Montana insect pests for ... being the ... report of the State Entomologist of Montana

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353.9

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1949 NO. 32

1

BULLETIN 457

JANUARY, 1949

Montana Insects Pests
1947 and 1948

Thirty-Second Report

of the

State Entomologist

MONTANA STATE COLLEGE QQ J Q

AGRICULTURAL EXPERIMENT STATION
BOZEMAN. MONTANA

SUTE

MONTANA

1515 E.
HELENA, MONTANA

STATE PUBLICATIONS COLLECTION

12007

LIBRARY
>th AVE.

59620

Bozeman, Montana

To His Excellency
Governor John W. Bonner
State House
Helena, Montana

My Dear Sir:

I am submitting herewith the Thirty-second
Report of the State Entomologist of Montana. This
report contains information concerning insect control
programs, the status of the more important and
unusual insects, and newly introduced pests.

Demands on this office have greatly increased
during the last biennium. Insect control has become
larger in scope and it has been necessary to organize
and direct new programs. During the last biennium
the State Entomologist's office conducted 35 educa-
tional meetings with a total attendance of 1,391
persons; 7 demonstrations were given with an attend-
ance of 75 persons; 184 field contacts were made; 837
inquiries concerning insect identification and control
were answered; and 12 publications and newsletters
were issued.

The demands for demonstrational and educational
work have become so heavy that additional personnel
will be required if these demands are to be met. Unless
the State Entomologist appropriation is increased to
take care of these additional activities, some important
phases of the State Entomologist's programs will have
to be curtailed.

Respectfully submitted.
James H. Pepper
State Entomologist

Montana Slate Library

3 0864

1004 0574 8

MONTANA INSECT PESTS
1947 and 1948

THIRTY-SECOND REPORT OF THE STATE ENTOMOLOGIST

J. H. Pepper, O. B. Hitchcock, C. R. Hunt,

Ralph Schmiedeskamp1

INTRODUCTION

The entomological outlook for Montana presents a number of
ramifications which have not been previously stressed. Our insect
problems have increased in the last decade and the possibility of
further serious situations arising is almost certain.

During the last few years, we have had infestations of a number
of insects new to the state. Likewise, some native insects that have
not previously been pests have caused considerable damage to
agricultural crops. It had been predicted by earlier workers that
two of these new insects, the alfalfa weevil and the differential
grasshopper, could not become established in Montana because of
our ecological conditions. At the present time both of these insects
have become serious pests. The differential grasshopper was first
found in Dawson County in 1932. Since that time it has spread over
much of the eastern and southern parts of Montana and is now
found in economically important numbers as far west as Yellow-
stone and Big Horn counties. The alfalfa weevil was first observed
in 1938 and has been a serious pest to alfalfa in Southeastern
Montana since 1945. It has spread every year and at the present
time it is as far north and east as Terry and as far west as Reed
Point. This pest has become so serious in some sections that it has
threatened the alfalfa seed and feed growing industries.

It was assumed by many of the early workers that climatic
factors were primarily responsible for limiting the distribution of
many of these pests. It is apparent from the above examples that
the ability of an insect to adapt itself cannot be overlooked in
predicting the limits of its geographic distribution.

The wheat stem sawfly, which is a native insect of Montana,
did not become important economically until 1941. Since that time
this insect has become one of our most serious pests of spring and
winter wheat, at present confining itself largely to the northern
part of the state.

Changes in our agricultural crops and farm practices have
resulted in bringing about conditions which are more favorable to
some insects. It is interesting to note that the spread of the wheat

'Stat<- Entomologist. Assistant State Entomologist, Montana Agricultural Experiment
Station Entomologist, Assistant State Apiarist, respectively.

4 MONTANA EXPERIMENT STATION BULLETIN 457

stem sawfly and increased losses caused by this insect paralleled
the development of the practice of strip farming. It is now known
that this practice produces the optimum conditions for sawfly
activities. In the case of other pests, the reasons for their increased
activities are not so apparent but are in all probability related to
the increase in production of certain favorable host plants or the
adoption of certain cultural practices which may favor their
development.

The complications which may arise from the indiscriminate
use of new organic insecticides should not be overlooked. In many
cases these new materials are extremely toxic to all animal life and
are being used so that beneficial insects such as parasites, predators,
and pollinators are being almost completely eliminated from
treated areas. The results of this usage may complicate our problems
greatly; however, it is too early to tell how this may effect our
whole insect complex. Already there are indications that serious
situations may arise from the promiscuous use of these materials.
A great deal of research and study will be necessary to properly
evaluate the above situation.

It is difficult to tell whether or not livestock pests are becoming
more serious or whether the increased interest is because farmers
and ranchers are becoming insect-conscious. It is obvious that
stock-growers are becoming increasingly aware of the losses caused
by insect parasites, and are requesting information and demon-
strational programs to acquaint them with the insects involved and
the methods for controlling them.

With the development of new insecticides that are effective
in controlling mosquitoes, there has been a marked increase in
attempts to eliminate these pests in and around urban areas. Many
towns throughout the state have organized control programs, some
of which have been very successful in eliminating mosquitoes as
well as flies. Other programs have not been so successful because
they were not correctly planned or correctly executed. Increased
emphasis on educational programs, demonstrations, etc., will go
a long way in remedying the above situations.

HARMFUL AND DESTRUCTIVE INSECTS

INSECTS INJURIOUS TO CROPS IN GENERAL

GRASSHOPPER CONTROL

1947 SEASON

Since 1942, when grasshopper populations were the lowest
they had been in several years, there has been a gradual and
general increase in grasshopper numbers. The infestation in 1947

MONTANA INSECT PESTS, 1947 AND 1948 5

was more severe than that of the previous year. Their appearance
was late because of cold, rainy weather in May and June, which
retarded the development and hatch of the eggs. Because of these
weather conditions, the hatch was extremely irregular and it
extended over a period of approximately three months. One of the
most severely infested areas was in the Big Horn, Yellowstone,
Treasure, Rosebud, Custer, Powder River, Prairie, Dawson and
Richland counties, with heaviest populations occurring along the
Yellowstone River and its tributaries. The most heavily infested
localized area in the state included eastern Glacier,' southern
Toole, and northern Pondera counties. Small spotted infestations
of a more localized nature were also found in sections of the
northern and central parts of the state. The dominant species in
the northern part of the state were Melanoplus bivittatus,
Melanoplus packardii, and Camnula pellucida. The build-up of the
latter species was quite pronounced in limited areas within the
above region. In the eastern part of the state the dominant species
were Melanoplus bivittatus, Melanoplus differentialis, and Melano-
plus jemur-rubrum. The 1947 infestation was characterized by the
continued build-up of M. bivittatus and M. differentialis and an
apparent decline of M. mexicanus, which had been the dominant
species for many years. The damage caused to crops by these
insects was relativelv light considering the heavy populations
which were present. This was due largely to the fact that barrow
pits, fence rows, rights of ways, and other marginal areas main-
tained a heavy succulent growth of weeds which remained green
during most of the season. Heavy migrations from these areas
were not observed until the harvesting of most crops was well
under way. Some damage did occur to new growths of winter
wheat in the late fall.

