eco-
nomic value of the disease was concerned, while in the more
favorable places in the same field the destruction of the bugs
was sweeping and positive.

It would appear from certain experiments that the ability of
the. Sporotrichum to destroy bugs depends in some measure at
least upon the condition of the bugs; but the elements of the
problem are so complex that it is difficult to arrive at definite
conclusions. It seems certain that bugs which have about run
their life course succumb more readily than the younger and

Fifth Annual Report. a

stronger bugs, but we have known the bugs in the larval state
to die quite as rapidly as the more mature bugs. Mature bugs
of the second brood in autumn and late summer show a remark-
able resistance to the disease, but these yield to the disease
after long confinement in the laboratory, and probably also in
the field during the hibernation period if the meteorological con-
ditions are favorable.

6.—ARTIFICIAL CULTURES.

This year, in addition to our old method of carrying on arti-
ficial infection by fungus-covered bugs, we have used artificial
cultures of Sporotrichum on various media, particularly on
steamed potatoes and whole corn. The cultures were shaken
up in water, and the water was applied by means of spraying
machines. Experiments with this and with the old method
gave contradictory results in the laboratory, but in the field we
were unable to see any difference between the treated and un-
treated fields, either when fungus-covered bugs or artificial cul-
tures were used for infection, excepting in one experiment at
the very outset of the year’s work; that is to say, during the
spring months, when the weather conditions were unfavorable
for the growth of Sporotrichum, the artificial dissemination of
spores produced no results, while later in the season, when the
conditions were more favorable, we found Sporotrichum abun-
dant in the untreated as well as in the treated fields.

7.—THE BARRIER METHOD.

Since the experience of the past five years has taught us that
there are always to be expected a varying percentage of failures
in the use of Sporotrichum, we strongly urge that the farmers do
not put their sole dependence upon this method, but that they
also adopt the barrier method described later in this report.
We have experimented the past season with this method suffi-
ciently to be assured that it is a trustworthy defense at that
very critical short period when the bugs are passing from the
small grain into the corn-fields. With the plan of defense
mapped out further on it should be the settled policy of the
farmers not to let the bugs enter the corn. While the bugs are
yet in the wheat and after they have scattered in the corn, and
later when they have gone into winter quarters, almost our only

ad

12 | Contagious Diseases of the Chineh-bug.

hope is in the diseases which we know to be destructive to the
bugs under proper conditions. How much relief is to accrue to
the farmer from the ravages of these diseases cannot be pre-
dicted beforehand, on account of the complexity of circum-
stances which affect them. It is simply acting the part of
wisdom, however, to see that the germs of disease are present
in the field.

8.—_WATCHFULNESS NECESSARY.

In using either infectious diseases or the barrier method it is
important to know at an early date whether there are bugs
present in the small-grain fields. As soon as the ground is
thawed in the spring search should be made for the bugs under
stones and debris, and at the roots of grasses and small-grain
plants. If bugs are present Sporotrichum should be scattered
at once. Too frequently the farmer becomes aware of the
presence of chinch-bugs when he is cutting his small grain, or
when the bugs are swarming into the corn-field or have already
taken possession of it. When we consider the tremendous |
losses annually due to the ravages of the chinch-bug, and the
possibilities, with our present knowledge, of preventing the
larger part of these losses with proper foresight and care, we
are convinced that no labor by the farmer is so well paid as
that spent in protecting his crops from these pests.

9.—UNITED EFFORT NEEDED.

The farmers should organize in every community, and fight
the chinch-bug in an intelligent and systematic manner. This
is a common cause and should have united effort.

Early in the fall the farmers about Mulvane, in Sedgwick
county, organized an anti-chinch-bug association, and are ready

‘for concerted action in the spring. If their example were fol-

lowed throughout the state the chances of success would be
greatly increased. At the close of this report we will outline a
plan of defense suited to individual and concerted action.

Fifth Annual Report. 13

Il.—THE CHINCH-BUG AND ITS DISEASES.

We believe it will be of service to our readers to preface the
report of the work of the past year with a brief discussion of
the life history of the chinch-bug and the fungus diseases which
are known to destroy it. What we have to say will be in part
a repetition of some things already published by us, but since
the larger number of those who receive the report this year
may not be acquainted with our previous reports the repetition
is warranted.

1.—_LIFE HISTORY OF THE CHINCH-BUG.

The appearance of the adult chinch-bug is already too well
known to our readers to require a description.

Adult chinch-bugs pass the winter under the shelter of leaves,
sticks, stones, clods, corn-stalks, roots of grasses, etc., and are
able to live through a temperature below freezing. They have
been found to survive after having been frozen up solidly in ice.

They begin their depredations on the roots of small grains as
soon as the weather opens up in the spring. Here the female
soon commences to deposit her eggs, continuing the operation
over a period of 20 days, and depositing about 300 eggs in all.

The egg is only about 53, of an inch long and about one-fifth
as wide, and is easily overlooked by the naked eye. The egg is
at first creamy white, but changes to reddish as the embryo de-
velops. Theeggs hatch out in about two weeks, and the young
larvee, begin to feed at the roots or upon the stalks of the small
grain almost immediately. The chinch-bug arrives at maturity
in from five to seven weeks, and in this interval it sheds its skin
four times. After hatching the bug is of a pale reddish color,
and grows darker after each successive moult. Up to the time
of the third moult the bug is said to be in the larval stage ; after
the third moult it is in the pupal stage, and after the fourth
moult it is in the imago or mature stage. The chinch-bug does
not have wings until the last or fourth moult. When the mature
bug emerges from its last moult it is of a pale pink color, but in
a few hours it changes to a blackish color. The same thing is
observed when the larva sheds its skin for the third time and
passes into the pupa state. The pink, freshly-moulted bugs
have often been mistaken by farmers for diseased bugs.

14 Contagious Diseases of the Chinch-bug.

t
The following observations made by Mr. Barber on the color
changes of chinch-bugs will be of interest here :

August 19. Chinch-bugs in a millet field near the University
were seen to be piling up especially about bases of tufts of millet
or grass. Bugs seem to be mostly brown and black, with some
pink ones. These proved to be those which had newly moulted
from the larval to the pupal stage and had not yet turned black.
Morning cloudy and cool, rainy later in forenoon. Pink or
flesh-colored bugs, the pupe freshly moulted from larval stage,
were taken to the laboratory and put into test tubes in several lots.
In one tube only those which were moulting or had scarcely
scarcely finished were used. Bugs put in from 12 mM. tol P. M.
At 3:30 Pp. M. all lots had changed to a black color. Two lots
which had been kept in a dark place'during all this time were
also black. Later experiments with a bug which was put in a
tube just at its moulting time shows that the change in color
may occur in two hours or less. Some larve were put into a
dark closet on afternoon of August 19. August 20 in the morn-
ing several were found to have moulted and the pup were black
as those kept in the light. So it appears that the coloration
takes place in darkness as well asin daylight. One pink bug
was killed with ether on afternoon of August 19, and color was
found unchanged, 7. e., still pink on morning of 20th. It is evi-
dent that in this field at least there was a characteristic bunch-
ing and moulting stage preceding the black pupa stage. Moults,
or what appeared very much like them, were found very much
earlier in rolled-up leaves of millet where only young red bugs
were present. Eggs were found in the same places.

August 20. A bug was put into a test tube when: moulting
from larval stage.

9:07 a4.m.—Pink bug, partly out of brown skin.

10:07 4. m.—Bug much darker in color.

10:50 a. m.—Bug black.

September 16. A bug in the pupal stage, just moulting to the
adult stage, at 11 A.M. was put intoavial. At 12:55 p.w., the
black spots on the wings were as distinct as in old adults, and
the body was becoming brownish. At 2 p.m. the body was
deeper brown. At 8 A.M. of the following day the bug had the
characteristic of the old adults.

Fifth Annual Report. 15

Before the bugs of the first brood are all mature, and while

many of them are even in the larval state, they leave the

fields of small grain and swarm over into the fields of young
corn. The mature bugs seldom fly at this time, and this makes
it possible to easily prevent the bugs from entering the fields
by the barrier method described later in the report. When
the bugs are casting their skins they have the habit of gather-
ing together in piles under clods and fallen corn-stalks, etc., and
since they cast their skins at four different periods of their life
and the eggs are laid through a period of 20 days, the bugs may
be found of all ages in these piles. The bugs in the piles have
often been mistaken for diseased bugs, and we wish to caution
our readers against such a mistake. The shade and moisture
which the bugs seek at this time no doubt aid in softening the
skins so that they may be more easily broken and cast off, and

very likely the trampling of the bugs over each other in great

numbers also assists in the process of moulting.

The bugs emerge from their skins through a slit down the
back just behind the head, and when the bug has emerged, the
empty skin is a complete one.. The slit through which the bug
has crawled often closes up entirely, and then the skins are
easily mistaken for dead bugs. Their character may readily be
determined, however, for if they be taken in the hand and
gently breathed upon they are blown away because of their ex-
treme lightness.

The farmers are often deceived by another habit of the bugs:
When the bugs first enter the corn they mass upon the first few
rows. At this time their great number is most striking, but in
a few days they may scatter widely over the fields, and even
though they are not being destroyed by disease their numbers
may appear to be essentially reduced.

We must repeat what we have said in a previous report, that
the only certain evidence to the farmer that the bugs are being
destroyed in his fields by Sporotrichum is the presence of the
dead bugs covered with the dense white spore-bearing growth .
of the fungus. The reports of farmers to the Station will be
greatly enhanced in value if the above sources of error are care-
fully borne in mind.

.

i

16%: Contagious Diseases of the Chinch-bug.

2.—SPOROTRICHUM AND EMPUSA.

The causes of the known diseases of the chinch-bug are
minute plants known as Sporotrichum and Empusa, or more
popularly as the white and gray fungus or muscardine, respec-
tively. They consist essentially of minute thread-like roots
which penetrate the body of the bug and feed upon it, and the
very minute branches produced on the outside of the bug and
bearing small bodies in great abundance called spores. These
spores germinate and produce new plants, thus serving the
same purpose as the seeds of the higher plants.

The spores are borne in minute bunches on the external
branches somewhat like bunches of grapes. A single spore is
only about ;>45> of an inch in diameter, and there are count-
less numbers of these borne over the body of a single bug.

Empusa, or the gray fungus, does not bear its spores in
bunches, but singly, on comparatively large branches.

These parasitic plants are called fungi, (singular, fungus,)
and are not very distantly related to the rust of wheat and the
mildew of potatoes, grapes, etc.

It is seen that while some species of parasitic plants, such as
wheat rust, potato mildew, etc., injure the farmer by destroying
his crops, other species, such as Sporotrichum and Empusa, are
helpful in that they destroy insects which eat up his crops.
These low forms of plants flourish best in a humid atmosphere
and in moist situations. They are even more sensitive to vari-
ations in the weather than higher plants, because of their very
diminutive size.

With these considerations in mind it becomes evident that
there can be no hope for success with Sporotrichum while the
weather continues dry and hot, while on the other hand the
very diminutive size of the spores and the vast numbers that
are produced on a single bug would lead one to expect their
very rapid and extensive dissemination when once present in a
locality, and a general destruction of bugs when the conditions
are favorable is therefore not surprising.

