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THE

MOIfMNA STATE BOARD

Ol^NTOMOLOGY

FIFTH
BIENNIAL REPORT

Vo

1922-1923

IjSfn?'^'^ Library

THE MONTANA

STATE BOARD

of

ENTOMOLOGY

FIFTH BIENNIAL
REPORT

1922

1923

MONTANA STATE BOARD OF ENTOMOLOGY

W. F. COGSWELL, M. D., Secretary State Board of Health,
Chairman, Helena, Montana

W, J. BUTLER, D. V. S., State Veterhiarj Siu-geon,
Member, Helena, IMontana

R. A. COOLEY, B.So., State Entomologist,
Secretary, Bozeman, Montana

LETTER OF TRANSMITTAL

Bozemaii, Mont., January 1, 1923

To His Excellency. Joseph M. Dixon.
Governor of Montana,
Helena. Mout.

Sir :—

Acting for the Montana State Board (»f Entomology, I have the honor
to transmit to you the P'ifth Biennial Keport.

In the preceding report of the Board, attention was directed to the
developments in the work which had made it evident that above all else
intensive research was needed, in order that we might secure informa-
tion concerning the real source from which ticks become infected with
Rocky Mountain spotted fever. The legislature, however, was unable to
make the necessary appropriations for which we had asked, thus placing
us in a difficult position. Fortunately, developments in the fever situa-
tion in the Bitter Root Valley in the early part of the season of 1921
led to the coming of the United States Public Health Service with a
fund to be devoted to research studies. It has, therefore, been possible,
by arrangement between the Board and the Public Health Service, for
the latter to take up the. investigational work on a satisfactory basis
and at the same time for the Board of Entomology to continue the de-
struction of rodents which it has been shown liave much to do with the
abundance of ticks in the valley, and to carry out other control measures.

It should be pointed out that, while the situation in the Bitter Root
Valley has been distinctly relieved, there has as yet been very little
accomi)lished toward the actual eradication of spotted fevei*. There can
be little doubt that the real source of difficulty is back in the mountains
which border on the valley and that there exists a set of conditions little
understood at present which are responsible for the continued existence
of spotted fever in the floor of the valley. Nevertheless, much informa-
tion of value has been accumulated which, while not of direct value for
the immediate control of the disease, is a necessary preliminary to in-
telligently conducted and effective eradication.

Very respectfully,

R. A. COOLEY. Secretary.

FIFTH BIENNIAL REPORT OF THE STATE BOARD OF

ENTOMOLOGY

By R. A. COOLEY, Secretary

Previous to tlie bieiiiiiniu now closiniii, tlie efforts of the
Board of EntomoloiiT had been devoted almost exelnsively
to the eradieatioii of the spotted fever tudv, Dcntiacoitor
veniistiis Banks, in western Montana. In onr report of
two years ago attention was called to the neeessity for be-
ginning rather extended research work into the conditions
in nature which favor the continued presence of the spatted
fever organism among rodents or other animals in the
mountains bordering on the liitter Root Valley. The legis-
lature was asked for sufficient funds to enable us to take
up this study and at the same time to continue the work
of rodent di^struction which was well under way. The
legislature, however, found it impossible to nnike as large
an appropriaton as was necessary, an<l in the spring of
1D21 the Board of Entomology laid out its work to mak(»
the best use possible of the nu)ney that was made available.
The investigation work was started, though on a restricted
basis, and the control continued on a less extensive scale
than in previous seasons.

During the spring months of I'Jl'l tliere ^^■as a sharp in-
crease in the number of cases of spotted fever in the Bitter
Root Vall(\v. In 19:20 there were only four cases in
the counties of Missoula and Ravalli, while in 11)21 in these
same counties there were eleven. Certain pronnnent citi-
zens were stricken and tlie public became tJioroughly
aroused. An unusual interest in the disease and in the
w^ork of this Board became evident. An appeal was made
to the United States Public Health Service for assistance,
and on the invitation of the Board of Health and tlie Board
of Entomology, this service established a field station in the
Bitter Root Valh\v and started resear(di work. Dr. R. R.
Parker, who had held the title of assistant entoinologist to
the I)oard of Entomology, ^^■as transfericd to the \y\\ roll
of the Public Health Service and placed in charge. IMr.
W. E. Pollinger was employed by the Board and assigned

BOARD OF ENTOMOLOGY 5

to the work of rodent coutrol, thereby leaving Dr. Parker
free to devote his attention mainly to the investigation.
Dr. Parker was in charge nntil the arrival of Dr. R. R.
Speneer, past assistant surgeon in the Public Health Serv-
ice, who was sent to Montana to take charge of the labora-
tory in March, 1922. The coming of the Public Health
Sendee into the fi(dd resulted in the taking up of the in-
vestigational A\()ik along even more extensive lines than
would have been possible Iiad the full amount requested
from the legislature been made available. A large school
building on the Avest side of the river near Hamilton was
rented by the service and a lal)oratory with the necessary
equipment was established. The work is now being con-
ducted in tliis l)uilding and it is our hope that this service
Avill continue its Avork for some years, or until it is com-
pleted. The funds from the State of Montana are being
devoted to the contnd work, mainly, and to a small extent
are used to help pay certain necessary expenses connected
with the research work that can not be charged against
Federal funds. Tlie A\-ork is well organized and is being
pres-^ed with much energy.

Tlie work of controlling rodents and of dipping animals
must be continued, but in the light of the experience of the
Board it is apparent at the present time that our interests
must center around the research work, for it is evident that
until we know the source from which the ticks become in-
fected and the factors that perpetuate the disease, we can
not do a work of permanent value. The report of Dr. Par-
ker and Mr. Pollinger is given in complete form since it
furnishes a full summary of the work that has been done
during 1921 and 1922.