The weather during the egg laying season was favorable for
egg deposition; consequently, heavy egg deposits were found in the
infested areas. Western Glacier County had one of the heaviest
egg populations that has ever been recorded in the state. In many
sections fifty egg pods per square foot was not an uncommon
count.

1948 SEASON

The grasshopper infestation of 1948 was more severe than any
of those occurring during the previous five years. The areas
infested were in the same regions as in the previous year but were
more extensive. In addition, heavy populations were also present
in the Judith Basin area. In general, heavier populations were
likewise found in the northern part of the state. The dominant
species in the above areas were M. bivittatus, M. differentialis,
and M. packardii. In the late summer extremely heavy grasshopper
populations developed in the range areas in the eastern part of the

6 MONTANA EXPERIMENT STATION BULLETIN 457

state. Heavy damage was caused to the range, in some instances
necessitating the disposal or movement of cattle from these badly
infested ranges. An adult survey of the range populations showed
that 32 species of grasshoppers were present. The following is a
list of species and the percentage in which they occurred :

29.8 Melanoplus mexicanus (Saussure)

18.9 Phoetalictea nebrascennis (Thomas)
18.0 Ageneotettix deorum (Scudder)

6.9 Drepanoterna femoratum (Scudder)
2.7 Opeia obscura (Thomas)

2.6 Melanoplus keelari (Thomas)

2.3 Melanoplus femur-rubrum (DeGeer)

2.2 Philbostroma quadrimaculatum (Thomas)

2.1 Trachyrpachis kiowa (Thomas)
1.9 Encoptolophus costalia (Scudder)

1.7 Hesperotettix viridis (Thomas)

1.3 Melanoplus packardii (Scudder)

1.2 Spharagemon sp.

1.0 Amphitornus coloradus (Thomas)

1.0 Arphia sp. Arphia

1.0 Aulocera elliotti (Scudder)

1.0 Melanoplus dawsoni (Scudder)

.8 Hypochlora alba (Dodge)

.7 Hadrotettix trifasciatus (Say)

.7 Melanoplus gladstoni (Scudder)

.5 Melanoplus bivittatus (Say)

.3 Melanoplus infantilis (Scudder)

.3 Mermiria maculimennis (Bruner)

.3 Metator pardalinus (Saussure)

.2 Melanoplus bowditchi (Scudder)

.2 Melanoplus differential (Thomas)

.1 Melanoplus angustipennis (Dodge)

.05 Acrolophitus hirtipas (Say)

.05 Aecloplus turnbulli (Thomas)

.05 Boonedon nubilum (Say)

.05 Dissosteira Carolina (Linneaus)

.05 Trimerotropis sp.

It is of interest to note that 29.8 percent of the hoppers col-
lected were Melanoplus mexicanus. The heavy build-up of this
species seems particularly significant because it has not been the

MONTANA INSECT PESTS, 1947 AND 1948 7

dominant species in this area for several years. Some flights of
M. mexicanus were observed in the eastern part of the state and
a heavy flight was reported to have moved into Northern Montana.
As in 1947, the grasshopper damage to crops was relatively light in
1948 because of the succulent marginal growth. In some cases, even
though heavy populations of M. bivittatus and M. packardii were
observed in grain fields, the actual damage to these fields was
slight. Some damage did occur, however, due to leaf and head
feeding. The above species do not cut the heads and cause the
severe destruction that occurs when M. mexicanus are present.

Large amounts of organic insecticides were used in grass-
hopper control — the most common of which were Toxaphene and
Chlordane. These materials gave excellent control when used as
sprays or dusts in succulent foliage. They serve to replace baits
which are generally ineffective under these conditions.

In scattered localized areas, hopper populations were greatly
reduced by scarcophagid flies. Fungus and bacterial disease were
also responsible for slight reductions in grasshopper populations
in alfalfa and mustard fields. Unfortunately, these parasites did
not occur over large enough areas to be of great significance.

THE OUTLOOK FOR 1949

The 1948 fall surveys of adult and egg populations indicate
that the grasshopper infestation for the coming season may be one
of the most severe since the 1939-40 outbreak. As was previously
pointed out, all of the infested areas have increased in size and
heavy populations have developed in many new areas. This is
especially true in the northern and central part of the state. The
heavy build-up of M. mexicanus and the apparent spread of this
species from the eastern part of the state as well as from other
areas, indicates that it may soon be the dominant species in Mon-
tana. If this infestation does occur, increased crop losses are
imminent.

OTHER IMPORTANT PESTS

WIREWORMS (Elateridae)

During the last biennium the damage from wireworm activi-
ties has increased considerably. Their presence was confined to
limited areas spotted throughout Montana. In the eastern two-
thirds of the state most of the wireworm damage occurred in small
grains. In the western third, damage commonly occurred in pota-
toes and sugar beets. During the last season, wireworm damage to-
sugar beets was considerably heavier than in previous years.

GARDEN SLUGS (Agriolimax agrestis)
During the 1948 season, garden slugs were a major pest in the

8 MONTANA EXPERIMENT STATION BULLETIN 457

western half of the state. They caused severe damage to garden
crops, especially potatoes, lettuce, cabbage, and strawberries. This
build-up was apparently due to the high amount of rainfall which
occurred during the growing season.

BLISTER BEETLES (Meloidae)

The eastern part of Montana had a severe infestation of blister
beetles in 1948. Most of the damage occurred to alfalfa and garden
crops. In limited areas throughout the state large numbers of
blister beetle larvae were found feeding on grasshopper eggs.
In some instances as high as 60 percent of the egg pods were
destroyed.

FLEA BEETLES (Epitrix spp.)