During the past season we have found Empusa at times quite
as destructive of chinch-bugs as Sporotrichum, indeed, later in
the summer when the weather became excessively wet and
cloudy, Empusa prevailed in some localities to the exclusion of
Sporotrichum ; but Empusa cannot be so much depended on

oe sce

Fifth Annual Report. A

as Sporotrichum, and while it naturally does a great service
at times, we have not found it feasible to attempt its artificial
dissemination.

Sporotrichum seems to flourish through a wider range of
meteorological conditions than Empusa, and would be the more
likely to appear as a natural epidemic.

III,—ARTIFICIAL CULTURES.

We have attempted at various times since 1889 the culture of
Sporotrichum on other media than the chinch-bug, such as po-
tatoes, corn, beef-broth, etc., in the hope of producing the
fungus in greater quantities, and of disseminating the infection
more rapidly than is possible by means of fungus-covered bugs.
These experiments had been confined to the laboratory, and had
not given promising results. We determined at the beginning
of the past season’s work to carry on experiments of this kind
on a large scale in the open field, and at the same time to con-
duct parallel experiments in the laboratory. Pint Mason fruit-
jars were used in making the artificial cultures. A three-fourths
inch hole was cut in the metal cover, and a zinc tube of the
diameter of the hole was inserted into this and soldered flush
with the upper surface. This is essentially as figured and de-
scribed by Forbes, in Bulletin No. 58, issued March, 1895, the
only difference being that we have the tube project into the jar
instead of above it for convenience in sterilizing large numbers of
jars at one time. Whole corn or sliced raw potatoes were put into
these jars, the tubes were tightly plugged with baked cotton,
and the jars were placed in a large steamer and steamed for two
hours in the morning and two hours in the evening for three
successive days. Then, with the usual precautions, the cotton
plugs were withdrawn, and spores from pure plate cultures
were inserted through the tube in cover and dusted over the
corn or potato by means of a piece of platinum foil melted into
the end of a glass rod. This was sterilized in the flame of a
Bunsen burner at frequent intervals. In this manner we were
able to prepare large quantities of material for our field experi-
ments.

To distribute the infection in the fields water was shaken up
with the cultures in the jars. The water ina single jar holding

—2

18 Contagious Diseases of the Chinch-bug.

the spores in suspension was poured into 10 gallons of water and
distributed over the fields by means of a spraying apparatus. It
was found that by this dilution one or more spores could be found
in a single drop of the water. The experiment was varied by
sprouting spores over night in a sugar solution before spray-
ing. At the same time experiments of a like nature were car-
ried on in the laboratory. For this purpose flower-pots half
filled with friable garden soil and closed at the top with cotton
batting were sterilized in a hot-air oven. The soil was then
wet with boiled water, then the bugs were put into the pots,
then the infection, and finally the sterilized cotton was tied
over the mouth of the jar. Bugs from one locality only in
most instances were used in a single set of experiments. An
account of the laboratory experiments will be briefly stated.

IV.—LABORATORY EXPERIMENTS.

Kxperiment 1. March 19 eight pots were started, haying
been prepared as stated above.

(a) Two pots were watered with boiled water, but left unin-
oculated, to serve as checks.

(b) Two pots were infected with fungus-covered bugs.

(c) Two pots were sprayed with culture from potato.

(d) Two pots were sprayed with culture from potato after
the spores had been sprouted in sugar solution.

The bugs slowly died of Sporotrichum in all the pots, the
checks showing no material difference. |

Hxperiment 2. April 22 bugs that had been received from
various parts of the state were put into a large box until they
had intermingled and then were distributed as equally as pos-
sible among 12 pots.

(a) Three were left uninoculated as checks.

(b) Three were inoculated with fungus-covered bugs.

(c) Three, were sprayed with spores of artificial culture on
turnip.

(d) Three were sprayed with sprouted spores from turnip
culture.

Bugs in all the pots slowly died of Sporotrichum, the checks
showing no essential difference.

Es
‘
1.
a

Fifth Annual Report. 19

Experiment 3. April 24 nine pots were started.

(a) Three checks.

(b) Three sprayed with artificial culture.

(c) Three treated with a parasitic fungus found on other in-
sects.

The bugs died slowly in a and ¢ but about twice as rapidly
in b.

Experiment 4. May 2, mixed bugs from various sources were
put into nine pots.

(a) Three checks.

(b) Three sprayed with artificial culture of Sporotrichum.

(c) Three inoculated with Sporotrichum on chinch-bugs.

The bugs remained alive in a, but died in b and ¢ of Sporo-
trichum. The bugs were left in a until all died, but none de-
veloped Sporotrichum.

Experiment 5. May 9, started nine pots.

(my Pbiree checks.

(6) Three sprayed with artificial culture.

(c) Three with Sporotrichum on chinch-bugs.

The bugs died in all the pots, and developed Sporotrichum.

Experiment 6. May 10, started nine pots.

(a) Three checks.

(b) Three sprayed with artificial culture.

(c) Three sprayed with Sporotrichum on chinch-bugs.

The pots were opened May 30, 20 days after inoculation.
The bugs were dead in all the pots. In pots ano Sporotrichum
was present; in pots ) and ¢ Sporotrichum was abundant.

Experiment 7. May 16, started six pots.

(a) Three checks.

(b) Three sprayed with artificial culture.

Sporotrichum developed in both a and b.

Experiment 8. May 16, started four pots with bugs from Ax-
tell, Kas.

(a) Two checks.

(b) Two sprayed with artificial cultures of Sporotrichum.

Sporotrichum developed in a and b alike.

Experiment 9. May 21, started four pots.

(a) Two checks.

(b) Two sprayed with artificial cultures of Sporotrichum.

Sporotrichum developed in a and b alike.

20 Contagious Diseases of the Chanch-bug.

Experiment 10.. May 22, started four pots.

(a) Two checks.

(b) Two sprayed with artificial cultures of Sporotrichum.

Sporotrichum developed alike in a and b.

Experiment 11. June 7, started nine pots with bugs from Lib-
erty, Kas.

(a) Three checks.

(b) Three sprayed with sprouted spores of artificial culture
of Sporotrichum. i

(c) Three inoculated with Sporotrichum on chinch-bugs.

An abundance of Sporotrichum developed in b and c¢, but a
was entirely free from it.

Experiment 12. June 8, started six pots.

(a) Two checks.

(b) Two with Sporotrichum on bugs.

(c) Two sprayed with artificial cultures of Sporotrichum.

Bugs died in all the pots, covered with Sporotrichum. One
of the check-pots showed no fungus for about 10 days, but
finally this also developed Sporotrichum.

Experiment 13. June 10, started nine pots with bugs from
Independence, Kas.

(a) Three checks.

(b) Three with Sporotrichum on bugs.

(c) Three sprayed with artificial cultures of Sporotrichum.

Bugs died and were covered with Sporotrichum in all pots
alike.

Experiment 14. June 12, started six pots with bugs from
Girard, Kas.

(a) Two checks.

(b) Two sprayed with sprouted artificial culture of Sporo-
trichum.

(c) Two with Sporotrichum on bugs.

Sporotrichum developed in all pots alike.

Experiment 15. June 14, started nine pots.

(a) Three checks.

(b) Three with Sporotrichum-coyered bugs.

(c) Three sprayed with artificial culture of Sporotrichum.

Sporotrichum developed in all pots alike.

Experiment 16. June 17, started six pots.

(a) Two checks.

.

a yee ee

Fifth Annual Report. 21

(b) Two sprayed with artificial cultures.
(c) Two with Sporotrichum on bugs.
Sporotrichum developed in all pots alike.

Experiment 17. June 19, started nine pots with bugs from

Glasco, Kas.

(a) Three checks.

(b) Three sprayed with artificial culture.
(c) Three with Sporotrichum on bugs.
Sporotrichum developed in all pots alike.
Experiment 18. June 22, started six pots.
(a) Two checks.

(b) Two with sprouted artificial cultures.
(c) Two with Sporotrichum on bugs.
Sporotrichum developed in all pots alike.
Experiment 19. June 28, started nine pots.
(a) Three checks.

(b) Three with dry spores from artificial cultures.
(c) Three with Sporotrichum on bugs.
Sporotrichum developed in all pots alike.
Experiment 20. July 1, started six pots.
(a) Two checks.

(6) Two with Sporotrichum on bugs.

(c) Two sprayed with artificial culture.
Sporotrichum developed in all pots alike.
Experiment 21. July 5, started nine pots.
(a) Three checks.

(b) Three with Sporotrichum on bugs.

(c) Three dusted with dry spores from artificial cultures.
Sporotrichum appeared in all pots alike.
Experiment 22. July 9, started six pots.
(a) Two checks.

(6) Two with Sporotrichum on bugs.

(c) Sprayed with artificial cultures on corn. Most of the
bugs were pupe.

Sporotrichum developed in all pots alike.
Experiment 23. July 20, started nine pots.
(a) Three checks.

(b) Three sprayed with artificial cultures.
(c) Three with Sporotrichum on bugs.

22 Contagious Diseases of the Chinch-bug.

Two of the a pots showed a decided growth of Sporotrichum,
while one of a and all of b and ¢ did not show any fungus.

Experiment 24. September 6, experiment to determine the
effect of temperature on infectious diseases of chinch-bugs.
Three pots with bugs sent in by express had Sporotrichum
added, and were put into a refrigerator. Three pots, similarly
arranged, were put into a Wardian case at room temperature.
Experiment started 12 to 12:15 p.m. The temperature was
taken with a Centigrade thermometer.

September 7—11:15 a. m.: Wardian case, 24.5°; refrigerator, 13°.

September 7— 2:45 p.m.: Wardian case, 25°; refrigerator, 11°.

September 7—5:00 p.m.: Wardian case, 24.5°; refrigerator, 10.75”.

September 8—10:00 a. m.: Wardian case, 24.5°; refrigerator, 11.5”.

September 9—7:30 a. m.: Wardian case, 23.5°; refrigerator, 12°.

September 9—5:25 p. m.: Wardian case, 22°; refrigerator, 11.75°.

September 10—7:35 a. m.: Wardian case, 26°; refrigerator, 12°.

Bene 10—7:35 a.M.: One pot of each lot was opened; no disease was
noted.

September 12—4:25 p.m.: Very hot afternoon; Wardian case, 31°; refrigera-
tor, 13° to 14°, probably 14°.

September 13—9:15 a.m.: Wardian case, 28.5°; refrigerator, 16°.

September 14—10:15 a.m.: Wardian case, 29°; refrigerator, 14°.

September 16— about 8:30 a.m.: Refrigerator, 16.5°. (Supply of ice small.)

Pots taken out September 23; few bugs alive. Not much
trace of disease, and-no noticeable difference between bugs kept

in refrigerator and those in Wardian case pots.

Experiment 25. September 30. Bugs taken from millet and
corn were put into five pots, three containing wet earth, and
two dry. All were infected with Sporotrichum, the experiment
being merely to determine the relative resistance to diseases of
bugs taken at this period. Dirt was not sterilized. Pots were
put into a close dark place —a refrigerator without ice.