THE OCCURRENCE OF SPOTTED FEVER IN MONTANA

During recent years a considerable amount of attention
has been given to accumulating reliable data on the num-
ber of cases of Rocky Mountain spotted fever throughout
the State of Montana. It should be borne in mind that
there are two types of the disease in the State. A severe
type with a high percentage of fatalities prevails in Mis-
soula and Ravalli counties. A less severe type of infection

6 FIFTH ANNUAL REPORT

occurs in other parts of the State, particularly in the coun-
ties east of the mountains. This milder, though by no
means not-to-be-dreadecl type of the disease has been grad-
ually spreading and the number of cases increasing. At
present it is known to occur in at least twenty-eight coun-
ties. The mortality rate of this type A^aries with the local-
ity, but is rarely under 10 per cent and during some
seasons is much higher. Although it has only been defi-
nitely known in eastern Montana since 1914, residents in
certain sections have already learned to fear it and it is
becoming more and more common to hear people threaten
to move to areas where the infection is not known.

In 1922 there were eight cases, all of them fatal, in Mis-
soula and Kavalli counties, while fifty cases with a mor-
tality rate of over 15 per cent occurred in other sections
of the State. The following tables show the number of
cases in Missoula and Ravalli counties since 1913 and in
other counties since 1911 :

BOARD OF ENTOMOLOGY 7

Rocky Mountain Spotted Fever Cases in Counties Other Than

Missoula and Ravalli Beginning in 1914, the First Year

That the Disease Showed a Wide Distribution

Within the State

Counties
Blaine

1914

1915

2
3
4
1^
6

2

5

2

1

4

3

2

35

1916

1

1
3
1

6

1
1
1

15

1917

4

3

1
1'

1

1

2

3"

19

1918

2

1
2

1"

6

1919

1
1

i

2

1
1

i

1

9

1920

1
1
1

3
1

3
"lO

1

18

1921

1

1"

3

1
1

1

2

2

5

17

1922

1

Broadwater

Big Horn »

Carbon -

2

0
1
3

Carter

Cascade ^''

Custer ■•

i

Dawson

1

Fallon

2

Fergus ^

6

Gallatin"

Garfield . . .

6

Golden Valley

Granite"

Jefferson

Lewis & Clark...
Madison

1

i

McCone

Musselshell

1

8

Park 1"

Prairie

1

Richland

1

Powder River " ...
Rosebud

4

Stillwater

Treasure

2

Yellowstone '^

Valley

10"

Totals

4

49

» Two doubtful cases in 1901.

2 Seventeen cases between 1894 and 1904; records between 1904 and 1914
incomplete.

^ Brought in from Idaho.

*U'nceitain occurrence before 1915.

* Doubtful case in 1904.

° Locality of infection doubtful.

' Brought in from Idaho.

'Earlier cases between 1891 and 1904.

' One case uncertain.
"Doubtful case in 1904.
"Uncertain cases prior to 1915.
'^ Uncertain case.
^* Uncertain case in 1904.
'* Two cases brought in from Wyoming.
^^ Two uncertain cases in 1900.

'"One of 1922 cases may have come from Stillwater County; another was
imported from Wyoming.

" Imported from Nevada.

Rocky Mountain Spotted Fever Cases in Missoula and Ravalli
Counties from 1913 to 1923

County 1913 1914 1915 1916 1917 1918 1919 1920 1921 1922

Missoula 5 5 1112234

Ravalli 73552328 4'

Totals 11 12 8 6 6 3 5 4 11

' One of these was infected in the laboratory.

S FIFTH ANNUAL REPORT

THE IMPORTANCE OF ROCKY MOUNTAIN SPOTTED
FEVER IN MONTANA

There are other diseases prevalent in Montana which are
responsible for more sickness and more deaths than Rocky
Mountain spotted fever, but this disease, because of the
fact that it is not fully understood and because of the
high rate of mortality in the western part of the State is
responsible for a dread of the disease in the public mind
which seriousl}' affects business interests and property
values. There can also be no doubt that the presence of
spotted fever in Montana is responsible for much misunder-
standing, which is very injurious to the State in other parts
of the United States. Once the disease is fully understood
and effective measures of control and prevention become
known, the situation Avill be materially relieved. However,
conditions are such that ]Moutana should give all possible
attention to solving the problem as rapidly as possible.

CO-OPERATION OF THE UNITED STATES BIOLOGICAL

SURVEY

As in previous years, the Biological Survey has this past
season co-operated with the Board of Entomology in tlie
poisoning of ground squirrels on the Bitter Root National
Forest bordering on the Bitter Root Valley and also on
other public lands. This has been of great assistance to
the Board and we are pleased to express our appreciation
to this service for the help which they have given.

MISSOULA DISTRICT

During the spring of 1922 the commissioners of Missoula
County requested of the Board that control work be started
in the LoLo Valley and in the main valley to the north.
A fund of |3,000 for this work was made available. Ac-
cordingly, the Board of Entomology, acting under the law
which created it, declared an additional control district as
follows :

'North Boundary — The east and west extension of tlie
township line between townships 13 and 11 north, begin-
ning at the point where this line intersects the Clarks Fork
river, thence extending westward to the Montana-Idaho
State line.

BOARD OF ENTOMOLOOY 9

East Bouudarji — The Clarks Fork river from its iutersec-
tiou with the north boundary, south to the junction of the
Bitter Root and Hellgate rivers, thence soutli along the
Bitter Root river to the [Missoula-Ravalli county line.

SoutJi Boiindanj — The east and west extension of the
Ravalli county line from its point of intersection with the
Bitter Root river Avest to the Montana-Idaho State line.

TTV.s'f Boiiiidari/ — The ^lontana-Idaho State line.

10

FIFTH ANNUAL REPORT

WILLIAM EDWIN GETTINGER

Boru, July 1(1, 1899.

Died, Jnne 30, 1922, of IJoeky ^Mountain
spotted fever, contracted while assistiiig in the
investiiiation of the disease at Hamilton, ^Mont.