Flea beetles have a state-wide distribution. During the last
two years these insects have caused considerable damage to garden
crops. In some sections, spotted throughout the state, flea beetle
infestations almost completely destroyed garden plantings of cab-
bage, cauliflower, broccoli, radishes, beets, and turnips. In the
western part of the state, they were also recorded doing damage
to sugar beets.

WHITE GRUBS (Phyllophaga spp.)

White grubs caused some damage to new strawberry plantings
in the Bitterroot Valley during the last biennium. This damage
was especially noticeable where strawberries were set out on land
that was previously in sod. These insects were observed doing some
damage to flower gardens in the vicinity of Billings. In all cases,
the infestations were of a localized nature. It appears that white
grubs are becoming more common throughout the state.

MORMON CRICKETS (Anabrus simplex)

Mormon crickets have not occurred in outbreak numbers in
the state since 1941. There was a noticeable increase in the num-
bers of this insect in 1947 and an even greater increase in 1948.
It is possible to find a few mormon crickets in almost every
locality in the state.

At present these crickets seem to be scattered, as no bands
have been observed. From the observations that have been made,
however, it appears that a mormon cricket outbreak within the
next one to three years is likely.

EAR WIGS (Forficula auricularia)

During the last two years an ear wig infestation has appeared
over much of the western half of the state. These insects are gen-

MONTANA INSECT PESTS, 1947 AND 1948 9

erally nocturnal; coming out at night to attack many kinds of
plants including flowers, ornamentals, fruit trees, vegetables,
grains and grasses. They also enter houses to become a nuisance.
Although they apparently do not damage household materials,
their presence is extremely annoying. They seem to prefer dark,
moist habitats such as may be found around kitchen sinks and in
bathrooms; however, their activities are not confined to these
places. Since the first report of ear wigs occurring at Thompson
Falls in 1938, this pest has spread rapidly over a large part of the
state.

INSECTS INJURIOUS TO FIELD CROPS
SMALL GRAINS

WHEAT STEM SAWFLY (Cephus ductus)

The wheat stem sawfly continues to be one of the most serious
insect pests of wheat in Montana. All counties east of the moun-
tains are now known to be infested. Economic losses, however,
have been confined to Glacier, Pondera and Teton counties on the
west, and the adjoining northern tier of counties east to the North
Dakota line. McCone, Richland, Dawson, Wibaux, and Fallon
counties in the eastern part of the state have likewise been subject
to economic losses. An isolated area where sawflies are present also
exists in northern Fergus and Judith Basin counties in the vicinity
of Garneill. The most severe damage has been to spring wheat,
except in Glacier, Toole, Pondera, and Teton counties where
winter wheat losses have been severe.

The areas where sawfly populations of economic importance
are found have increased considerably from the localities origi-
nally recorded. Just how this extension of infested areas is occur-
ring and how far it will go are questions that remain unanswered.
An extension of the infested winter wheat area seems to be in
progress and this presents a potentially dangerous situation.

Control of the sawfly is still based upon crop rotation and the
use of resistant crops and varieties. Compana barley and Rescue
wheat, a resistant variety, have been planted with excellent results
in hundreds of thousands of acres where sawfly damage was
severe. The original two bushels of Rescue wheat obtained in 1944
from Canadian workers was increased to 1,250,000 bushels by the
fall of 1947, to furnish a sufficient supply of seed for seeding all
seriously infested acreage in 1948. An appreciable amount of the
1948 crop of Rescue wheat was directed into commercial channels.

Just what effect the extensive use of Rescue wheat will have
on the overall problem remains to be seen. Where Compana barley
and Rescue wheat have been planted on individual farm units,
significant sawfly population reductions based on reduced damage,

JO MONTANA EXPERIMENT STATION BULLETIN 457

have been observed. In the extreme northeastern counties, late
seeding plus extensive use of Rescue wheat, have resulted in very
decided reductions in sawfly population. In the western area
where Rescue wheat was used, populations were greatly reduced
in spring wheat, but the amount of infested winter wheat will
probably equalize any general reduction in population resulting
from the increased Rescue wheat acreages.

The performance of Rescue wheat is as yet a debatable ques-
tion. In the northeastern counties it appeared to yield significantly
less than Thatcher, when sawfly damage was not a factor. In addi-
tion, it appeared to be less drouth hardy, and more susceptible to
lodging. In the western area, yields were excellent and lodging
was on the same level with other standard varieties. Some discus-
sion was heard regarding combining difficulties, both in handling
the straw and knocking out the kernels. On the other hand, claims
were made that it shattered easily. From these widely divergent
opinions, it would seem that more experience with Rescue wheat
is needed before it can be best evaluated. It is then very probable
that it will be found better suited to some areas than others.

Milling and baking tests have shown Rescue wheat to be a
satisfactory bread wheat. When used alone it has about 3 percent
less water absorption than does Thatcher, a rather important
criticism from the standpoint of the millers and bakers. In other
milling characteristics it is equal to Thatcher and there are indica-
tions that proper blending will reduce the absorption difficulties.
Most of these tests have been conducted by the Northwest Crop
Improvement Association and cooperating cereal laboratories.

The problem of controlling the sawfly in winter wheat is made
more difficult by the lack of any resistant winter wheat varieties.
A breeding program has been initiated by the Department of
Agronomy and Soils at Montana State College which is attempting
to breed some of the resistance from Rescue wheat into our better
winter wheat varieties. A program has also been started as a
cooperative effort of the Department of Zoology and Entomology
and the Department of Agronomy and Soils of Montana State
College together with the United States Bureau of Entomology
and Plant Quarantine and the Bureau of Plant Industry, Soils and
Agricultural Engineering to test 2,000 foreign wheat introductions
for new sources of sawfly resistance.

ARMY CUTWORMS (Chorizagrotis auxiliaris)

These cutworms, although not a serious problem during the
last biennium, caused some damage in small areas in the eastern
two-thirds of the state. They were observed feeding on small

MONTANA INSECT PESTS, 1947 AND 1948 11

grains in this area. Another cutworm species was reported to have
damaged the terminal buds of sour cheery plantings in the Bitter-
root Valley.

PALE WESTERN CUTWORMS (Agrotis orthogonia)

Pale western cutworm damage was observed in the vicinity
of Great Falls and Havre during 1947 and 1948. The infestations
were small and occurred in localized areas. Heavy flights of pale
western cutworm moths were observed in the north-central part
of the state during the fall of 1948.