October 16— Pot A, wet: Five Sporotrichum bugs seen
with perhaps 40 to 50 still living and apparently healthy bugs.
Interior of pot moist, and more water, not distilled or sterilized,
was added.

October 16— Pot B, dry: Two or three Sporotrichum bugs
seen. Growth on these not so large as on those in wet pot.
May have been a few more Sporotrichum-covered bugs in the
pot, but number proportionately very small. Fifty to 100 live
bugs roughly estimated. Pot was left dry.

October 16—Pot C, wet: Three, very probably Sporotrichum,
bugs seen. If others were present they were very inconspicu-

Fifth Annual Report. 23

ous. Small clods, etc., were overturned in the search for
Sporotrichum. Pot was freshly watered. About 50 apparently
healthy bugs, roughly estimated.

October 16 —Pot D, wet: Five apparently Sporotrichum bugs
seen. Sixty living, roughly counted. Pot freshly wetted as in
A and C, but much more liberally.

October 16—Pot E, dry: Proportion of Sporotrichum-covered
bugs to living about the same as in other pots, possibly one or
two more with Sporotrichum, but lesser growth in dry pots
makes rough estimate less accurate. Pot not watered. Sporo-
trichum bugs were not removed from the pots.

Pots examined again on October 31. Sporotrichum bugs left
in pots as before on October 16.

Pot A, wet: Still moist. Perhaps 12 bugs dead with charac-
teristic Sporotrichum color, one at least dead with no mouldy
covering. Numbers still living and active, but owing to clods,
etc., in dirt, not easy to count. As many alive as dead, or more
apparently. Pot watered again with distilled water.

Pot B, dry: Some alive but more dead. Few of the dead
ones shew the characteristic mould. Pot left dry

Pot C, wet: Earth not very moist, cracked in pot. Hardly
10 white bugs seen. Many, far outnumbering dead, alive and
active, apparently in healthier condition than in dry pot B.
Pot rewatered. ,

October 31—Pot D, wet: Conditions about the same as in
C, except pure Sporotrichum bugs; hardly more than on Oc-
tober 15. Earth still moist, but cracked somewhat; few live
bugs and no Sporotrichum found in cracks below surface of
soil. Pot rewatered more liberally than were others.

Pot E, dry: Conditions resemble those in other dry pot, B.
Many bugs alive, and lively enough when sun strikes them.
Many dead without characteristic Sporotrichum growth. One
or two with Sporotrichum-like covering. Pot left dry.

November 16— Pot A, wet: Six bugs or so alive. About 40
with the white growth. Pot rather dry, freshly moistened.

November 16— Pot B, dry: Bugs all dead apparently, but
none with white growth on surface of body. (One exception?)
Pot left dry.

' November 16—Pot C, wet: At least 12 living bugs, appar-

24 Contagious Diseases of the Chinch-bug.

ently healthy. Hardly as many with white growth. Earth in
pot moister than in A. Pot freshly moistened.

November 16— Pot D, wet: Number of living bugs appar-
ently greater than in C, and mould-covered bugs fewer if dif-
ferent. Pot freshly moistened.

November 16— Pot E, dry: Bugs apparently all dead; some
with mould covering.

December 5—Pot D, wet: No live bugs seen. Contents of
pot dry. Several dead bugs with no external growth. Pot not
moistened further.

December 5—Pot A: No live bugs seen. Pot dry. Major-
ity with white growth. Pot not watered again.

December 5—Pot C: Same as A. Some live bugs found in
wet pots as late as November 22.

It will be noticed that the checks remained pure in experi-
ments 4, 6, and 11, the bugs dying in the inoculated pots of
Sporotrichum, while in all the other experiments the checks
showed as good growth of Sporotrichum as the inoculated pots.

Experiment 23 showed the anomalous result that two of the
three checks developed Sporotrichum, while inoculated pots
were free from it.

We may conclude from these experiments that Sporotrichum
was pretty generally prevalent throughout the state, and that
probably in many localities there was no necessity for its arti-
ficial distribution in 1895.

How much this general presence of Sporotrichum was due
to its distribution by the Station in former years it would be
impossible to say.

Experiment 26. Open-box experiment in the laboratory. This
experiment was made under different conditions from the fore-
going, and is not given in the series in the order of its date.
Wooden boxes were used instead of flower-pots. The boxes
were left uncovered, so as to give conditions more nearly like
those in the open field. The bugs were kept from escaping
from boxes by means of a heavy chalk-line drawn inside the
box on the sides. Box 2 was very shallow, and the bugs were
kept in it by means of a tar-line on the soil of the outer edge.
The bugs for the boxes were taken from a field which had been
artificially infected in 1894 and 1895. We wanted among other

a

Fifth Annual Report. 25

things to learn, if possible, whether the field was thoroughly
inoculated. In answer to this question we found that the lib-
eral addition of Sporotrichum by different methods to the bugs
thus isolated in the boxes did not apparently increase their
mortality. Sporotrichum was very destructive, as well as Em-
pusa, which was not added. by us, but the bugs apparently did
not die of Sporotrichum faster in the boxes inoculated than was
the case in the open field.

The inference is reasonable that the field was thoroughly in-
oculated and would not have profited by further treatment.
Empusa, however, flourished as well in the boxes as in the
most favorable situations in the open field, and this may ac-
count for the fact that the bugs were nearly all dead in the
boxes at the expiration of 20 days, while in the field they were
still numerous.

June 15. Open box No. 1 was started. The bottom of the
box was covered with garden soil to a depth of from one to
three inches, and the sides, which were eight inches high, were
thoroughly chalked down to the soil. Four pots of young field
corn were arranged along the middle of the box, and after the
soil had been well dampened, the bugs, taken directly from a
field, were introduced. There was almost a pint of them,
mostly pupe. A few fungus-covered bugs were scattered near
and on the pots. The box was placed near a west window so
as to get three to four hours’ sunlight every day. This was
done with the intention of making the conditions in the box as
nearly as possible like those of an ordinary field.

June 16. Bugs thick on stalks of corn, causing it to wilt.
Corn renewed ; very few bugs escaping over the chalk.

June 17. Quite a number of dead bugs (white) were noticed.
They were scattered in patches on the surface of the soil. This
appearance of Sporotrichum so soon after the starting of the
box was doubtless due to the presence of the disease in the field
from which the bugs for stocking the box had been taken —
this field having been infected last year and also this spring.

June 18. Slight increase in number of dead bugs. Corn
repotted.

June 19. No perceptible increase of dead bugs. Results in
the box are much like those in the corn-field from which the

\

26 Contagious Diseases of the Chinch-bug.

bugs were taken, there having been many dead bugs there on
the 17th, but few since.

June 20. Sprayed the bugs with sprouted spore-solution.

June 21. Bugs seem to be dying slowly, and white ones are
gradually getting thicker on the surface of the soil.

June 22. Sprayed with sprouted spores. Open box No. 2
started. This might more properly be called a table, as the
sides were only an inch high—just enough to hold in the dirt.
This box was about 10 feet long by 3 feet wide, and was divided
into three sections. The bugs, taken as before from the corn-
field, were kept in the box and prevented from crossing the lines |
dividing the three sections by means of a line of tar. This line
was about one inch wide, and was renewed daily. Two pots of
corn were placed in each section. Section A was sprayed with
ordinary artificial culture. Section B was infected with dis-
eased bugs. Section C was sprayed with sprouted spores. This
box was also placed so as to be in the sunlight a few hours each
afternoon.

June 23. Nothing new in box 1. No results in box 2.

June 24. Bugs in box 1 had for several days been gathering
in large numbers in the corners of the box, as well as on the
corn. Many of them were moulting, and newly-winged bugs
could be seen. A few bugs were dying every day. Box 2, no
results. Fresh corn putin. Tar-line renewed.

June 25. Box 1. The soil was thickly speckled with white
bugs, but they were not perceptibly more numerous than the
day before. Box 2. Noresults yet. The bugs in box 1 have
almost all reached the adult stage. /

June 26. No increase of Sporotrichum in box 1, but large
numbers of bugs covered with Empusa aphidis. Ground coy-
ered in one corner of box, and many bugs stuck on the pots.
Very sudden and remarkable growth. Box 2 had a few Sporo-
trichum bugs in each section.

June 27. A slight increase of Empusa in box 1; no change
in Sporotrichum. Box 2 showed no increase of Sporotrichum.
Some of the winged bugs escaped over the tar. One Empusa
bug was found on a pot in C in the morning, and several more
in the afternoon. No Empusa had yet been noticed in the
closed boxes. It developed perceptibly in box 1 during the
day.

i

Fifth Annual Report. OT

June 28. Box 1 had a new growth of Empusa; dead bugs
thick on the ground in places, and sticking to the sides of
flower-pots. . The Sporotrichum had not perceptibly increased.
The old growth of Empusa had largely disappeared, having
dried up. Box 2. Slight increase of Empusa and Sporo-
trichum. Not over a dozen dead bugs in each section. Em-
pusa was found for the first time in the closed infection boxes.
One box had an abundant growth. The box was not unusu-
ally damp, and no reason for the appearance of Empusa there
rather than elsewhere could be given. Open box No. 1 was
rather dry when Empusa first appeared, but it was thoroughly
dampened the same day and the growth of the fungus was not
at all retarded.

June 29. Box 1. No very noticeable change in amount of
either fungus. Box 2. Slight increase of Sporotrichum. Per-
haps a little more in B than elsewhere. This section was
largely shaded by a division wall between the windows.

June 50. Slight increase in both boxes.

July 1. Same as yesterday.

July 2. No change except that Empusa does not seem to in-
crease in box 1.

July 5. Bugs almost all dead in box 1.

In box 2. There seems to be no difference in the different
divisions: Empusa and Sporotrichum are the same in both.

V.—FIELD EXPERIMENTS.

Our observations and experiments in the field were not at
variance with those in the laboratory. Whenever conditions
were favorable we found Sporotrichum and often Empusa.
The infection seemed to be generally distributed and only
awaited favorable meteorological conditions for its manifesta-
tion.

All fields did not give the same results because of different
soils, drainage, etc. But the results were alike in that we were
unable to get satisfactory evidence that the artificial distribu-
tion of the infection was of much assistance. We conclude from
this that Sporotrichum survived in Kansas through the winter
of 1894—’95, and was present over large areas in sufficient quan-

28 Contagious Diseases of the Chinch-bug.

tities to destroy all bugs susceptible to the infection as soon as
the weather became favorable for the growth of the fungus.

We will here detail two of the field experiments which will
be fairly representative of all.

The first experiment, which is also the first of the season,
shows an exception to the rule above stated in that the artificial
infection appeared to give favorable results at first. Later,
however, results could not be determined with certainty.

1.— FIELD EXPERIMENT No. 1.

On March 10 chinch-bugs were found hibernating in great
numbers under stones on Mr. Marshall’s farm near Willow
Springs. Sporotrichum had been distributed on this farm in
1894. On March 23 half a pint of live bugs were gathered from
under the stones on this farm, and at the same time spores of
Sporotrichum from artificial cultures on squash and turnip were
dusted under the stones dry, and also sprayed in water. On
March 30 the bugs were reported to be dying under the stones
where the infection had been put.