BOARD OF EXTOMOLOCxY 11

DEATH OF WILLIAM EDWIN GETTINGER

The Board of Entomology is iiuder the painful duty of
recording the death of yet aiiother person engaged in a labo-
ratory investigation of Rocky Mountain spotted fever, Wil-
liam Edwin Gettinger contracted the disease by some un-
known accident on or about June 15, 1922, while in the em-
ploy of the Public Health Service and died after an illness of
eight days. Mr. Gettinger is the fourth person to die as a
result of spotted fever infection contracted while on duty in
investigations intended to increase our knowledge of the
disease and save the lives of other human beings. Five have
died, if we include Dr. H. T, Ricketts, who died of typhus
fever contracted while investigating tnat disease. This in-
vestigation, however, was undertaken on account of the simi-
larity between typhus fever and Rocky Mountain spotted
fever and was really a part of the spotted fever investiga-
tion.

In full knowledge of tlie danger to Avliich he was sub-
jected and yet without hesitation Mr. Gettinger entered the
work with enthusiasm and continued it with devotion. When
he knew that he had contracted the disease he faced the situ-
ation with the utmost courage,

Sucli is the course of true heroism. Always making light
of the danger or keeping silent, yet always aware of it, he
devoted himself to his duties with energy and ever-increasing
skill. When the nature of this obscure disease is full}^ known
and the way is discovered to prevent other human beings
from being infected, it will be recorded of William Gettinger
and of those others who in like manner have sacrificed their
lives in the study of this dread disease, that each was a
martyr to the achievement.

12 FIFTH AXNT'AL REPORT

FINANCES

Tlie spotted fever work is necessarily a e(niiltiiiation of
investigation and control. As fast as information is ob-
tained it is appliel in control. We aro receiving from the
State the snm of |1>,00() annnally but this is supi)lemented
by the funds from the United States Public Health Service
and by certain sums from the county and further by actual
costs of rodent control returned by the property owners
through the taxes under Chapter 27 of the Sessions Laws of
1919. Following is a statement of the sums used by the
Board of Entomology and the Federal Public Health Service
in the work in the biennium now closing:

state appropriation for four months to July, 1921..^ $ 4,200.00

State appropriation, July, 1921, to July, 1922 9,600.00

Public Health Service allotment for investigation, September, 1921,

to July, 1922 - 20,000.00

Ravalli County for ground squirrel control, season of 1921 2,450.0o

Red Cross in Missoula County for research expenses not chargeable

to Public Health Sei-vice funds, July, 1921, to July, 1922 1,400.00

Red Cress in Ravalli County for research expenses not chargeable

to Public Health Service funds, July, 1921, to July, 1922 800.00

Populai- subscription in Ravalli County for research expenses net
chargeable to Public Health Service funds, July, 1921, to July,
1922 600.00

Total in 1921 $39,050.00

State appropriation, July, 1922, to July, 1923 $ 9,600.00

Public Health Service allotment for investigation, July, 1922, to

July, 1923 26,000.00

Missoula County for ground squirrel control in Missoula District,

season of 1922 3,000 00

Ravalli County for ground squirrel control, season of 1922 2,450.00

Red Cross in Missoula County for research expense not chargeable

to Public Health Sei-vice funds, July, 1922, to July, 1923 1,400.00

Ravalli County general fund for research expense not chargeable to

Public Health Service funds, July, 1922, to July, 1923 1,000.00

Red Cross in Ravalli County for research expense not chargeable

to Public Health Service funds, July, 1922, to July, 1923 400.00

Total in 1922 $43,850.00

The State funds are applied mainly to the control or to
the alleviation of tlu^ situation so fai- as is jjossible under
the present state of our knowledge. Tlie investigational
work is under the direction of the United States Public
Health Service and under their funds.

The Board of Entomology has api)roved i(m] nests for an
increased appropriation from the State whicli has been filed
with the Secretary of State. It should be pointed out that
the care of health is a State charge, especially where a

BOARD OF P:NT0M0L0GY 13

inoiiaciiiii- situation is as oenoral as is tliat of Kooky Mouu-
tain spotted fever and where tliere is danger that the fever
may spread and produce a most serious condition. We can
not, with any justification, let up on the control work.
Rather does it need to be intensified. At the same time it
is not just that the entire expense of rodent destruction on
a jiiven piece of land should be paid by the owner or renter.
Chapter 27, session povrers of 1919, authorizes the Board to
destroy ground squirrels wliere the owners fail or refuse to do
so or in cases where the owners prefer the State to do it for
them and charge the expenses back to the land at not to ex-
ceed five cents per acre per treatment. This has boen due for
the past four years. It has become evident that a continua-
tion of the work in the persent manner is not going- to perma-
nently eradicate the squirrels. They are abundant ou all
sides of the control districts, in the mountains west of the
valley, and in the valley between the districts and the river.
Again, there are pieces of land on Avhich five cents per acre
per treatment is not nearly enougli to do the work effectively
and some squirrels are accordingly left to multiply and
spread. The land owner is left with the prospect of having
to keep up the expense year after year. In the increased ap-
propriations asked for it is contemplated that the farmer
shall be relieved of a part of the expense and that the State
shall spend such additional amount as is necessary to secure
an effective nu^asure of control.

Many farmers wish to avoid the expense of fiv(^ to ten
cents per acre and, therefore, attempt to do the poisoning
themselves as allowed by laAv, Some do not try to do thor-
ougli work, while others with good intentions fail to secure
results. A reduced cost would mean that more of tlie work
could be done by the State, which with its trained and ex-
perienced men can do it more effectively.

Furthermore, the work of control should be extended
farther up the valley in the vicinity of Darby. The residents
have requested it and the need is evident. This calls for in-
c rea sed expend i ture.