The practice of trash fallowing in the above area may produce
conditions more favorable for egg deposition by the adult moths.
Since the moths select uncrusted soil in which to lay their eggs,
the action of the wind on the trash present in this type of fallow
may prevent the formation of a crust adjacent to the exposed
stems, thus increasing the areas within a field which are suitable
for egg laying. This may be another instance where cultural prac-
tices are at least in part responsible for producing conditions which
are favorable for the spread of an insect during the outbreak
years. Further investigations are necessary to determine the exact
effect of these practices on the relationship which exists between
this insect and the condition of the fallow.

HESSIAN FLY (Phytophaga destructor)
The Hessian fly occurs in the northern and eastern parts of
Montana. In 1924 and again in 1944 this insect caused considerable
damage to wheat in these areas. During the last two years, hessian
flies have been observed in small numbers but sufficient popula-
tions have not developed to make this pest of any great economic
importance.

WHEAT STEM MAGGOT

During the 1948 season, the stem maggot has been observed
occurring in large numbers over the state. It has been especially
noticeable in Big Horn, Yellowstone, and Cascade counties. While
it has caused some damage to wheat, it has been more destructive
to crested wheat grass in these counties. To date actual determina-
tion of the species involved has not been made.

CORN

CORN EAR WORM (Heliothis armigera)
No report of the corn ear worm having caused damage in 1947
was received. In 1948 a field of sweet corn near Park City was
observed to have a corn ear worm infestation. Approximately
30-40 percent of the ears were damaged. No other infestations were
reported or observed in the state.

12 MONTANA EXPERIMENT STATION BULLETIN 457

SEED CORN MAGGOT (Hylemya cilicrura)

Some damage to bean fields, caused by the seed corn maggot,
was observed in the Billings area in the spring of 1947, and in the
Bitterroot Valley a small acreage of beans was severely damaged.
No damage was reported in 1948.

BUMBLE FLOWER BEETLE (Euphoria inda)

Specimens of the bumble flower beetle were received from the
Billings area in September of 1948. It was reported that the ears
in a field of mature corn were being damaged by this insect. This
pest was previously recorded occurring in the same area in Mon-
tana in 1911, 1912, 1915, and 1916. In all of these cases it was found
to be damaging corn. The bumble flower beetle has apparently
never occurred in large enough numbers to be of particular eco-
nomic importance. It has not been recorded as occurring in any
other section of the state.

ALFALFA

ALFALFA WEEVIL (Hypera postica)

Since the first outbreak of alfalfa weevil in southeastern
Montana in 1946, this insect has continued to be one of our most
serious pests of feed and seed alfalfa. The infested area has
increased from year to year until, at the present time, the infesta-
tion extends over the southeastern section of the state from Terry
to Reed Point. The alfalfa weevil has become so serious a pest that
many farmers have discontinued the growing of alfalfa. Since this
insect has been able to establish itself in the state and has con-
tinued to spread, it appears likely that a further spread may be
expected. The State Entomologist's office and the Montana Agri-
cultural Experiment Station have carried on considerable research
in an effort to develop more satisfactory control measures. From
the results of this work, a more satisfactory control method has
been developed.

LYGUS BUGS (Lygus sp.)

Lygus bugs are found in all sections of the state and are pests
in many areas where alfalfa and clover seed are grown. In 1947
heavy populations of lygus bugs were observed causing damage to
alfalfa along Pryor Creek, south of Billings. Alfalfa fields from
which hay crops have been removed each year for a period of
years, generally have a lighter lygus infestation than fields which
are left for seed. This may account for some of the fluctuations
in numbers.

MONTANA INSECT PESTS, 1947 AND 1948 13

ALFALFA SEED CHALCID (Bruchophagus funebris)

This insect is distributed over the entire clover and alfalfa
seed-producing areas of Montana where it is found to damage seed
production of these crops. Samples of seed obtained in 1947 from
the Camas Prairie section showed chalcid damage to aporoxi-
mately 40 percent of the seeds. It has also been a serious pest of
clover seed in the vicinity of Charlo.

PEA APHIS (Illinoia pisi)

The 1948 season showed higher populations of pea aphis in both
alfalfa and clover in western Montana than were present in 1947.
In some fields, populations were severe enough to necessitate the
application of control measures.

POTATOES

COLORADO POTATO BEETLE (Leptinotarsa decemlineata)

The Colorado potato beetle was observed damaging potato
fields in the vicinity of Kalispell in 1947 and around Great Falls
in 1948. In both cases the infestation was severe enough to necessi-
tate a control program over much of the potato acreage. Some
damage to potatoes has been noted in the Bitterroot Valley during
the last two years.

POTATO PSYLLID {Paratrioza cockerelli)

On occasion the potato psyllid has been a serious pest in the
eastern part of the state. Surveys to determine its presence have
been conducted for the last two years throughout the potato grow-
ing areas of eastern Montana during the month of June. No adult
psyllids were found in the areas surveyed in either 1947 or 1948.
These areas were determined by previous investigations to be
the areas most likely to give an indication of general psyllid
populations.

SUGAPt BEETS

SUGAR BEET WEBWORM (Loxostege sticticalis)

In 1947 sugar beet webworms appeared in economic numbers
in Cascade and Teton counties and in Ravalli, Missoula, and Lake
counties. Heavy moth flights were observed in the spring of 1948
from Billings west to the Bitterroot and north to the Chinook-
Choteau area. Infestations of the webworm were spotted through-
out this entire region. Populations as high as 25-30 worms per
plant could be found on sugar beet plants and other hosts. Con-
siderable control work was carried on throughout the infested
areas.

14 MONTANA EXPERIMENT STATION BULLETIN 457

In the Bitterroot and Gallatin valleys a heavy second genera-
tion moth flight was observed. However, no second generation
larvae were reported.

SPINACH LEAF MINER (Pegomya hyoscyami)

This insect may be found wherever sugar beets are grown in
Montana but generally it is of little economic importance. How-
ever, it caused some damage to sugar beet fields in the vicinity of
Great Falls and Conrad in 1948.

SUGAR BEET ROOT MAGGOT (Tetanops aldrichi)

In the western Montana sugar beet growing area, the sugar
beet root maggot causes light damage every year. In the Bitterroot
Valley, considerable damage occurred in 1948. Some fields were
abandoned because of the heavy infestation. It seems that the
populations of this insect have been increasing for the last five
years. The poor growing conditions prevailing during the early
part of 1948 probably contributed to the damage caused by this
insect by lessening the plants ability to recover.