On April 2 Mr. Marcy visited the farm, and found from five to
10 bugs dead with Sporotrichum under each stone where the in-
fection had been put, but he was unable to find any Sporo-
trichum where the infection had not been distributed.

On April 14 Mr. Marcy again visited this farm, and the bugs
were very much diminished. Sporotrichum had increased, but
not in sufficient amount to account for the diminution of bugs
observed, and it is concluded that the bugs had scattered.

On June 25 Mr. Marcy again visited this field. Before this
date Mr. Marshall had infected the field with Sporotrichum-
covered bugs, and the wheat had been cut and the bugs had
passed to adjoining timothy and corn fields. On the borders
of the wheat-field, where the ground was shaded by a rank
growth of weeds, bugs dead and covered with Sporotrichum
were found in great abundance; but still the bugs were quite
numerous in the timothy and corn fields and were doing con-
siderable damage.

On another farm worked by Mr. Marshall, about three-fourths
of a mile distant, artificial cultures of Sporotrichum had been
applied with a sprayer, and Sporotrichum was found abundant ;
however, four or five acres of corn had been destroyed at this date.

Le
. je J

Fifth Annual Report. 29

Farms in the neighborhood where infection had not been used
were in essentially the same condition. Sporotrichum was
plentiful, but the corn was considerably damaged.

2.—FIELD EXPERIMENT No. 2.

Near the University campus was a field of wheat, which we
will call A, with a corn-field adjoining it on the south, which
we will call B. No other grain-fields were adjacent to it. On
the rocky hillsides bordering the wheat-field on the north and
east chinch-bugs were found early in the spring hibernating
under the loose surface stones. Early in April the bugs were.
found in large numbers all over the wheat-field.

Sporotrichum was distributed in the wheat-field, and later in
the corn-field, by various methods, as is shown by the following
notes :

April 11. Sprayed with the squash culture of Sporotrichum
on the north side of field A. The bugs were thick and the
ground was dry.

April 13. Sprayed the same field A, more thoroughly than
on the llth. Sprayed all around it and through the middle.
Sprayed with the sprouted Sporotrichum from artificial culture
in the field B, around it, and some distance in toward the cen-
ter, on the north side. Bugs were as thick as in A; more than
a dozen could be found around a single blade of wheat.

April 16. Could find no Sporotrichum bugs either in A or B.

April 20. No Sporotrichum bugs; live ones were very thick
on the lower sides of (south side) A and B.

April 25. No Sporotrichum bugs found.

April 27. Sprayed with sprouted Sporotrichum from arti-
ficial cultures on the south side of field B. Could not find any
Sporotrichum bugs.

May 1. No Sporotrichum could be found; soil very dry.

May 2. Rain fell late in the afternoon.

May 4. Bugs to all appearances were healthy. Could find
no Sporotrichum. Sprayed field A. Scattered Sporotrichum
bugs in B; had about one gallon of earth from infection-box
containing bugs covered with Sporotrichum, and this was scat-
tered on the south side of the field. The ground was moist and
in good condition. It was as we like to have it in our infec-
tion-boxes.

30 Contagious Diseases of the Chinch-bug.

May 5. Another rain.

May 6. No Sporotrichum bugs found ; soil moist.

May 9. Found a few Sporotrichum bugs in A and B, but it
was only after diligent search. The ground was quite dry. It
dried up fast, owing to the excessive heat which we had had
for a few days.

May.11. More Sporotrichum bugs in the field.

May 13. Field very dry.

May 15. On the night of the 14th a half inch of rain fell.

May 16. Slight showers of rain last night; misty to-day.
Vast numbers of little red bugs (larvee) found in field. Sporo-
trichum a little more abundant, but not at all plentiful.
Sprayed in a small patch in A, and scattered Sporotrichum
bugs in a small patch in B. Bugs were taken from the field
and put into a flower-pot, which was kept in good condition for
the growth of Sporotrichum.

May 20. Visited both fields after the rain of the 19th and the
morning rain of the 20th. Found only a few Sporotrichum
bugs. The ground was moist and warm. Bugs taken from
field and transferred to pot in the laboratory on May 16 are
dying of Sporotrichum.

May 23. Sprayed field A in a little ravine where the wheat
was large and the bugs thick. Used two jars of the artificial
culture ; also scattered Sporotrichum bugs in field B. Only a
few Sporotrichum bugs could be found. Temperature cool. In
the patches that were infected May 16 can see no results.

May 25. Sprayed in asmall plot in field A with spouted
Sporotrichum from artificial cultures. Only a very few Sporo-
trichum bugs could be found. Bugs in pot taken from field May
16 dead and covered with Sporotrichum.

May 28. ‘To-day and yesterday a drying hot wind prevailed.
(Temperature 90°; wind from the south.)

May 29. Very hot and dry. There seems to be no evidence
that Sporotrichum is spreading.

May 30. Heavy rain last night, and to-day it is misting.

June 1. A few Sporotrichum bugs could be found.

June 5. A large majority of the old bugs can be found coy-
ered with Sporotrichum in the field B, in the southwest part,
where the soil is heavy and the wheat large. A few of the
little larvee could be found covered over with the fungus.

Fifth Annual Report. 31

Bugs moving into the corn in great numbers. The corn-field
was now marked off into four plots. Plot 1 was not inocu-
lated artificially, and served as a check. Plot 2 was sprayed
with Sporotrichum spores from artificial cultures. Plot 3 was
infected by scattering bugs covered with Sporotrichum from the
infection-boxes. Plot 4 was sprayed with sprouted spores of
Sporotrichum from artificial cultures. At this date the wheat
had been cut, and the bugs had advanced in the corn all the
way from 36 rows in plot 1 to about 40 rows in plot 4. Infec-
tion was now distributed as above indicated in rows 4, 6, 15
and 20 in all the plots. .

June 8. Sprayed in No. 2 rows 8, 16,24. Sprayed sprouted
spores in No. 4 in rows 8, 16, 24. Scattered Sporotrichum
bugs in rows 16 and 24 in No. 3. Bugs are advancing. Soil
quite dry.

June 9. At 3 o’clock began to rain.

June 10. Rained all night. About three inches of rain fell.

June 11. Rain did not seem to diminish the bugs. Could
find a little Sporotrichum in all parts of the field.

June 12. Field very moist; muddy in places. Bugs on the
stalks very thick; could find Sporotrichum around all stalks in
plots 1, 2, 3, and 4, as far as the bugs had advanced. A few
full-fledged bugs found. Sprayed in rows 30, 32, 34, and 36,
in plot2. Scattered Sporotrichum in No. 3, in rows 25 and 30.
Sprayed sprouted spores in No. 4, in rows 30, 52, 54, and 36.

June 13. A light shower last night; ground very moist and
warm. Sporotrichum quite abundant, but the bugs are still
doing great damage. More of the mature bugs noticed. Bugs
moulting.

June 14. Sporotrichum abundant. Moist and warm.

June 15. Rainedlast night. Very warm. bugs still moult-
ing, but not in large bunches as has been noticed in other fields.

June 17. Showers yesterday. Warm. Many Sporotrichum
bugs, but ae many still alive; the ground around each stalk
in rows 2, 3,4, etc., is thickly spotted with Sporotrichum bugs.

June 18. Very ee rain last night, washed most of the
Sporotrichum bugs away; could only find them around the
roots of the corn. At first sight, one would think that the live
bugs had been washed away by the rains, but a closer examina-
tion showed that they were hanging to the leaves of the corn,

32 Contagious Diseases of the Chinch-bug.

weeds, etc. After diligent search, only a few bugs could be
found covered up in the mud. !

June 19. Bugs in corn, and very active. Only a few Sporo-
trichum bugs could be found. These were most abundant in
plot 4 where the weeds were large and made the soil moist and
shady. Bugs still moulting.

June 20. Only alittle more Sporotrichum than yesterday ;
Bugs beginning to scatter.

June 21. Bugs moulting and scattering. Very hot.

June 22. Could see no change from yesterday. Very hot.

June 24. Bugs still scattering all through the field.

June 26. A few bugs flying, but not many. Hot.

June 28. Cooler.

June 29. Rained all day.

June 30. Misty and rainy.

July 1. Large number of Sporotrichum bugs could be found
in the field. Ground moist but not muddy. Bugs have scat-
tered all over the fleld.

July 8. Sporotrichum very abundant.

July 5. Heavy rain on the 4th.

July 8. Plenty of Sporotrichum and some Empusa could be
found in all parts of the field, especially where it was weedy.

July 24. Bugs still in the corn, some little red larve.
Sporotrichum quite abundant. After the wheat had been cut
in fields A and B, the stubble was turned under and millet was
sown in the south half of A and corn was planted in the north
half. Corn was also planted in B. After these had made a
fair growth the bugs invaded them from field C. On the Ist of
August the bugs, including many red larve, were plentiful ,in
these fields. Sporotrichum was also abundant.

August 5. With a large sprayer, 45 gallons of Sporotrichum
spores in water, from artificial cultures, were sprayed over the
young corn of field A.

August 19. Apparently the beginning of an Empusa epi-
demic in millet of field A. August 17 and 18 were warm,
sunny days, but some very wet weather had preceded. Some
Empusa bugs were found in this field August 16. Some red
bugs were placed in a test tube on the afternoon of August 19.
August 20, one bug found covered with Empusa. No signs of

Fifth Annual Report. 33

Empusa noticed when bugs were put in, but this bug on August

20 had a vigorous growth, and spores were being abjected.
August 22. To-day found the first full-fledged bugs of the

second brood. Empusa is spreading quite rapidly. There is

- not as much Sporotrichum as in the beginning of the month.

August 23. Several pale-winged bugs just moulted seen in
millet, but proportionally very few, perhaps one to several
thousands.

August 24. Wet morning after heavy rain previous evening.
Many Empusa bugs. Moulting still going on. Bugs in millet
more advanced in age than those in corn.

August 28. Empusa spreading, and it is diminishing the
bugs in millet quite rapidly.

September 5. Empusa doing good work.

September 9. Empusa abundant in corn-field A. Could find
but two Sporotrichum bugs in any of the fields.

September 138. About 8.45 a.m. Much Empusa in millet-
field. Comparatively littleincorn. Groundvery moist. Rained

hard on the 8th; no rain since to amount to anything.

September 14. Bugs comparatively few in millet-field, not so
much fresh Empusa as on other mornings recently. Number
of bugs in corn-field not much diminished. Great majority of
corn-field bugs are black, but some are moulting for the last
time. Bugs in corn mostly in axils of leaves. Two Sporo-
trichum bugs were found in millet. Millet is drying up in
places but still green in lower part of field. Corn green. Warm
morning. The 15th was hot and dry.

September 16. Bugs very few in millet, and great majority
there winged. Empusa comparatively abundant and much of
it fresh-looking. In corn bugs very much fewer than earlier in
the season; some stalks with very many on them, but large
number of stalks which had numerous red bugs have very few
now. Little disease of any kind in corn. Sporotrichum in
millet more abundant than during any recent time past. Light
shower on morning of 16th, but 15th and practically all of 16th
hot with clear skies. Some bugs flying.