ORGANIZATION AND PERSONNEL

The Avork on spotted fever is organized under an effective
and verv satisfactory arrangement betAveen the State and the

14 FIFTH ANXIWL REPORT

United states Public Health Service, of wliicli Dr. Hugh S.
Gumming, surgeon general, is chief. Dr. R. R. Spencer,
Surgeon, is in charge of the field station at Hamilton, and
Dr. R. R. Parker, formerly assistant entomologist to the
Board of Entomology, is now on the staff of the Public
Health Service and is in charge of the field investigations.
By this arrangement continuity with the previous investiga-
tional work of the Board of Entomology is obtained. The
laboratory is organized as follows : ,

Bureau of the Public Health Service, Research Staff

D;r. R. R. Spencer, Surgeon, United States Public Health
Service, in charge of station.

Dr. R. R. Parker, special expert in charge of field investi-
gations.

William E. Gettinger, former laboratory assistant (de-
ceased).

Lawrence H. Dunn, assistant entomologist.

O. M. Salisbury, field assistant.

George H. Cowan, fiekl assistant.

Elmer Greenup, laboratory attendant.

Maud A. Hougidan, clerk.

George H. Micliky, janitor.

State Board of Entomology, Control Organization

W. E. PoUinger, field agent, in charge of rodent control.

William Gray, deputy, rodent control, for five months
during active season.

R. H. Gagie, field assistant, for temporary investigation
studies in co-operation with the Public Health Service,

Maud Ai. Houghlan, clerk.

PUBLICATIONS

During the biennium the following scientific publication
has been prepared :

"Transmission of Rocky Mountain Spotted Fever by the
Rabbit Tick, naciiuipJn/saHs Jcporis-palustris Packard," by
R. R. Parker. This appeared in the issue of the American
Journal of Tropical Medicine for January, 1923.

BOARD OF ENTOMOLOGY 15

The results of the investigatioiis by the Public Health
Serviee Avill be printed from time to time in the publica-
tions of that bureau. A paper dealing with certain char-
acteristics of the virus of spotted fever in ticks was recently
published in the public health reports.

16 FIFTH ANNUAL REPORT

REPORT OF TICK CONTROL OPERATIONS IN THE

BITTER ROOT VALLEY DURING THE SEASONS

OF 1921 AND 1922

R. R. PARKER, Ph. D.,

Assistant Entomologist, Montana State Board of Entomology, until

September 19. 1921

Special Expert, United States Public Health Service, since
September 19, 1921
and

W. E. POLLINGER. Field Agent,
Montana State Board of Entomology since November 1, 1921

During the present Inenniuni important clianj^es have
talven phice in the methods of Rocky Mountain spotted fever
control and in the manner of its conduct. These changes
have been dictated in part by limitations placed upon the
work by inadeciuate funds and in part by the initiation of
long-needed rei^earch studies. In the latter field, the work
was undertaken in a modest way by the State Board of
Entomology, beginning in April, 1921, and continued until
September of that year, at which time the Federal Bureau
of the Public Health Service entered the field and assumed
the burden of the major research problems. The service is
now conducting the most comprehensive investigation of
spotted fever yet undertaken.

Since Septenil)er 19, 1921, the senior writer has been in
the employ of the Public Health Service and has been asso-
ciated with Surgeon R. R. Spencer of that Service in the
research studic^s. Througli the courtesy of the Service he
has been permitted to supeiwise the control work, the junior
writer, however, being in immediate charge.

At the last session of the legislature an appropriation of
|22,530 was requested. It was considered that this sum
would be sufficient to greatly increase the efficiency of the
control procedure and at the same time provide an amount
which would permit the starting of much needed investiga-
tion studies. (In requesting this money the fact was
emphasized that an increase in cases was expected during
the seasons immediately to follow. That this prediction
was not without basis is witnessed by the fact that during
1921 more cases occurred in tlie Bitter Root Yallev than

BOARD OF ENTOMOLOGY 17

for seven years, and that in 1922, the State, as a whole,
had the largest unniber of cases in the histiiry of the disease
within its borders). The sum allotted, however, was but
slightly more than half that asked for control purposes
alone. A radical change was necessary, then^for;', in the
working plans in order that the money provided might be
expended to the best advantage.

In the Fourth Biennial Report, pages 19 to 21, an out-
line was given of the control program which it was i)ro-
posed to put into effect, and the reason for each method
of attack. This plan involved no new methods but was
simply an attempt to amplify and intensify to a point of
greater efficiency those already in use. The following main
lines of work were to be conducted: (1) Kodent control;
(2) grazing control; (3) dipping; (4) quarantine; (5) the
handpicking of dairy stock and work horses.

Since the funds allotted were so inade(iuate a drastic
cliange in the control program was necessary. The rodent
control as emphasized in i>rcvious reports is the major or
most important line of work, the other measures being
considered as accessory methods centering around it. In
restricting the activities, therefore, it seemed best to center
our effort on this phase witli the idea that rodent control
reasonably well done would at least give as good results as
an attempt to caiTy on the full program with only the
means to make it partially effective. It was felt that while
this change from the full program meant a lessening of
efficiency, yet it would be possible, nevertheless, to at least
prevent conditions from going backward. Furthermore, it
was possible to avoid the employment of district deputies,
of whom five were employed in 1919 and tliree in 1920.
The expense of auto and horse hire for these men was also
eliminated. Only the services of Mr. Gr. H. Cowan, chief
deputy, were retained. The regulation requiring the hand-
picking of stock was retained, although without the district
deputies, its execution depended entirely upon tlie in(dina-
tion of persons concerned. The quarantine regulation has
also been enforced. The enforcement of the latter regula-
tion is important in that it is of value in preventing the
shipment of stock carrying infected ticks to other parts of
the State or to points outside. Such vats as are in repair

18 FIFTH ANNUAL REPORT

were filled to permit the dipping of stock and for use in
connection with quarantine work. The rodent control is
the only phase requiring extended discussion and is con-
sidered in some detail in subsequent sections of this report.
These changes in the control procedure permitted that a
small part of the appropriation be expended for the initia-
tion of a line of investigation, long contemplated, to seek
out the factors that are responsible for the maintenance of
the virus of Rocky ^Mountain spotted fever in nature. That
such studies would be of real value was soon demonstrated
by the discovery that the fever is not onl}- transmitted
among rodent life by the fever tick, Dermacentor venustus
Banks, but also by the rabbit tick, Haema'pliy salts leporis-
palustris Packard. The funds available for this work were,
of course, limited and it is indeed fortunate that the Pub-
lic Health Service was able to come into the field and de-
vote more ample funds to the solution of the problem.