PEAS

PEA WEEVIL (Bruchus pisorum)

The first mention of this pest having been introduced into
Montana was in 1912, at which time it was found in seed shipped
into the Gallatin Valley. Its occurrence in economically important
numbers has been periodic throughout the years from 1912 to the
present time. It has been found in the Yellowstone and the Clarks
Fork valleys in south-central Montana and in the western part of
the state. In general, the populations of the pea weevil in the
Bitterroot Valley were lighter in 1947 than in 1948. In some areas
of south-central Montana and western Montana populations were
sufficiently high to necessitate control measures in both 1947 and
1948. To what extent this insect has been able to overwinter under
Montana conditions has not yet been established.

INSECTS INJURIOUS TO GARDEN AND TRUCK CROPS

CRUCIFERA

CABBAGE MAGGOT (Hylemya brassicae)

The cabbage maggot is distributed throughout Montana and
its activities generally result in some damage every year. This
insect attacks the roots of all cruciferous plants. No severe out-
breaks have been reported in the last two years. However, in years
previous to these this pest has been recorded as causing damage in
the Bitterroot Valley.

MONTANA INSECT PESTS, 1947 AND 1948 15

IMPORTED CABBAGE WORM (Pieris rapae)

This is one of the more common pests of cruciferae in the state
of Montana. In some sections, it has become impossible to grow
these crops in gardens unless stringent control practices are carried
out. Generally, attacks of this pest are associated to some extent
with the cabbage looker (Autographa brassicae) , and the diamond
back moth (Plutella maculipennis) .

CABBAGE APHIS (Brevicoryne brassicae)

As was the case with most aphis species, the cabbage aphis
was more prevalent in 1948 than in 1947. It is a state-wide pest
which will attack cabbage, cauliflower, turnips, etc., commonly
planted in the home garden.

ROOT CROPS

ONION MAGGOT (Hylemya antiqua)

Present distribution records indicate that this insect is present
over most of Montana. During 1948 most of the damage occurred
in the western portion of the state with one grower near Hamilton
reporting an approximate 20 percent loss of onions due to the
presence of this pest.

ASPARAGUS

ASPARAGUS BEETLE (Crioceris asparagi)

In 1948 this pest was found on Findley Point, Flathead Lake,
which is about ten miles from the point where it was first dis-
covered in the spring of 1946. It has now been observed to be
present from the south shore of Flathead Lake to Findley Point.
During the last two years, damage has occurred late in the season
after the plants have gone to seed.

INSECTS INJURIOUS TO FRUIT CROPS

APPLES

CODLING MOTH (Carpocapsa pomonella)

The codling moth is found in varying numbers wherever
apples are grown in Montana, with heavy infestations often occur-
ring in the Bitterroot Valley and in the Clarks Park Valley in
Carbon County. In 1947 the populations of codling moths were at
a low level in western Montana as a consequence of the very light
apple crop of the previous year. The numbers of codling moths
were higher in 1948 than in 1947.

16 MONTANA EXPERIMENT STATION BULLETIN 457

OYSTER SHELL SCALE (Lepidosaphes ulmi)

Oyster shell scale is present in all fruit-growing areas of the
state. In addition to attacking fruit trees, it often attacks shade
trees and ornamental plantings. It may become a serious problem
where home and commercial orchardists do not apply proper
insecticidal sprays.

WOOLY APPLE APHIS (Eriosoma lanigerum)

During the last two years, there has been an increase in wooly
aphis populations in apple orchards where D.D.T. has been used
for codling moth control. This increase is thought to be due largely
to a reduction of aphis predators brought about by the action of
D.D.T.

APPLE APHID (Aphis pomi)

This is a common pest thoughout the apple-growing regions
of Montana. During the last biennium, infestations have been
rather constantly becoming a problem in unsprayed orchards.

ROSY APPLE APHIS (Anur aphis roseus)
Wherever apples are grown in this state, the rosy apple aphis is
commonly encountered. During the last two years, the population
levels of this insect have apparently remained static. A spray
program appears necessary to prevent damage.

EYE-SPOTTED BUD MOTH (Spilonota ocellana)
As far as is known, this pest, which feeds on the buds and
blossoms of apples, cherries, and plums, is widely distributed over
western Montana. The populations of this insect have increased
to such an extent that they are now becoming of economic
importance.

CHERRIES

BLACK CHERRY APHIS (Myzus cerasi)
This is one of the principal cherry pests of the Flathead area.
Infestations of this aphis have been severe enough during the past
two years to necessitate the application of control measures.

CHERRY FRUIT FLY (Rhagoletis cingulata)
At the present time, this pest is known to occur in sour
cherries in certain districts of the Flathead area. In 1947, unsprayed
sour cherry trees were found to have 5 to 10 percent wormy fruit.
As yet, little is known about the adult fly, its activities, or its
distribution.

MONTANA INSECT PESTS, 1947 AND 1948 17

YELLOW JACKETS (Vespidae)

Various species of Vespidae are minor pests in the Flathead
and other areas in the western part of Montana. Some damage
occurs to the ripe fruit each year due to the feeding activities of
the yellow jackets. Equally important is the nuisance value they
have during the picking season.

PEAR SLUG (Caliroa cerasi)

The pear slug is widely distributed throughout the state and
is not confined to a single host. Severe defoliation may occur on
plums, pears, quince, hawthorne, Juneberry, etc. In general, there
are two broods a year, the first appearing in June and the second
in August. The second brood usually causes the most damage. In
1948, the slug populations did not build up early in the season
because of a high mortality, presumably induced by the cool, wet
weather which prevailed during June and July.

RUST MITE (Phyllocoptes sp.)

A 1947 survey of sweet and sour cherry trees in western Mon-
tana showed that nearly all plantings were heavily infested with
a species of rust mite. This was the first authentic record of the
rust mite damaging fruit trees in Montana. However, from all
indications, this pest has been present for several years but has
been overlooked. The trees that are heavily infested have the
general appearance of trees suffering from drouth. The leaves
become curled longitudinally and show a bronzed discoloration.
Sour cherry leaves generally show a more pronounced bronzing
than do the sweet cherry leaves. Preliminary life history observa-
tions indicate that this pest overwinters as an adult, hidden behind
leaf bud scales and in cracks in the bark near the terminal and
lateral buds. In the spring, feeding activity begins as soon as the
buds show green. Generally, population levels are low throughout
the early growing season and a build-up does not occur until the
advent of hot, dry weather. In 1947 this build-up occurred early in
July whereas in 1948 populations did not build up until late
August.