September 17. Morning warm, clear, with southwest wind.
In millet no more fresh Empusa than on morning of 16th.
Millet getting old, and many bugs in upper part of stalks. In
corn bugs moulting for last time. More abundant on certain

—3

34 sited: Diseases of the Chinch-bug.

fallen stalks. Ltete disease except in a few low places where
ground was still moist; there Empusa was found.

September 23. Urea cool, no wind; first frost of season.
Slight rain on 22d, which was first rain for several days. Bugs
in corn seem to continue to decrease, mostly winged: One or
two Empusa bugs seen; but very little disease. Bugs still
moulting. In the millet-field, bugs hardly found except in one
spot, where they were still abundant, mostly winged. Empusa
plentiful there, but most of it old-looking.

September 27. Rain on the evening of the 18th. Bugs
seemed to be fewer than ever, all or practically all winged.
Very little disease seen, no fresh Empusa. Nights have been
cool, and the ground is moist; corn being cut up. The few
bugs found were under leaves; that is, between leaves and
stalks of corn.

September 30. Bugs very few in corn-field, and plentiful
only in the one small patch in millet-field. Mostly mature ;
but a few black pupze seen. In corn, they were found for most
part between leaf-sheath and stalk, in still green stalks, in
much the same situation in which they were found at this time
last year.

.Plate VI shows the injury to the corn in field C due to chinch-
bugs: The wheat-stacks are standing in the wheat-field from
which the bugs came.

VI.—FIELD OBSERVATIONS.

Taken by Mr. M. A. BARBER, during a journey made in the month of July, 1895, through the
southeastern portion of Kansas.

The following is a summary of the results obtained during a
trip in July through a region in the southeastern part of this ©
state. The route was as follows: From Lawrence to Burling-
ton, through the counties of Douglas, Franklin and Coffey ;
from Burlington to Fort Scott, through Anderson, Allen and
Bourbon counties; and from Fort Scott to Lawrence, through
Linn, Miami, Franklin and Douglas counties. The journey
occupied about 14 days, from July 4 to July 17, inclusive, and
was made on horseback, so that there was opportunity for ex-
amining any field along the route. In general the fields ex-
amined were those in which the crop consisted of small grain
or crops near fields of small grain, although other fields were

ah

Fifth Annual Report. 35

examined to determine the relative number of bugs in various
kinds of crops.

Most of the fields along the route in which there was evi-
dence that bugs were present, or had been present, were exam-
ined, or if there were several such fields in any vicinity under
similar conditions, one or more of them were examined to serve
as types for the remainder. Besides, a number of fields were
examined in which there were no signs of bugs. The quality
of the soil, humidity of the soil, condition of crop, injury to
crop by chinch-bugs, position of field in relation to other fields,
hedges, ditches, etc., the relative number of living chinch-bugs,
and the stages of development in which they were, and the
presence and relative abundance of Sporotrichum and Empusa,
were all noticed. Whenever possible, it was determined whether
Sporotrichum had been introduced into the field examined dur-
ing the season of 1895, or at any other time, and whether it had
ever been introduced into a neighborhood or not. Also, the
meteorological conditions prevailing during the time of the
journey were noted, and the conditions which had prevailed in
the different localities for some time previous were determined
in many cases. .

There had been flights of chinch-bugs in Douglas county at
different times, late in June and early in July, before this trip
was begun; and there were evidences in some cases that there
had been a scattering of the bugs in localities along the route
of the journey. Also, it is very probable that many bugs
covered with Sporotrichum and Empusa had been washed away
by heavy rains or made to disappear by other causes. This
condition necessarily affected the relative abundance of living

chinch-bugs in different localities at the time of examination,

and the relative amount of bugs covered with Sporotrichum and

Empusa as compared with the living.

There were in all about 109 examinations made, a single ex-
amination sometimes including several adjacent fields. In
these examinations chinch-bugs living or dead were found in
92 cases. In these 92 cases Sporotrichum was found in 80
cases and abundantly found in 25 of the 80. Empusa was
found in 58 cases in the 92, and abundantly in 15 eases.
Twelve cases were noticed in which bugs covered with Empusa
nearly equalled or exceeded those with Sporotrichum. In 36

36 Contagious Diseases of the Chinch-bug.

cases there was apparent injury done to crops, varying in
amount from a very narrow strip along the edge of a field to 24
acres. Where several fields immediately adjoined one field
from which the bugs had migrated, they are counted as one
ease. In 14 cases it was ascertained that Sporotrichum had
been artificially introduced into the place examined in 1895;
but in the great majority of cases where information:was ob-
tained on this point, artificial infection had not been used in
1895. However, there were very few localities visited where
artificial infection had not been used at some time, either on
the farms examined or in the neighborhood.

Of the fields visited there were 35 in which bugs were found
to be abundant, or in considerable numbers at least. In some
cases two or three of these fields adjoined one another, but, in
general, they represent different localities. Of these 35 fields,
Sporotrichum was found in 34 cases—abundantly in 19 of the
34. Empusa was found in 24 of the 35, and abundantly in 9.
Artificial infection with Sporotrichum was used in 1895 in 7 of
the cases in which information was obtained ; in the majority
of cases infection had not been employed in 1895, so far as
known. In 20 of the 35 fields there was a considerable injury
to the crop. The crops were approximately as follows:

Commmear wiheat-nela ii rary Sawn g ie Wien Oe ALG ae iad ae RL ARS Seo 13 fields.
Conn near 7Ve-Telds fyi5- 3c) Ik as cE Ben ROU ore apa ee ee AO
Gorn near Oat HELIS) As ey ONO TI A IN UAV UNE aN PLEAS Gs aN st
Corn: nob near small rain. ane aoe ys Neel MCENROE SO pep Ov
CO ais eRe en NI Pre Red ANNE Ne RAN PORE RCY a 2c ne ga ACE Dh oye
AL a raat a GEN VRE BERN Uc IP RIAN DI: ARDS Waid fh aL hm Oe Se AACN Syst
MVE iia iia ea UC Rai la wt Bh Ws eel te DS AM Uae oS LP the

In 22 fields the soil was upland; in 10 river or creek bottom.
In most of the fields the surface of the soil was moist, and in
all, practically, the ground was moist just beneath the surface.

The 35 fields in which living bugs were abundant gives per-
haps a fairer notion of the distribution of Sporotrichum and
Kmpusa than the whole number of cases in which bugs were
present, because, where bugs were few, Sporotrichum, if pres-
ent, was as a rule correspondingly scarce, and the chances of
overlooking it in a field where there is very little of it are much
greater than in fields where both living and diseased bugs are
relatively abundant. The weather, as noted by myself, for the
different days and the localities in which these observations
were taken, are as follows:

Fifth Annual Report. 37

July 4. Douglas county and northern part of Franklin.
Hot to middle of afternoon; showers in late afternoon, and a
very heavy rain at night.

July 5. Franklin county and northeastern part of Coffey.
Cool forenoon, warm and sunny in afternoon.

July 6. Coffey county. Warm all day.

July 7. Coffey county. Warm, cloudy in afternoon.

July 8. Coffey county. Warm all day, with a slight
sprinkle. ’

July 9. Coffey county and southern Anderson. Warm and
sunny.

July 10. Southern Anderson and northeastern Allen county.
Cool, cloudy, and rainy.

July 11. Bourbon county. Cool, cloudy with rain and mist.

July 12. Bourbon county. Cloudy and warm; fields begin-
ning to dry.

July 18. Linn county. Cloudy all day. Very little rain in
afternoon. Surface of soil getting dry in places.

July 14. Northern Linn. Sunny all day, with strong wind.
Ground drying rapidly.

July 15. Linn county and southwestern Miami. Very hot
and clear; no wind.

July 16. Western part of Miami, and northeastern part of
Franklin, and southeastern part of Douglas. Clear; very hot,
with strong south wind.

July 17. Douglas county. Clear and warm.

From information obtained from farmers and others along the
route, and from evidences afforded by the soil and the condition
of vegetation, it is concluded that there had been sufficient rains
to keep the soil moist and. the crops growing well during the
latter part of June and the early part of July. In Bourbon
county the weather had been wet for some time previous to the
time of my visit. In the eastern part of the county it was said
to have been too wet for plowing for three or four weeks. In
the northern part of the county wheat was found germinating in
the spikes on the outer portions of shocks, above the ground, indi-
cating that very moist conditions had prevailed for some time.
The rain of July 4, and the wet cloudy period of July 10 to 13,
inclusive, were general over the portion of the state visited.

It is not possible to make many broad generalizations from

38 Contagious Diseases of the Chinch-bug.

the results obtained during this journey, for although consider-
able territory was examined, the fields for the most part were
seen but once during the season, and their previous and subse-
quent history could not be definitely known. It is safe to
assume, however, from the results of these observations, that
Sporotrichum was very generally distributed over the territory
examined, and this was not the result of artificial dissemination
of the disease in 1895. It may, however, have been the result
of artificial introduction of the disease in preceding years. Fur-
ther, Empusa was found very generally distributed where
conditions favored its development. In many of the fields
examined the bugs seemed to be dying of Empusa far more
rapidly than from Sporotrichum. In these places the hu-
midity was great, and in some instances there was evidence
that there had been a relatively greater epidemic of Sporotrichum
at some previous time. There seemed to be no necessary rela-
tion between the prevalence of epidemics and the nature of the
soil, except in so far as the character of the soil affected the
humidity of the surroundings.

Apparently, continued cloudy weather favored epidemics, for
there was evidence of a relatively greater diminution in the
number of the bugs after the wet, cloudy period which occurred
during the journey, and also in those regions where rains had
been most abundant during some weeks preceding the obser-
vations. |

In Bourbon county, for instance, where the weather had been
moist for some time, there was evidence of a greater reduction
in the number of the bugs than in the part of Douglas county
examined during the first day of the journey. It is not easy to
give a general estimate of the damage to crops, for in many
cases the crops had been harvested and in others it was not
always possible to determine whether the damage observed was
wholly due to chinch-bugs or to other agencies as well. Besides
the condition of the crop when the invasion of insects occurred
and for some time subsequently could not be accurately de-
termined in all cases. Living chinch-bugs were found in dif-
ferent stages of development in most of the cases examined, but
black pupz and mature insects were most abundant.

Fifth Annual Report. 39

VII.—FIELD OBSERVATIONS.

Taken by Mr. W. W. Brown in Coffey county during June, 1895.

The field which I observed was one belonging to Mr. Throck-
morton, living about two miles north of Burlington. Mr.
Throckmorton got the infection from me, and infected the field
himself. The work of infection was commenced early in May.
In about two weeks the bugs began dying. On the 3d of June
I visited the field and found many old bugs dead. I went to
different parts of the field and found bugs dead everywhere,
but more numerous in the low places of the field. The field is
rather low ground. Dry weather had been prevalent, but on
the 30th of May there had been arain. I found many young
red bugs on the ground and a little way up the stalks of the
wheat. I found some young bugs dead, but very few.