EXPANSION DURING 1921 AND 1922

During the season of 1921 no attempt was made to ex-
pand the work. In 1922, however, at the urgent request of
the commissioners of Missoula County and the solicitations
of the residents in the area concerned, the district in that
county was extended to include all the territory- between
the Bitter Root River and the ]Montana-Idaho State line,
and between the Missoula-Ravalli county line on the south
and the north end of the Big Flat on the north.

Of this area active work was necessary on approxinmtely
65,000 acres. This total includes the former O'Brien Creek
District of about 15,000 acres. The area on which w^ork
was actually performed was increased by about 58,000
acres, the total area now under actual control being ap-
proximately 200,000 acres, of which about 145,000 acres are
privately owned land.

The inclusion of this territory within the districts makes
the control areas continuous for the first time, the districts
now extending from Lost Horse Creek on the south, to the
Big Flat west of Missoula on the north, a distance of about
sixty miles ; and at one point, the LoLo canyon, tlie districts
extend thirt}' miles westward to the Montana-Idaho State
line.

BOARD OF ENTOMOLOGY

19

20 FIFTH ANNUAL REPORT

Tho LoLo caiiycm is included within the tciTitory added
this past year. It lias been known as one of the worst
spotted fever sections, but since the Hoard of Eiitonioloiiy
assumed the burden of control work in 1918, sufficient
funds have never been available to permit work in this
region. The FcMleral lUireau of Entomology conducted
operations in this canyon for two seasons, 1915 and 191fi,
but withdrew because of the attitude of the people and
the natural obstaides to control. Since then the changed
attitude of the residents and the different methods of con-
ducting and financing the work have materially altered the
situation.

As noted above, the work in this territory was under-
taken at the earnest request of the commissioners of Mis-
soula County and residents of the area. While it has not
been feasible up to this year to undertake the work, it was
felt incumbent upon us to do so, not only because of the
strong public sentiment which demanded it, but also be-
cause of the LoLo road project. This road will open up
dangerous country to tourist travel and it is incumbent
upon the State to make the territory in its vicinity as safe
as possible.

Two factors made it possil)l(^ to take up the work in this
region : First, an appropriation by Missoula County, and
second, the fact that the Public Health Service had taken
over the major portion of the investigation Axork, thus re-
lieving the Board of Entomology of most of the expense
connected therewith.

FUTURE EXPANSION

A conscious effort has been made to keep control opera-
tions within limits which could be properly cared for. This
has been difficult, however, even though extension has only
been made at the earnest solicitations of persons most
vitally concerned.

There is before the Board at present a request for ex-
pansion southward from Lost Horse Creek to Chaffin Creek,
about four nnles south of Darby. The inclusion of this
area within the districts would bring within th(^ limits of
the latter all the farming country which there is any ap-
parent justification for including at the present time.

BOARD OF ENTOMOLOGY 21

Thus far it has been necessary to refuse tliis request, but
it is recommended that it now be granted if sufficient funds
can be secured to malve the additional effort of real value.

410DENT CONTROL

The rodent control work is conducted under the provi-
sions of Chapter 27 of the Sessions Laws of 1919. This law
has now been in force for four years, and except as here-
after noted its provisions have proved very satisfactory.
It empowers the Board of Entomology to pass regulations
requiring the owners of land in the several districts to ex-
terminte ground squirrels or other rodents at such times
and by such means as prescribed by the Board. AVhen the
owners refuse or neglect to perform the necessary work
the Board is empowered to do same through its representa-
tives. To cover the cost of this delinquent work, the county
commissioners of any county concerned are authorized to
appropriate a sufficient amount from the general fund of
the county. The costs on each piece of land can be as-
sessed and collected as taxes, so that all funds expended
are returned to the county.

Although the eradication of all rodents from the west
side of the Bitter Root Valley would supposedly elinunate
all danger of spotted fever, and although at least ten species
of rodents are known to be susceptible to spotted fever and
capable of infecting ticks, yet this law has only been in-
voked to compel the destruction of the Columbian ground
squirrel. This is for the following reasons: (1) AVhile the
almost complete elimination of all rodents may occasionally
be possible under localized conditions, it does not at present
seem feasible nor financially possible over large areas of
the type of country found on the west side of the Bitter
Root Valley, nor could the land bear the expense of such
extensive operations; (2) when the whole infected area in
the ralJcif proper is considered, ground squirrels feed the
overwlu'lming majority of the inimature ticks; hence, the
elimination of this rodent may be expected to eventually
result in a coiTesponding decrease in tlie abundance of
ticks and a salutary effect on the nund)er of fever cases.
Since this rodent is also a serious agricultural pest there is
a twofold reason for its control.

22 FIFTH ANNUAL RF:P0RT

Until 1921 the rodent control and particularly ground
squirrel control, had been the central control activitj^ as
explained above, while during 1921 and 1922 it has been
the only method employed which has called for finaneial
outlay or considerable expenditure of time on the part of
the land owners. Whereas, prior to this time district depu-
ties, under supervision, liail charge of the control in each
district, employing and discharging their men, assisting in
vat work, grazing control operations, etc., the work has
since been handled from headquarters with the aid of one
assistant.