RASPBERRIES

RASPBERRY CROWN BORER (Bembecia marginata)

A preliminary survey of raspberry plantings in western Mon-
tana shows the crown borer to be present throughout the Bitter-
root and Flathead Valleys. In general, infestations are heavy in
many of the older plantings throughout both areas. Where vigorous
plantings are maintained, a loss of canes has not been severe,
however, in areas where the growth is less hardy due to soil

18 MONTANA EXPERIMENT STATION BULLETIN 457

fertility or other factors, some loss of canes has occurred in both
1947 and 1948. In 1948, the first adult activity was noted on
August 2nd.

RASPBERRY FRUIT WORM (Bijturus unicolor)

This insect pest is found in varying numbers throughout the
state wherever respberries are grown. During the 1947 and 1948
seasons, damage by this insect was in general, slight. In the Bitter-
root sections, a spray application is frequently employed as a
precautionary measure.

RASPBERRY SAWFLY (Blennocampa rubi)

The raspberry sawfly, although usually present where rasp-
berries are grown in the Bitterroot and Flathead valleys, is of
minor economic importance in these areas. In 1948, infestations
were more severe than in 1947.

PRUNES AND PLUMS

PLUM GOUGER (Anthonomus scutellaris)

The plum gouger was reported from the Billings area in 1948.
It has been recorded in past years, over most of the state where
plums are grown either as a commercial crop or for home use. In
general, it has been of little economic importance during the past
two years.

PLUM APHIS (Aphididae)

Damage from the plum aphis in sections of the Bitterroot was
more severe in 1948 than in previous years. Light to moderate
infestations occurred along the shores of Flathead Lake. Varietal
studies on plantings in the Bitterroot Valley indicate that some
varieties of plums, such as the Fiebing, are very susceptible to
plum aphis infestations, whereas Superior and other varieties are
moderately resistant.

STRAWBERRIES

STRAWBERRY CROWN MINER (Aristotelia jragariae)

An infestation of this insect pest was recorded from the
Bitterroot Valley in 1948, where it was doing considerable damage
to plots of experimental strawberry varieties. Available informa-
tion indicates that this pest had been present for at least six years.
At this time nothing more is known about its distribution through-
out the state, except that it was reported from Lake County in 1944.

MONTANA INSECT PESTS, 1947 AND 1948 19

CURRANTS

CURRANT APHIS (Capitophorus ribis)

In general, damage from this species of aphis has been light
during the past two years.

CURRANT FRUIT FLY (Epochra canadensis)

This insect pest is widely distributed throughout Montana. In
general, infestations were light for both years of the biennium.

INSECTS INJURIOUS TO SHADE TREES AND SHRUBS

EVERGREENS

SPRUCE GALL APHID (Adelges cooleyi)

The spruce gall aphid has continued to be quite prevalent over
the entire state during the last two years. It has caused consider-
able damage to ornamental spruce trees. It is a difficult pest to
control due to the variations in the dates of appearance of the
cottony stage. It is only in this stage that control methods are
effective.

PINE LEAF SCALE (Chionaspis pinifoliae)

Infestations of the pine leaf scale in varying degrees of
severity have been observed on ornamental pine trees throughout
the southern and western parts of the state. This insect is
apparently found all over Montana and has been especially notice-
able during the last biennium.

PINE BARK APHID (Chermes pinicorticis)

This pest was recorded from Corvallis in 1947. As yet, its
distribution in Montana is not known. The presence of this aphid
is indicated by spots and patches of white cottony material on the
smooth bark of the trunk and on the under sides of the limbs of
white pine. The white waxy threads are also seen at the base of
the needles, especially at the ends of branches. Attacks by this
insect weaken the tree, making it less resistant to the attacks of
other insects and of fungus diseases.

RED CEDAR APHID (Cinara sp.)

In the Bitterroot Valley, Juniper has been found seriously
infested with the red cedar aphid. Where these insects are present
usually the damage has been severe, characterized by the killing
of the needles to such an extent that the plant dies. The injury
produced is similar to that resulting from winter injury or red
spider damage.

20 MONTANA EXPERIMENT STATION BULLETIN 457

ASH

GREEN ASH APHIS (Prociphilus venafuscus)

In the vicinity of Hamikon, green ash is severely infested
every year by this aphis species. To date, it has not been reported
from other areas of the state. The principal damage occurs to the
leaves on which the aphis feed in the spring and early summer.
Their activities result in curling of the leaves and reducing
terminal growth. This insect overwinters in the egg stage in cracks
in the bark and trunk and on the main laterals of the ash tree. As
soon as the buds begin to swell, the aphis eggs hatch and the
young migrate to the leaf buds and commence feeding. During
June and July, winged forms appear which migrate to an alternate
host, returning again to the ash in September and October. These
winged adults produce wingless forms which ultimately produce
the over-wintering eggs.

GENERAL

FOREST TENT CATERPILLAR (Malacosoma disstria)

The forest tent caterpillar was one of the most conspicuous
insect pests of shade and fruit trees during 1948. A severe outbreak
of this insect occurred in the city of Billings, causing considerable
damage where, in some cases, complete defoliation of smaller trees
was observed. Extensive control measures were applied against
this pest.

COTTONWOOD LEAF BEETLE (Chrysomela scripta)

Reports have been received of damage caused by the cotton-
wood leaf beetle to cottonwood trees in shelter belts. This insect
occurs over all parts of the state but it has been reported as doing
the most damage to trees in the western and northern counties.

BRACHYRINUS MERIDIONALIS

This insect has been a pest of lilac and other shrubs in some
sections of the town of Hamilton for several years. Up to this time
it has spread very little from the point of its initial introduction
into Hamilton. This insect is a European species which has been
previously noted only in the San Francisco bay region. The adult
beetles are active mainly at night at which time they damage lilacs
and other shrubs by completely defoliating them. They may be
found during the daylight hours hiding under the trash and other
debris in the immediate vicinity of the shrubs on which they are
feeding. This pest is similar in appearance to the strawberry root
weevil.