June 4. I again visited the field for the purpose of picking
up fungus-covered bugs. I picked up 150 boxes for distribu-
tion among the farmers. I found the bugs as they were yester-
day except that they were moving over the ground more. I
thought there were more young bugs dead, but perhaps in pick-
ing I could observe more closely and thus could see the smaller
fungus more readily.

June 8. I went with Marshall Barber to the field. The
weather was dryer than when I was there on the 4th, no rain
having fallen since the 3d. We visited many parts of the field
and found dead bugs, both old and young, in every part. Mr.
Throckmorton was still spreading the infection, picking it up
in one part and putting it where the bugs were advancing into
an adjoining oat-field. There were no changes observable in the
condition of the bugs except they had grown blacker, and there
were more young bugs dead. We made a careful estimate of
the proportion of young and old bugs dead, and we found it to
be about seven young bugs to one old. We also found the in-
fection in a field a half mile distant in which it had not been
put this year, but was put in 1894.

June 13. I went to the field and picked up 100 boxes of
bugs—fungus covered. A heavy rain had fallen on the 11th,
and I could not find many fungus-covered old bugs, but there
were very many young bugs covered with fungus, too small to
pick up for the boxes. We found the bugs gathering and be-

40 Contagious Diseases of the Chinch-bug.

ginning to moult, and some were already moulted. Many had
gone to an adjoining corn-field and had killed some of the stalks.
They had been yery numerous in the wheat, but had not yet
proceeded far into the corn. They were not working so fast in
this field as in an adjoining field not infected.

June 17. Bugs nearly all gone from wheat-field. Visited
corn-field, and found afew dead bugs atthe hills. Bugs piling up,
and a good many winged bugs to befound. The bugs were going
from the corn to an oat-field on the east. They were all, or
nearly all, black, and were well grown and winged. Bugs on
east side of oats came out of a wheat-field, and along this side
infection had been placed. The dead bugs here covered the
ground, numbering about 30 to the square inch. One thing
was noticeable: the bugs were mostly red, indicafing, we
thought, that they were still coming from the wheat-field as
they hatched. There seemed to be three kinds of fungi—the
sporo, another of a watery color, and another of a silken or
webby appearance. The oat-field was beside a corn-field, and
the bugs came from the wheat-field into the oats and corn
alike. In the corn they were dying very slowly, only a few at
each hill; but in the oats, 10 feet distant, they were as above
described. Infection had been placed in corn and oats alike.

June 20. Visited the oat-field and picked up 134 boxes for
distribution. The dead bugs were about twice as numerous as
they were three days ago. The living had decreased to about
one-tenth of what they were. I cannot say what became of
them. Probably, being older and stronger, more of them than
of the young bugs had burrowed into the ground when dying.
They had moved a little farther into the oats, but not sufficient,
I think, to account for the great decrease. The bugs that were
there were not eating, but slowly crawling over the ground or
piling up to moult. Young bugs were still coming from the
wheat-field. The bugs had not gone over 20 yards into the
oats, and had hurt the oats only about eight feet. They were
not dying, or at least very slowly, in the corn, only a few being
dead at each hill. The ground was dryer than on the 17th.
The weather up to this time had been good growing weather,
but at no time during the entire spring could it be considered.
wet. JI have come to the conclusion that the infection will
work readily in the ordinary season in oats and wheat, due to

Fifth Annual Report. Ay

the moisture in the bottom, but not in small corn; not enough
to be practical. What might be done in wetter weather, I am
not able to say. The water-colored greenish fungus mentioned
in report of 17th is more numerous to-day, and more vigorous,
not, however, in very great quantity.

From this time on my observations were not confined to this
field. About the Ist of July a little rain fell, and reports came
in that the bugs were dying in the corn-fields very rapidly. On
the 4th of July a heavy rain fell, and wet weather followed.
From the 1st to the 15th the bugs were killed by the fungus on
nearly every field where they were so far as I could learn. [I
concluded that there was another cause at work to render the
fungus more effective than that of rainy weather, from the fact
that from the Ist to the 4th there was but little more moisture
than during the days immediately preceding, and not so much
as during the early part of June. Yet reports came in that the
bugs were dying rapidly in the corn-fields before the rains of
the 4th and the days following.

VITI.— CONSIDERATION REGARDING STATUS OF SPORO-
TRICHUM.

We have said that the conditions upon which the spread of
Sporotrichum among chinch-bugs depends are complex and not
entirely understood. We will here offer certain considerations
regarding the status of Sporotrichum which may be suggestive
to those interested in the work of the Station of the difficulty
of reaching positive conclusions without data ranging over a
long series of years and embracing a wide range of meteoro-
logical conditions.

A.—That Sporotrichum generally throughout the state survived
the winter of 1894-95 is indicated by the following:

1. It was found in 1895, early in the spring and at different
times during the year, in many fields where no Sporotrichum
had been artificially introduced in 1895. It was present in a
great majority of fields examined where bugs were abundant,
and was found in different parts of the state.

2. Chinch-bugs sent to this Station from many different lo-

42 Contagious Diseases of the Chinch-bug.

calities were, in almost all cases, already infected with Sporo-
trichum.

3. Sporotrichum was found in healthy condition out of doors

in January, 1895, and again about April 1, 1895.

B.—That Sporotrichum survives all winter conditions which

chinch-bugs withstand, and that artificial infection ts consequently
in most cases not necessary is indicated by the following:

1. Its survival of the winter of 1894-95.

2. Probability that no conditions exist which would allow
bugs to hibernate safely, and at the same time destroy wholly

the spores of Sporotrichum, which it would seem have, on |

account of their small size and great abundance, as good a
chance of finding effectual shelter as the bugs themselves.

3. General epidemics of Sporotrichum have been noted in
other years before artificial spread of this disease was employed.

4. The wide-spread occurrence in 1895 of a species of Em-
pusa on chinch-bugs; a species which, so far as known, has
not been artificially disseminated since the years 1892 and 1893,
and then not widely.

C.—The validity of the arguments under B, namely, that Sporo-
trichum survives all winter conditions which chinch-bugs can with-
stand, depends, toa great extent at least, on the following assumptions:

1. That the winter conditions of 1894—’95 are similar to those
of other winters, so far as the possibility of their effectually
destroying Sporotrichum is concerned.

2. That Sporotrichum will be present with chinch-bugs in
their winter quarters, and be exposed to practically similar con-
ditions.

3. That the epidemics in question were present so generally
that the possibility that the disease may have spread from
certain specially favored localities is excluded.

4. That the species of Empusa referred to bears the same re-
lation to destroying agencies that Sporotrichum does, so far as
the continuance of the disease from year to year is concerned.

D.— Proposition B, namely, that Sporotrichum survives all winter
conditions which the chinch-bug can withstand is opposed by the
following : i

sm Chinch-bugs from different localities have been kept, with-

out the addition of infection, in moist jars or boxes and have re-

ape

Fifth Annual Report. 43

mained free from Sporotrichum ; while bugs infected and kept
in similar jars have been found dead with Sporotrichum on
them. This has been done at different times and in different
states.

2. Localities have been reported in which bugs were abun-
dant, but no Sporotrichum could be found.

E.— The validity of the arguments ae D depend on the follow-
ing assumptions :

1. That the chinch-bugsin the check-jars were, in all respects,
under conditions favoring the appearance of the fungus if it had

been present.

2. That conditions favoring the development of Sporotrichum
prevailed in the localities mentioned at the time when the
fungus was sought; so that if it had been present, it would
have become visible. Further that the search was complete
enough to have discovered any fungus-covered bugs if they had
been present.

Nore.— Different lots of chinch-bugs kept in jars under conditions, so far as
known, similar for all, have shown very different results as regards the develop-
ment of Sporotrichum i in different jars.

F.—Further evidence on the above question may be sons et from
the following sources :

1. Localities may be found in which the chinch-bugs prevail
that are so situated that it is not possible for Sporotrichum to
have been artificially introduced.

2. It may be determined whether Sporotrichum continues to
survive a long series of winters, as it apparently has done in
the years 1894-’95.

We suggest the following final considerations :
A.

Sporotrichum was well distributed in this state at the begin
ning of the season of 1895, so that the question of whether or
not infection was present does not enter into the explanation of
the varying results observed in fields where bugs were abun-
dant.

B.

It is very "probable that where Sporotrichum and Empusa

are present serious epidemics may occur if certain conditions

44 Contagious Diseases of the Chinch-bug.

are present. These conditions we do not know exactly, but it
is probable that the following tend to promote epidemics :
1. Humidity, resulting —

(a) From sufficient rain or cloudy weather.
(6) From conditions of soil or surrounding vegetation which tend to retain
moisture.

2. Increased susceptibility of insects to diseases. This pos-
sibly may come about —

(a) From exhaustion after breeding, laying of eggs, etc., and the weakening
of the insect at old age.

(6) From the weakening effect of unfavorable meteorological conditions.

(c) From the effect of other diseases or pathological conditions of some kind.

C.

1. It is more than probable that Sporotrichum is always
present to a greater or less extent in any locality, and that the
amount of it depends primarily upon the number of chinch-bugs
and the condition of the weather.

2. Since dry weather favors the multiplication of the chinch-
bug and is detrimental to the development of Sporotrichum, the
assumption seems reasonable that a series of dry years would
result in an increase of chinch-bugs without a corresponding
increase of Sporotrichum.

3. In such an event we would conclude that the artificial in-
troduction of Sporotrichum would result in the destruction of
more bugs than would naturally occur.

4. Finally, with these considerations, we suggest that it is
best for the farmer to see that the diseases are present in his
fields, so that if favorable conditions arise, an epidemic may re-
sult; but it is not wise to put entire dependence on infectious
diseases, for it is uncertain whether these conditions may arise,
or, if they do, whether they may be in time to materially aid
the crops.

IX.— THE BARRIER METHOD.

The habit of chinch-bugs of leaving the small-grain fields in
a body about harvest-time, and migrating to the corn-fields,
where they literally blacken the first few rows, is too well known
by farmers to dwell upon. The bugs go on foot in’these migra-
tions, and the winged ones are seldom known to fly. At such
times it is possible to trap and destroy the bugs almost utterly.

~~ . =a

Fifth Annual Report. 45

Various methods of accomplishing this have been in vogue for
many years.

As soon as it was seen that infectious diseases would probably
not always be efficient in destroying the chinch-bugs in sufficient
numbers to save the crops, our assistant, Mr. Marcy, turned his
attention to coal-tar, petroleum and salt as barriers to keep the
bugs from entering the corn-fields.. The plan found most effect-
ive was that of turning a double furrow with a plow and thus
forming a ridge, and putting the tar, etc., on top of this ridge.
On the side of the ridge next to the small grain, post-holes
were dug broadening toward the bottom, about 100 feet apart. .
The bugs were retarded in their march by the ridge, and being
repelled by the tar, etc., would swarm along the ridge, and in
so doing would crowd each other into the post-holes. In some
cases, when the holes were nearly filled with bugs, dirt was
thrown in and packed down; in others a little petroleum was,

poured. Both methods were effective in killing the bugs. It

was found that where the holes were deep the bugs died with-
out any special effort to destroy them.