The extent of tlie work performed can be judged from the
figures in the following tables:

BOARD OF ENTOMOLOGY 23

SUMMARY COLUMBIAN GROUND SQUIRREL CONTROL

RAVALLI COUNTY CONTROL DISTRICTS

o
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urchased
esident

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1919 i$3, 500.00144,3961/2140,5471/312,798 |4,283 |266,611

1 I 1 I I I,

1920 I 3,000.00148,299 |40,983 |2,308 14,395 1209,521
I I I 111

1921 12,250.00148,456.8 138,331 13,025 1/2I3, 703 1242,032
1 1 I 1 1 I

1922 I 2,400.00141,749 |44,401 14,760 |4,091 1380,800

3 17 1.0378 11,2041/2!

1 I 1

2.35 1.0329 1 5221/3I 151

1 1 1

2.79 1.0292 1 515 1 200

1 I 1

4.42 1.0318 11,197 | 344

RAVALLI COUNTY — FARMS BETWEEN CONTROL DISTRICTS AND
BITTER ROOT RIVER

1 1 1 1 1 1 1 1 1 1

1920 1 115.4601/21 - 1 819^1 8281/2! 75,021| 4.85 10393 1 152 1

1 1 ! 1 1 1 1 1 1 !

1921 1 '16,040 1 11,081 11,091 | 86,4801 5.39 1.0473 1 137 1

! ! ! 1 ! 1 1 1 1 1

1922 ! 13,160 1 ! 6I21/2I 249 149,000115.8 1.0713 | 373 | 45

1 1 i 1 1 1 1 1 1 1

MISSOULA COUNTY CONTROL DISTRICTS*

1 1 1 1 1 1 1 1 1 1

1920 '•$ 750.00' 9,670 i.il 8,930 i.il 581 1 901 1 40,905| 2.19 |.0308 1 82 |

1 1 1 1 1 1 1 1 1 1

1921 1 500.001 8,301 1 8,223.1 | 241.9 1 555.5 17,3521 1.0581.0198 1 127 1

1 1 1 ' 1 1111

1922 1 3,000.00'66,532 156,070 16,056 14,811 1484,4801 3.91 1.0231 1 291 1

1 1 1 1 1 1 1 1 1 1

RAVALLI COUNTY— FEDERAL LAND^ IN CONTROL DISTRICTS

1 1 1 1 1 1 1 ! 1 1
1921 1$ 292 211 6 680 1 ' 233 1 1 1 j. 043751 1

I 1 1 1 1 1 1 I 1 1
1922 1 308 961 6 640 1 1 448 1 ' 1 1.046531 1

1 1 1 1 1 1 1 1 I 1

MISSOULA COUNTY — FEDERAL LAND 2 IN CONTROL DISTRICTS

1 1 1 1 ! 1 1 1 1 !
1922 1$ 157.501 3,076 ' 1 200 1 1 ' !.0231 1 '

1 1 1 I 1 1 I 1 1 1

NATIONAL FOREST =— RAVALLI COUNTY

1 1 1 1 1 1 1 1 1 1
1921 1$ 803.40135,000 1 1777 5-61 1 1 1.0229 1 1...

1 I I I

1922 I 493.15140,000 I- I 671

I I 1 I

I I

.f 012321

* Confined to O'Brien Creek District in 1920-1921.

- Funds for Federal land furnished by the Federal Bureau of the Biological
Survey.

24 FIFTH ANNUAL REPORT

The aid contributed by the Fe(h^ral TUireau of tlie IJio-
h)oical Survey uiakiuo possiltle the poisouiug of Federal
lands within the districts and of a strip of tlie National
Forest immediately adjoining them on the west has greatly
enhanced the value of the work. In sevin-al instances it
has been possible to work back several nules into certain
canyons Avhich are particularly dangerous. AMiilc this
work has covered only a small part of the National Forest
it has, nevertheless, decreased migration from the foothills
to the valley.

CONTROL OF OTHER RODENTS

While the Cohunbian ground squirrel work has been the
main feature of rodent control, the control of other rodents
has only been neglected to the extent dictated by lack of
funds. Not only are land owners and residents advised to
kill all rodents possible, l)ut all men connected with the
work are required to do so, shooting or poisoning as the
case may be. The results accomplished in this way, how-
ever, leave much to be desired.

The importance of tlie control of other rodents becomes
accentuated in the canyons as they open into the moun-
tains. Here the preponderance of ground squirrels found
uud(^r valley conditions begins to give way to an increasing
proportion of other susceptible rodents, together with an
apparent increasing infection in the ticks. It has never
been possible to dircn-t adeijuate attention to these areas.

During the present season, wliile attempting to develoj)
new poisons for ground squirrels, one made by the simph^
addition of cracklings to the regular formula was found
very effective for woodchucks. These rodents scarcely touch
the usual poison distiibution for go])hers, and the u'-w form-
ula is tlie only woodcliuck poison we have used that is
satisfactory under the conditions pertaining to this area.
Snowshoe and cottontail rabbits take tlie regular poison
quite satisfactorily during the spring and summer, and all
poisoners are instructed ti» distri1)ute it in rabbit areas
whenever possible. Snowshoes can be more economically
combatted during the winter months, liowever, and exju'ri-
ments are being conducted in an attempt to develop a
satisfactory winter poison.