MONTANA INSECT PESTS, 1947 AND 1943 21

INSECTS INJURIOUS TO STORED PRODUCTS

GRAIN INSECTS

In the past the most important insects infesting stored grain
and cereal products in Montana have been the confused flower
beetle (Tribolium confusurn) , the flat grain beetle (Laemophloeus
minutus), and the sawtooth grain beetle (Oryzaephilus suri-
namensis) . Inspections made during the winter of 1947-48 revealed
that many elevators and farm granaries were infested with these
insects. In all cases, it was found that the infestations were brought
about by either improper storage facilities or by storing grain with
too high a moisture content.

Although infestations of these insects occurred in all parts of
the state, the largest number of infestations were found in the
northwest section of Montana. No granary weevils (Sitophilus
granarius) were found during the survey.

HOUSEHOLD INSECT PESTS

CEREAL INSECTS

An unusually large number of requests for identification and
control of household cereal insects has been received in the State
Entomologist's office during the last two years. The most prevalent
of these pests seems to be the confused flower beetle (Tribolium
confusum) , and the flat grain beetle (Laemophloeus minutus) .
These have been recorded infesting flour and other cereal products
stored in the home and they are common all over the state.

OTHER HARMFUL INSECTS

TERMITES (Isoptera)

There has been a marked increase in the number of requests
received in the State Entomologist's office for information con-
cerning termites and their control. These requests have come from
every section of the state with the exception of the northeast
counties. Considerable damage to flooring and studding in homes
was observed in Glendive and Billings. It appears that damage
attributed to these insects is becoming more common from year
to year.

DERMESTIDS (Dermestidae)

These insects occur commonly over the state and have been
reported causing damage to food, clothing, carpets, and furniture.
Dermestids have apparently been especially noticeable during
1948, particularly in the vicinity of Great Falls.

22 MONTANA EXPERIMENT STATION BULLETIN 457

INSECTS INJURIOUS TO MAN AND ANIMALS

MAN
MOSQUITOES (Culicidae)

Weather conditions during the last biennium have been very
favorable for mosquito breeding. High water and heavy rains
during the spring have produced ideal breeding conditions for
these insects, and many areas have suffered the heaviest infesta-
tions in years. Considerable interest has been shown in mosquito
control programs in most of the heavily infested areas. The State
Entomologist's office was consulted on mosquito control programs
by Glasgow, Chinook, Havre, Miles City, Malta, Harlem, and Twin
Bridges. Active control programs have been carried out in Glas-
gow, Malta, Miles City, and Great Falls, during the last two years.
Considerable success has been reported from these campaigns.
However, better results will be obtained when it is realized that
airplane spraying and wholesale distribution of D.D.T. sprays are
not the ultimate solution to the mosquito problem. The distribution
of D.D.T. sprays along with a well planned program of eliminating
mosquito breeding places, will, over a period of time, result in a
less expensive program and more effective control.

LIVESTOCK

CATTLE GRUBS (Hypoderma bovis and Hypoderma lineatum)

Cattle grubs have been a serious pest to livestock for many
years. During the last few years an increased interest on the part
of stockmen has been shown in the subject of controlling these
pests. Both the early cattle grub (H. lineatum) and the late cattle
grub (H. bovis) are found in practically all sections of Montana.
During the last biennium, research has been carried on by the
State Entomologist's office and the Montana Agricultural Experi-
ment Station to determine the distribution of these two species.
There are some limited areas in the Gallatin Valley, the Big Hole
in Beaverhead County, and possibly others, where H. lineatum
does not occur.

Preliminary studies are under way to determine the emerg-
ence dates of these grubs in different parts of the state. Observa-
tions show that due to differences in seasonal temperatures,
emergence dates may vary rather widely from year to year and
from region to region. In some cases such differences may be
observed within very narrow geographical limits.

As was stated, the interest in cattle grub control among
ranchers has become more evident during the past two years and
in some sections the ranchers are now cooperating to carry on
control work on an area, rather than an individual basis. In general,

MONTANA INSECT PESTS, 1947 AND 1948 23

results of such programs have been quite successful. These
ranchers report that the incidence of grub infestations has been
greatly reduced.

CATTLE LICE

The interest shown by ranchers in louse control parallels that
shown in cattle grub control, even though cattle louse problems
have existed for years in varying degrees and intensity. While the
reasons for seasonal variations in intensity of infestations are
fairly well established, the variations which occur from year to
year remain unexplained. There are three types of cattle lice which
have a general distribution over the state. They are the long nose
cattle louse (linognathus vituli), the short nose cattle louse
(Haematopinus curysternus), and the biting louse (Bovicola
bovis) . With the development of new insecticides which are more
effective against lice, it is expected that cattle lice control will
soon be an established practice in the livestock industry. An
increasing number of growers are now including cattle lice control
in their herd management programs with very successful results.
The State Entomologist's office is being requested to furnish
information on materials and methods for setting up and carrying
out these programs.

HORN FLIES (Haematobia irritans)

For many years these insects have been pests of livestock
over the entire state. Now that effective methods of controlling
horn flies have been developed, it has become evident that heavy
infestations of these insects have been responsible for preventing
many animals from making normal gains in weight. In many cases
there are indications that the presence of horn flies may be in part
responsible for the over-grazing of certain areas and the under-
grazing of others because of the animals' attempts to avoid the
flies.

SHEEP TICKS (Melophagus ovinus)

Sheep ticks often cause considerable loss in the sheep and
wool industries. They are common in all of the sheep raising areas
of Montana. Heavily infested flocks do not gain weight normally;
lambs are occasionally killed by the insects; and a poor grade of
wool is often produced. Sheep ticks are apparently more prevalent
at the present time than they have been in previous years. The
reasons for this increase in tick populations have not been estab-
lished. Many of the new insecticides show considerable promise
in controlling this pest, and growers, in general, have shown an
increased interest in sheep tick control.

24 MONTANA EXPERIMENT STATION BULLETIN 457

BIENNIAL REPORT OF THE MONTANA STATE APIARIST

1947 AND 1948

The State Apiculture Law which was passed by the 13th
Legislative Assembly in 1947, has done much to stabilize the bee-
keeping industry in Montana. The enforcement of this law has
prevented honey producing areas from becoming over-stocked;
it has helped greatly in enforcing disease control; and it has
brought about a more harmonious relationship between the bee-
keepers of this state.