After the ridges are thrown by the plow it is best to smooth
and pack down the top and sides somewhat, in order to keep
the tar, etc., from sinking in deeply and to protect the ridge
from too great washing away by rains. This process was neces-
sarily slow and tedious by hand, and to obviate this a drag with
a concave bottom of the form of the ridge was made, and when
weighted with rocks or dirt and drawn by horses over the ridge
it did very effective service, saving a vast amount of time and
doing the work better than could be done by hand. The bot-
tom of the drag was found to scour much better when covered
with sheet zinc.

Coal-tar as it comes from the gas-works, crude petroleum ase=
taken from the oil-well and kerosene oil mixed with salt were used
on the ridges. These substances are offensive to the bugs, and
they seldom attempt to cross them or even to come close enough
to touch them, but on approaching these offensive substances
the bugs turn and run along the ridge in the evident hope of
finding a gap through which they may pass.

Coal-tar is the best of the substances named in that it stands
on the surface better and is not so readily washed away by
rains. However, crude petroleum and kerosene are very effi-

™ Aone ate vary

46 Contagious Diseases of the Chinch-bug.

cient and are more generally available than the coal-tar. The
coal-tar can be easily applied by means of an old teakettle,

sprinkler, or coffee-pot. The stream poured upon the ridge
need not be more than half an inch in diameter, and when of
this size the operator should walk rather rapidly in applying it.
Where coal-tar is not available, crude petroleum or kerosene
oil may be mixed with common coarse salt and a line of this
may be strewn on the ridge with the hand or in any other man-

ner preferred by the operator. All of these substances are ©

cheap enough to be profitably used.

The results of this method of combating chinch-bugs were well
shown by experiments in a wheat-field. The bugs were noticed
early in this wheat, and just before harvest and before the bugs
had migrated to the corn the ridge was thrown up, coal-tar was
applied and the post-holes dug. The bugs which collected and
died in the first few holes were taken out and piled near the
holes in great quantities. Only a few bugs escaped, and no
damage was done the corn.

In another case, the bugs had left the wheat and Hal ad-
vanced about 50 rows in the corn, destroying it utterly as they
advanced. Sporotrichum had been: scattered abundantly in the
field, but although many bugs died of the disease, the injury
to the corn was not materially abated. Then the ridge was

thrown up,, tar was put on, and post-holes dug. The result >

was that the bugs were caught and died in the holes, so that
the corn suffered no further injury. These two instances dem-
onstrate the value of the barrier method described above.
Equally good results were obtained with kerosene oil mixed
with salt. If the ridge is not formed and the offensive sub-
stances are simply spread upon the ground, the bugs, when in
great numbers, crowd each other across the barrier, those in
front being unwillingly carried forward by those behind; or, if
the post-holes are omitted, the bugs are not destroyed, and
manage finally to straggle into the corn-field after the barrier
has become damaged by the weather. °

The barrier method has the advantage of not being dependent
upon a complexity of conditions for its success, and of giving
immediate results. It has the disadvantage of being only ap-
plicable at the very short time when the bugs are migrating
from one field to another. It cannot be used upon bugs already

>
<a e

Fifth Annual Report. ca Os

scattered through the small-grain or corn-fields. But this dis-

advantage is largely done away with if the farmer is provided
with the necessary material, and watches his fields so as to be
able to make the barrier at the critical time. The wisdom of |
using the barrier hardly needs argument. When the farmer
has worked two or three months on his corn-field, he would
hardly grudge two or three days’ labor to save the profits of his
season’s work from being wiped out by chinch-bugs.

Notwithstanding the success reported in former years by a
large percentage of the farmers using the white-fungus infec-
tion, there have been enough failures to teach us not to put
entire dependence in this, but to supplement the infection by a
method that will succeed where the infection fails. The barrier
method just described has succeeded admirably in our experi-
ence. The infection requires time to become established in the
field; but when the bugs are swarming into the corn-fields
there must be no delay, for in a very few days the bugs may
destroy many acres of corn. The place to use the infection is
in the small-grain fields and in the corn-fields if the barrier
has not been used in time, or if bugs fly into the corn later in
the season, as often happens.

A PLAN OF DEFENCE AGAINST THE CHINCH- BUG.

1. Assoon as the season opens in the spring, search for chinch-
bugs at the roots of grasses and small grain, and under sticks,
stones and all sorts of debris that might give shelter to bugs.

2. If bugs are found and Sporotrichum is not present among
them, it should be introduced into the field as soon as possible.
Infection-boxes may be started with bugs taken from the field
as soon as they can be obtained. If Sporotrichum is found
already in the field, it is probable that its artificial introduction
would be unnecessary. The spread of Sporotrichum among
the bugs is not to be anticipated if the weather continues dry.
The fields should be visited frequently, both to watch the prog-

ress of disease and the movement of the bugs.

3. Do not let the bugs enter the corn-fields. As the small
grain ripens the bugs begin to suffer for food, and may migrate
to the corn-fields at any time. Frequently, however, the mi-
gration does not take place until the small grain is harvested.

48 Contagious Diseases of the Chinch-bug.

The barrier should now be raised. It would be well to form
the ridge for the barrier a week or two before it is needed.
(Ridges formed last summer by Mr. Marcy’s drag were in ex-
cellent condition after having withstood the heavy, beating
rains of July and August). Then the tar, kerosene, etc., may
be spread at a moment’s notice and the post-holes dug. After
the barrier is formed, it should be inspected daily and kept in
good repair. This will not require much time, and should not
be omitted. Perhaps no other repair will be necessary than
the addition of a small amount of tar, kerosene, etc. If the
small grain has been harvested and the bugs are all moving at
once into the corn they may all be trapped and the necessity
for vigilance soon over; but if they are coming more slowly
from the ripening grain the barriers must be kept up a few
days longer. .

4. The farmers should organize during the winter and take
measures toward concerted action before the spring opens. A
committee might be appointed to visit all the fields early in the
spring, to see whether or not bugs are present, the object being
to secure uniform and thorough inspection. If bugs are found,
an early preparation should be made for the use both of Sporo-
trichum and the barrier method.

Although the conditions for the successful spread of Sporo-
trichum are complex and uncertain, yet the necessary condi-
tions are often present, and are apt to occur in any locality at
any time.

The barrier method is simple, and will work in any weather.
When properly attended to it will, so far as our own experience
and observation teach, insure the safety of the corn from the
bugs. The organization of farmers should see that it is used
wherever needed, so that flyers from untreated fields may not
later devastate fields that have been treated. As spring ad-
vances it will be a simple matter to tell. whether or not the
corn is in danger from bugs in the small grain, and steps
should be taken to have on hand enough tar, kerosene, petro-
leum, and salt—any or all of these, as the supply may necessi-
tate.

Whether or not each farmer should care for his own field, or
whether an infested district should be put into the hands of

Phau Res
TAL

Fifth Annual Report. 49

two or three persons, who should be paid to see that the work is
done at the proper time and continued till the danger is past,
may well be left for those immediately interested to determine.

_X.-SUMMARY OF INFECTION DISTRIBUTED DURING 1885,

During the past season infection was distributed in individual
packages as follows:

NUMBER, BY COUNTIES.

NINOS PND ES Bed Ea tee ec Ser oie PR VOME wienaA stl. ot acta: Seen Sees 77
AN TOYG PESHES(OT a Ieee Pa ke a Alte A NECR ELSON x2 sn. fil. on the eee ee 20
ANTAELOIELON TA OSI oe ne mL eee Aya WIV ARTOM Stays sects ope es ae 59
LETH Galas Sha Genet ae Un ae ce HP tol Negrsesireall Dey a yh sunk ah og Me eer ene A co 132
VOID een ete clad tt deeg) hw Ge ESAS oe Weta wes. hes ace Mice wang 1
IESRON AT cipal ta eae gage Ny eas a ae ea ATV la; J Gree Wa meee Pea Teer le I 23 22
TUM ETE Tey cane tecawycty we Ys ac ititie nan Uy te oe RANG he Mees daw ett ie yea it deine 18
‘OUTS Sel st ATR MOAI coherent ae a aia a Om One Mont oomeny... 2 kui tig ae Meee 94
cS hel 00 Ca Ta) Bea MLORTIN. Mite ancy acre ae Ie, Be 20
\ GHD EYi01 (St SLA Rg a Na A OMe | eG tna etal ses ines teen ak ee leads 41
De MN PAC ent alu aca ey § Aas MOU Ss es Aig Ok Ree ae eee 2
(Cilla ets Sais Phar aa a ae a OUR IMINGOSH OR eee a he ieee ate ee 70
(ETE aT pa i a a Pee HAG OBA eS. OM) oe eae Ot Regent 80
COIS BA ae 08 a a Ho ORbOrne, Ses, ccs Ie oe ene 16
\AFENTI ROTC OCR aT hea a en are SThsli Oita ceatesteidis aio, okey aed enone 19
Pruitt sees os he ee OF le Pinillipgsctes, S49 a ote ae ree 6
MPC LIMISOTI el ashi eG igs ate IJGo | eOthawatOomie ses stiy. ee eens 86
ELIE Ee Pe Sneed Go diss bts a DS EROELCHS. 1. Sie) esd 2 4 Hel ae rae ME as 25
OITA Mee ee 2 hi ek ca vals tn OOH MOVE DUD UIC. gti vie tia Maclean tee 17
JSC liye FENDI ae a a ee TEE higl bush eC ee ay ae RN A ate 58
IEE eee re oN ee te cil, 2, 3M TERE (25 al kA ia PPR SIA 29
TELUS OT 1 a V VR a cee OP ECOOK Sia ates ap hanick «kee Lee pee tee te 5
I OTRC |: Ge UL ge AE Ba erent ee a AUESI eel ary 61 Te5 I pega ORM ER | aan mL AUER De tr oh 9 14
Hi AMIN y erste eR La ente wore: GSH oalimSQleN Tes aay yet has eee dae 33
DT SES Rb i ee a Ba. MISCO SWAG Sat ars acesiang cece eae 49
Mreenwoodewien co da Sie ou ee Gd WO awnees a arate late ere 100
RAMU alee sts foie 4 gee ws aro winye AT AN CSSEIRRG LD ie Whe ea atl ts Oreo lee renee ili
JIVE) e300) AO ROE rot Rg le QOS ota lLOr esse sine wepsessns een cre tee ee 3
VEL EL EST CE A OS a ma HOSE SUMING cr leet cris oni aoe cic Mase ae 34
Reema rete ch el tek Alle Rey ak dN Ler el Dn Ceyexo Ve ateca tie scat ge MM aOR ER Bek Rea va 2
PLO UMISO MMS aie easier, tae tenet Ot: 408 Wa DaUNSCe =. los ial sae eae ee 59
ST ELI Re, SE GR aa SR Ae Die Wr SILOS, cys Sallis a hers Lak te 74
LEN oF aie Fe RS ORM ea ec ele 6 aL a G2 ia ta Wall BO mi eer ei Tae LANE one ears 25
MBBAV OM WOE. Soul siiiy. ecbaSiai sdvele wate OSCE IGOUSOD Alix Aachen ee 32
TT LE Re SIN na ea a BS SN VAMGGEIC.:. vativca cs eek ue ote ee 38
A Lint aig) As Mee ae Oa bl i 26 Ihab cio erindiatua hy ths po kiieae 3,006

«

50 _ Contagious Diseases of the Chinch-bug.
Number of individual packages sent to other states : Meee ehe
PANTISATUSELS cys Moab Ky saat ede hein BO OTTO OM ETE Mla ule) aL naR ne 10 at
ROUTE OPTIMA Myke ra 2.) eye UA Hate NS AL |\i SPOTTERS ES Nel Roe ATC ANN IS Be eer ge 10 Sat
indian, Territory sy pene 95) Meng ii N38 beth se A Biel an eae 14
TRUSTISTS(GND Wes A ANB GNR SUEMSS UE Man escity ARSIR AE dd AOO i Vermont. ee Leela ama e 1
ELUM ato f=] gn i RR cet AIS Pa GUA PA) oo Var otiada aes A ee eee ae 1
LIC LS DRM A eth Rn Ate Oy ere AN | WSO Sin is ieee Oe an Ral a 10
oy italic CaN aga ; ORAM TL ee Aes 1,040
entuc Dishca oC alaas gt MEN et eas Individual packages sent in Kas., 3,006
iiraMesO Taha, Neae. |S ete ee Reekuae tr a 1
Mcbrasieays 0 ie oN eee 95 Total number of individual .
Oiemomia wok AWM RSet 238 packages sent out......... 4,046

The number of packages sent out in bulk for distribution was

as follows:

IN KANSAS, BY COUNTIES.