BOARD OF ENTOMOLOGY 25

POINTS IN WHICH THE RODENT CONTROL WORK IS

DEFICIENT AND RECOMMENDATIONS FOR

THEIR CORRECTION

Tlie changes in the control procedure made necessary dur-
ing the past two seasons have been outlined above and it
has been pointed out that the present plan is expected to
do little more than prevent conditions from going back-
ward. In some areas they should improve. Although this
restricted program was originally adopted as a temporary
measure because of financial conditions, it is now recom-
mended that it be continued pending the results of the in-
vestigation being carried on by the Federal Public Health
Service. A part of tliis investigation concerns the factors
which o])erate to ])('ri)('tuate Rocky Mountain spotted fever
under natural conditions. If it be possible to discover and
understand these factors, the control program can be
altered in such ways as may be necessary. The recom-
mendation for the continuance of the present plan, how-
ever, is made with the idea that every possible effort be
made to increase the efficiency of the rodent control and
in the following paragraphs the weak places are indicated
and certain suggestions made for their correction,

1. Columbian Ground Squirrel Control

One of the most disappointing features of the Colum-
bian ground squirrel work is the unsatisfactory degree of
control attainable under the present working conditions in
some of the most heavily infesttMl and most dangerous
areas. Under the most favorable circumstances this rodent
is difficult to control, but in the rough, mountainous
areas bordering the Bitter Root Valley, the problem is
especially troublesome, and all possible steps should be
taken to increase efficiency. The most potent factor oper-
ating against efficiency is a financial one, though it is per-
haps less a question of amount of funds than of the method
by which such funds are obtained and the limitations
placed by law on their expenditure.

The law previously referred to, under which the Avork is
now conducted, provides that the land owners, on whose
land work is performed by the State, shall pay the cost
of labor and material used, the cost per acre, however, not

26 FIFTH ANNUAL REPORT

to exceed five cents per treatment. The State, on the
other hand, must bear the cost of supervision, travel, auto
mileage, printing, clerical assistance and many miscella-
neous items. At the time of enactment it was expected that
this arrangement would be satisfactory, but four years'
experience has indicated certain defects: (1) The limita-
tion of the cost to five cents per acre is a serious handicap.
In many places conditions are such that real results can
only he secured at an expenditure considerably iu excess
of this amount. On suc]i areas, and unfortunately they
for the most part are fouud in the dangerous foothill
country, the work is necessarily far from being fully effec-
tive. (2) Many land owners attempt to do the necessary
work themselves to avoid labor charges. This is usually
unsatisfactory; the farmer rarely does thorough work and
can not be relied upon to poison his land at the same time
the areas adjoining his are Iteing treated. The inability
to secure results on the five-cent limit is sometimes Idue to
heavy infestation, sometimes to difficult country to work
in, and sometimes to the peculiaritiej? of the squirrels them-
selves. When infestation has been heavily reduced it is
often found that the remaining gophers are "poison-shy."'.
In such cases shooting and other methods are necessary
but are now prohibited by the acreage limit. (3) The law
requires that assessment records be in the office of the
county treasurer concerned on or before August 1st. This
is necessary in order that they may be placed on the assess-
ment lists. Because of this the field control must be
brought to a close during the first week in July in order
to get the records into shape, thus depriving us of one of
the best periods of the season for poisoning, namely, that
just prior to holing up for the Avinter. (4) It is now
necessary to keep our records on the basis of land owner-
ship. This is unfortunate because many of the records
would be extremely valuable if based on permanent units
of area such as sections, quarter sections, etc., whereas
the constantly sliifting of ownership boundaries prevents
this under the present system.

Since it is inadvisable to increase the limit of cost per
acre and since even if advisable this would only solve a
part of the difficulties, it is suggested that some other

BOARD OF ENTOMOLOGY 27

means of financing the work be sought other than a direct
tax on the land owners. It is tlierefore recommended that
the State, or the counties concerned, or both, assume the
major share of the Imrden of rodent control. The ineffi-
ciencies above noted will tluis be removed in part and the
results secured will then be dependent on the degree of in-
tensive work permitted by tlie funds available.

In this connection there is a question in the minds of
the writers as to just what part of the expense of rodent
control is justly chargeable against the land. The benefits
of the work are not confined to the west side of the Bitter
Eoot Valley, but directly or indirectly concern the entire
State. Furthermore, the situation with regard to the land
owner and Eocky Mountain spotted fever is peculiar, in
that the basic factor which permits the tick to exist is
animate, and not an inherent physical property of land.
Furthermore, this animate factor, Avild animal life, is
one which can only be very slightly affected by any
effort of the individual. The individual owner may combat
rodents and ticks on his own place with some success, per-
haps, but he can not well control rodent movements on to
or from his land, nor prevent the carrying of infected ticks
by such rodents, nor can any work which he may do affect
the amount of infection in the foothills and mountains, from
which there is reason to believe that the infection is con-
tinualh^ spreading to the valley.

Besides the financial question another factor which
affects the efficiencj' of the work is the matter of super-
vision. During the past two seasons the person in charge
has had but one deputy to assist him, whereas formerly
four was the smallest number employed. These men must
be supplied with poison, their records collected, their work
inspected and their camps moved as necessity requires.
Poison must also be distributed to ranchers and their work
inspected. Land on which the work has been inefficient
must be repoisoned (at present this can only be done by
men on State pay). Besides these duties in connection with
the ground squirrel work, the person in charge is respon-
sible for the filling of the vats and testing of solutions, the

28 FIFTH AXXFAL REPORT

enforcing of the quarantine anil other niiiscellaneous duties.
It is, of course, apparent that witli the control work oper-
ating over an area sixty miles long and in one place tliirty
miles wide, it is impossible for the person in charge, with
the aid of one deputy, to efficiently^ x^erform the necessary
work. The inspection of work performed necessarily suf-
fers since this is the one duty that it is possible to slight.
It is, liowever, very essential to good results. It is recoln-
mended that an additional deputy l)e appointed for a^ ])eriod
of four months, from April 1st to August 1st, and that
necessary funds be jirovided for Ids mileage. While this will
not provide the amount of supervision actually needed, it
will make it possible to station one deputy in each end of
the control area anil will be a material help.