GURDON!) 55...) 4). 208 Fort Scott. ranking aes: 112 Ottawa.
MS UG LST Ma Braet aE 83 El Dorado. Greenwood ...... 50 Eureka.
Chautauqua...... 100 Elgin. Marion ji wee 125 Peabody.
MOE Hare Ok he yale 50 Clay Centre. | Montgomery..... 125 Independence.
WIOUE Mos yseuite. 2 50 Concordia. Pottawatomie.... 100 ——
KSOWIBY ML ne etek 100 Winfield. Roce she 500 Little River
@rawiord: rs 2... 15 Cherokee. and Lyons.
Doniphan......... 100 Brenner. Wilson iia o kuue 50 Fredonia.
1B Yori teg Cao pea OR 265 Bond. Paral wc 2,933 }
MN sworthy sees... 200 Ellsworth.
IN OTHER STATES.

MVE FASGOUET, aks oes eye Cliath late beg he NTE Ne ae ret AU alte 200 Bethany.

Rar Re LEV Lia 88 SI ae UR gag a eS EER rao Ae 250 Independence.

Ss MP ROA ia ee vent taboo: Wee dB diene Cue Hd csanitr Be 150 Mount Vernon.
MEO TST iste 8 ee ws eee get cane Ee eke We eleva te 72 Bushton.

(rach aummeag. Sati: oy RA RU arg 50 Lafayette.
Experiment stations, 4 Ren turebeye yo uo st at hee ae Et aa 50 Lexington.
| Nebraskeey 74) f .0i ail suede. oe 120 Lincoln.

Cte OTE ee a eo Ae ete ates eee LON Mar 100 Pawnee.

Mf Noy 2 ke aU ARO Fa ee AM A A AEE Ye SENATE A atl A pas 992
Packages sent out in bulk in Kansas..............-...... 2,233 ;

Total number of packages sent out in bulk. ......... B.225

Total number of packages sent out, individual and in bulk,
Hy atl.

*

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EXPENSES OF THE EXPERIMENTAL STATION.

April 6, 1895, to January 30, 1896.

Paid for materials and supplies in laboratory:

Meyerhoffer & Wilder, fruit-jars, potatoes, and corn........ $31 40
EK. R. Learned, tin and sheet-iron utensils.................. 25 05
C. A. Pease, corn-meal and potatoes....................... 1 20
W. C. Stevens, case for sprayer, $2.40; telescope for camera,
SSPAI( OS ean eC Rn edey auee a at aR UR TUS SCAN i tes Ban Bn a a a 4 90
Wii tcomb,y4 doz. tlower-potss si.) Sx cer. ook oe ae 1 45
B. W. Woodward, 2 atomizers, $2.50; drugs and bottles, $1.. 3 50
MrOowWeaver, cotton andelothi.... .h-0 i.e ose vee es ew wate 1 80
R. L. Stewart, cotton batting, 40 cts.; glucose, 5 cts.; atom-
LACT MLO ELAN apie eee «wee Oe Erte testa Lions shat ahs ey Bhd) aay hes 5d
MAC GIGKO. /NATGWATLE. |e) sc Mya) laee chloe t iawale yp de se 25
RECHT Dall MI OMACASTMMOS : hit fen lal sfsdgaitan elsisrrepeiaieverw Sere fease dat yea)
Richard Kny, Zeis microscopic apparatus .................. 63 85
MoOchestomeptical, Company... se .s4 a. soba ce bce bein cle ed 180 36
Paid for office supplies:
R. L. Stewart, paper, lettering angles, and note-books...... $1 80
gournal Company, two record-books.......:......-....22.55 6 00
Paid for extra office help:
TBS, [BS RU ICEL EST asaVo) 1182s ae a Ee tr ane cet ge ae eo Ta $49 98
1h, LOW SHTERW ETAL Bo Dk iat iinta te alec eae ete a hae Ee ar eI Nee gem 157 00
Fee Wan O) MABIOREOL ert oie ae vel oe ue Se Se Viton RP LSA RIOR eevee a Liebe 9 50
DM ENON CLE SOMe myn eee p tee ny ies cores bre Do alccish g uuckolanatotuse ls fleie eye 1 85
Paid for field agents’ salaries and expenses
Aree CN VLE CV Ge Hee RROD Site Ws Cotes MCS sueista ais trait Miele airdeey $188 77
Gi SOLS Vos a yo tia 1 ees aa EN a a PR Aa alr (ss
PARR SAR DOT EEO cra Salita ah mM Oy Mia Guia aM pitas 7 60
RVG MS TOV OM BR tir reat Stier) sone etd ste NECA gig. co eteysi sacle e: hace 16 30
UPR NEES TY CONV acta ENED hw Mattar ud Getic UNL Neca oe 32 30
Paid for labor in laboratories:
JEL” SUSE Ded beta i gel anette or ae gam ns PUR A iy An aL a eR STE $10 90
ERS Tie AS Tieng eet AWM, ANC: to WMA css SEE BARS IRE SANS a aS I 60
MiRMAM UE arber ial ions ssi soe als: See ai Ua NPRM ee Ab Gee 199 98
Wes TR taVe Een gs Oh ap Soe Oia RON es SUT eaten pee eT A Ee ee 9 00
BENG OME ITEVE LG anes Ciinveh ne ber ) ohdetes Lei paklocl ANIL ANS Oat ki 15 00
Hy, VERT Tra Ut A ST i eT Ua ea EP ee 5 00
[CE GINI ATE. 7/pa ht GM SSA a a a eT a Ro a 71 80
Top UNTO Thay at ypBless wali Se seule Ue ate een ne ag et on De Rt 26 25
- ein
(51)

$319 86

218 33

338 53

¥,

ete treet eee eee

Directions for Obtaining and Applying the Chinch-bug
Infection.

Infected bugs will be sent to. anyone on application.
The infected bugs received from the Station should be used
to start infection-boxes in the following manner :

CHARACTER AND LOCATION OF INFECTION-BOX.

Make a box of seven-eighths inch material (matched white
pine is best), about 24x36x6 inches. Make the cover tight-fit-
ting, so that the bugs cannot readily escape. Weather-strips
tacked about the upper edges of the box, so that the cover
presses tightly against them when closed, will be found of ser-
vice in keeping the bugs in. A heavy chalk-line drawn inside
the box on the sides near the upper edge will greatly assist in
keeping the bugs in the box.

It would be well for each farmer to have two boxes, and, after
the first box has become well started, he should start the second
from infection obtained from the first.

Place the boxes so as to exclude them from the sun and wind.
A basement room is a good location.

TO START THE INFECTION IN THE BOXES.

Sprinkle the boxes thoroughly with water inside and out.
Place an even layer of garden-soil in the boxes, half an inch
deep. ‘The soil should be free from leaves or anything liable to
decay. Sprinkle the soil until it is moistened through, but not
muddy. Put athin layer of green wheat or corn over the soil
in the boxes, and distribute over this, at regular intervals, five
or six of the white-fungus-covered bugs. Now put into the
boxes healthy bugs from the field until they are somewhat
crowded, but not packed over one another. Lastly; close and
fasten down the cover.

Examine the boxes daily, and sprinkle the sides and soil as
often as they appear to be getting dry. Do not, however, make
the soil muddy. As soon as the white-fungus-covered bugs be-

(53) |

a) i MR AR A ale

54 Contagious Diseases of the Chinch-bug. = det
gin to increase in your boxes, you may commence to gather
them for the infection of your field, but not before. Youshould ~_
be able to do this in three or four days. Always leave afew _
fungus-covered bugs in your boxes for continued infection. Re-
place the green wheat or corn as often as it becomes yellow, and _ kin

keep the boxes replenished with healthy bugs from the field.

\

TO INFECT A FIELD WITH THE WHITE-FUNGUS DISEASE.

After you are made certain by the increase of the number
of bugs covered with the white fungus that the infection is oe
working in your boxes, you should gather from the boxes dead
bugs and live bugs, white-fungus-covered and non-white-fungus-
covered, and scatter them in the field where the bugs are the
thickest, in the axils of the leaves and at the bases of the stalks.
If the fungus-covered bugs are abundant in the boxes the earth
might be taken from half of the boxes together with the bugs
and scattered in the field. The earth should be replenished as
often as removed. You should always take care, however, that
some white-fungus-covered bugs remain in your infection-boxes.
As fast as the bugs are taken from the infection-boxes they
should be replaced by fresh bugs from the field. Continue to
scatter bugs from the infection-box over the field at intervals of
two days or less, until it is seen that the bugs are dying rapidly
all over the field. (

CONTINUED CARE OF BOXES.

If after a time the boxes should give off a smell of ammonia,
from the decay of bugs or bits of wheat or corn left in the boxes,
the boxes should be cleaned out, earth and all, and, after airing
a day, started anew as at the beginning.

Keep the earth in the boxes moist, but never make rt muddy.

Sometimes other fungi than the white Sporotrichum appear
on the bugs in the boxes. The only annoying one likely to ap-
pear is a yellowish-brown one known as Aspergillus. This
fungus does not kill the bugs, but it may take possession of their
dead bodies and become detrimental to the growth of the white
fungus. If the Aspergillus should appear extensively in the
boxes, clean them out and burn hay in them, to kill the spores,
and then start the boxes again as at the beginning. |

GENERAL REMARKS. _

1ould save a quantity of the white-fungus-covered bugs
These should be put away in —
cept dry and above a freezing —
The fungus will remain alive in the bodies of
bugs for a year at least. Should the first lot of infected
bu from this Station seem to fail in their purpose, send with- “he

out delay for a new supply. Yi :

ote carefully the chinch-bug conditions in neighboring fields, M,
urge your neighbors to use the infection. ‘aaa

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