2. Control of Other Rodents

As the control of the Coluuiibian ground squirrel makes
headway, the necessity for the control of other rodent
species is becoming more and more evident. It has been
pointed out in a previous section of this report that while
the control of the ground squirrel will accomplish more
toward tick control under valJei/ and footJilU conditions
than any other one method that it is now feasible to
employ, yet there are areas scattered throughout the in-
fected districts in which ground squirrels are absent or few
in number, and in these areas other rodent species sus-
ceptible to the fever are present, take the i)lace of the ground
squirrel. It is, therefore, evident that in these areas the
ground squirrel work only indinn-tly affects tlie abundaiu-e
of infecteil ticks. In the valley and foothills tliese areas are
largely occupied by woodchucks, snowshoe rabl)its, cotton-
tail rabbits, pine squirrels and chipmunks. It has further
been pointed out that in the portions of the mountain
canyons that adjoin the valley the ground squirr(d whicli
in the foothills and valley exceeds in abundance all othcn-
rodents combined (mice excluded), here gives way to tlieir
preponderance. Furthermore, the infection in these places
is very heavy and can not be greatly reduced by ground
squirrel control. Since tlie canyons are evidently avenues
for the valley areas, movement of tick-infested iDih'iits to

BOARD OF ENTOMOLOGY 29

valley areas, it is essential that all i)ossil)le effort be ex-
pended ill this direction.

While a considerable sum could easily be expended for
the control of these other rodents and the work continued
throufiliout the year, at the present time it is only asked
that an amount be provided sufficient to keep a crew of
three men in the field for a period of three montlis. It is
proposed to us^e such a crew in selected areas to follow
behind the prisoners, killing by shooting and trapping such
ground squirrels as are left and killing all possible rodents
of other species. This crew would be used for work in the
particularly dangerous localities.

VATS

There are within the control areas seven dii>i)iiig vats.
Nione of these is in good repair and three are unfit for use.
It has not been possible to spend sufficient money on their
upkeep since the Board took oxov the control work. They
are much used and it is very unfortunate that fuiiLS are
not available to keep them in proper condition.

Dr. S. B. Wolbach, who formerly contributed materially
to our knowledge of Rocky ^Mountain spotted fever has,
with his associates, recently made anotlier distinct and
valuable addition. These gentlemen have been able to
culture the organism of spotted fever and a copy of his
article (I'roceedings of the Society for Experimental Medi-
cine and Biology) follows:

THE CULTIVATION OF THE ORGANISMS OF ROCKY

MOUNTAIN SPOTTED FEVER AND TYPHUS

IN TISSUE CULTURES

S. B. WOLBACH, HENRY PINKERTON and MONROE J. SCHLESINGER
From the Departments of Pathology and Bacteriology,
Harvard Medical School

In these experiments tissues from infected auult guinea
pigs were grown in plasma obtained from normal guinea
pigs. With Kocky Mountain spotted fever the bits of tissue
were taken from the tunica of the testes. Witli typhus the
cerebrad cortex was used. Tlie plasma was obtained from

30 FIFTH ANNUAL REPORT

adult normal siiiiiica pii»-.s by centrifiiging- cliilled blood col-
lected in paraffined tubes.

Our results with spotted fever prove that the virus sur-
vives and multiplies in sucli cultures. Evidence of survival
of the virus was obtained by causing the disease in guinea
pigs by injecting the cultures intrapei'itoneally. Althouoh
the spotted fever reaction is very characteristic, the results
were controlled by histological studies or by subsequent
immunity tests.

Elvidence of multiplication of the virus was obtained by
demonstration of the minute paired micro-organism of the
disease (Dermaeentroxenus rickettsi) in increasing num-
bers in first general cultures up to about the fourteenth
day. The micro-organisms are always intra-cellular, in
large amoeboid phagocytic cells of endothelial origin.

The accompanying table show^s the duration of survival
of the micro-organisms in first ^'generation" cultures,
Experiments of iVugust 17, October 10 and October 24, and
the prolongation of this period by transplanting the cul-
tures into fresh plasma. Experiments of October 31 and
November 7.

The examination of cultures fixed in Zenker's fluid,
sectioned and stained with Giesmsa's stain, shows that the
period of survival of tlie micro-organisms corresponds to
the length of survival of the cells of tlie culture. Initial
multiplication of tlie micro organisms takes place in situ in
endothelial cells of blood vessels and continues in wander-
ing cells of the same origin.

In addition to the forms of the micro-organism previously
described, filamentous forms are occasionally found re-
sembling those of Rickettsia prowazeki as seen in infected
lice.

With typhus Ave have not completed experiments be^^ond
first "generation" cultures. Guinea pigs inoculated after
eight, eleven, and fourteen days incubation of tlie cultures
have acquired typhus, as was proved by typical tempera-
ture reaction plus characteristic lesions in the brain or
immunity.

Micro-organisms consistent with liickctf.sia iiroirazeJx-i
have been found in sections of the brain cultures within
large wandering amoeboid cells, but their demonstration

BOARD OF ENTOMOLOGY 31

is attended with the same difficulties m these tissue cul-
tures as in sections of fresh tissues with lesions. The ex-
amination of sections of the cultures shows that the sur-
viving cells in these brain cultures take origin in blood
vessels and meninges. Nerve cells and apparently neuroglia
cells do not sur\ ive. The wandering amoeboid cells, we be-
lieve, are of endothelial origin.

The well-known vagaries in duration of incubation periods
and intensity of temperature reactions of typhus in guinea
pigs render progress slow in these experiments. 0ur results
so far prove that the micro-organism of typhus survives in
first ^'generation" tissue cultures up to fourteen days.

These experiments with both diseases are being continued
and extended and in the case of typhus with other tissues
than those of the central nen'ous system.

Explanation of Table

The arrows indicate transfers of the tissue, or fragments
thereof into fresh plasma.

+ Indicates a typical reaction followed by immunity to
subsequent inoculation with spotted fever blood.

Guinea pigs C22, C23, C27 were killed.

Guinea pigs C26, C28, C30, C34 and C43 succumbed to
the infection.

Guinea pigs C35, C36, C38, 042, C45 and C47 survived
the infection.

32

FIFTH ANNUAL REPORT

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