In Lake County in 1946, the honey producing area was
extremely overcrowded. Even during the war years, when honey
was selling at a high price, the beekeepers in this area were not
able to make their operations pay. After the law was passed, these
producers called upon the State Apiculturist's office to meet with
them to divide this territory into productive, economic units. As a
result of this meeting, it was agreed that each of the different
producers within this area would voluntarily move their locations
as close as possible to their established bases of operation. Con-
flicting locations were abandoned and for the most part, the
crowded conditions were corrected. The following year, honey
production in this area was considerably greater than it had been
in several years past and reports from that section this year
indicate that the 1948 crop will far exceed that of last year. In
this same locality in 1946, 6 percent of all of the colonies inspected
were diseased. This year's inspection showed that only 1.1 percent
of the colonies were diseased. Similar situations have been
observed occurring in other parts of the state.

American foul brood is the only bee disease of economic
importance in Montana. After a colony has become infected, the
only method of controlling this disease is to burn all of the equip-
ment which has come in contact with the diseased bees or honey.
One of the main factors which makes disease control difficult is
the runaway swarms of bees which locate their nests in buildings,
trees, and other natural sites. Such colonies cannot be inspected
and are very susceptible to American foul brood. In the past two
years nearly seven hundred of these colonies have been destroyed
by the State Apiarist. From American foul brood control programs
conducted by various State and Federal agencies, it appears that
sulfathiazole gives the most effective results in preventing this
disease. It is the general belief of most workers that diseased
colonies should be destroyed and that the most practical use of
sulfathiazole is in preventing the occurrence of the disease. The
use of this material has made it possible to reclaim territory that
was previously abandoned due to the prevalence of American foul
brood. Colonies in the Helena Valley at one time were 85 percent

MONTANA INSECT PESTS, 1947 AND 1948 2S

infected with American foul brood. By careful inspection and the
use of sulfathiazole, this figure has been reduced to six-tenths
percent infection.

There has been a great increase in the bee industry in the
last few years. In 1941, thirty-six thousand colonies were recorded
in the state. This year, sixty-five thousand colonies have been
registered. It appears, however, that the next few years will show
a "leveling off" or even a decrease in bee populations. This state-
ment is based on the fact that many honey producing areas in
Montana are now over-stocked. In addition, there has been an
appreciable drop in honey prices, while the costs of labor and
equipment are steadily increasing. These conditions will make it
impracticable for beekeepers to operate bees on marginal territory.

There is much that might be done to aid the beekeeper in
producing larger honey crops. This phase of the work of the State
Apiarist is necessarily limited because at present, most of his time
must be spent on disease control and law enforcement. If adequate
personnel were available, more time could be devoted to assisting
the beekeepers in solving their problems.

The value of the bee industry in agriculture is generally not
recognized. According to the United States Department of Agri-
culture, bees are 10 to 20 times more valuable as pollinators than
they are for the honey or beeswax which they produce. With the
extensive use of new organic insecticides which are very toxic to
wild bees, many of the natural pollinators are being destroyed and
honey bees may become more and more essential for the pollina-
tion of agricultural crops.

26

MONTANA EXPERIMENT STATION BULLETIN 457

TABLE OF AMERICAN FOUL BROOD INCIDENCE IN COLONIES

INSPECTED BY THE STATE APIARIST

1947

No. colonies
inspected

Blaine 57

Carbon 24

Cascade 372

Custer 70

Flathead 231

Gallatin 1007

Granite 600

Lewis and Clark 26

Madison 54

Musselshell 73

Phillips 171

Ravalli 606

Rosebud 31

Treasure 2

Yellowstone 308

3632

1948

Dawson 38

Fergus 846

Flathead 897

Gallatin 1068

Golden Valley 60

Jefferson 79

Lake 336

Lewis and Clark 162

Madison 586

Missoula 302

Ravalli 934

Richland 142

Roosevelt 37

Sweetgrass 470

Valley 212

Wheatland 35

No. diseased

diseased

colonies

colonies

2

3.3

0

0

19

5.1

9

10.4

24

10.3

16

1.5

0

0

2

7.7

4

7.0

1

1.3

12

7.0

19

3.1

1

3.2

0

0

17

5.5

125

3.5

0

0

87

10.3

46

5.1

9

.8

0

0

0

0

4

1.1

1

.6

4

.7

6

1.9

38

4.0

0

0

0

0

0

0

0

0

1

2.8

6240

109

1.7

INDEX PAGE

INTRODUCTION 3

HARMFUL AND DESTRUCTIVE INSECTS 4

INSECTS INJURIOUS TO CROPS IN GENERAL 4

Grasshopper Control 4

1947 Season 4

1948 Season 5

The Outlook For 1949 7

Other Important Pests 7

Wireworms 7

Garden Slugs 7

Blister Beetles 8

Flea Beetles 8

White Grubs 8

Morman Crickets 8

Ear Wigs 8

INSECTS INJURIOUS TO FIELD CROPS 9

Small Grains 9

Wheat Stem Sawfly 9

Army Cutworms 10

Pale Western Cutworms 11

Hessian Fly 1-

Wheat Stem Maggot 11

Corn 11

Corn Ear Worm L

Seed Corn Maggot - 12

Bumble Flower Beetle 12

Alfalfa 12

Alfalfa Weevil . - - 12

Lygus Bugs 12

Alfalfa Seed Chalid .... 13

Pea Aphis 13

Potatoes 13

Colorado Potato Beetle 13

Potato Psyllid 13

Sugar Beets 13

Sugar Beet Webworm 13

Spinach Leaf Miner — - - 14

Sugar Beet Root Maggot 14

Peas - |4

Pea Weevil 14

INSECTS INJURIOUS TO GARDEN AND TRUCK CROPS 14

Crucifera 14

Cabbage Maggot - 14

Imported Cabbage Worm 15

Cabbage Aphis 15

Root Crops 15

Onion Maggot - 15

Asparagus — 15

Asparagus Beetle 15

INSECTS INJURIOUS TO FRUIT CROPS 15

Apples — - 1^

Codling Moth i6

Oyster Shell Scale 16

Wooly Apple Aphis 1 16

Apple Aphid 16

Rosy Apple Aphis 16

Eye-Spotted Bud Moth 16

Cherries 16

Black Cherry Aphis 16

Cherry Fruit Fly 16

Yellow Jackets 17

Pear Slug 17

Rust Mite 17

Raspberries 17

Raspberry Crown Borer 17

Raspberry Fruit Worm 18

Raspberry Sawfly 18

Prunes and Plums 18

Plum Gouger 18

Plum Aphis 18

Strawberries 18

Strawberry Crown Miner 18

Currants 19

Currant Aphis 19

Currant Fruit Fly 19

INSECTS INJURIOUS TO SHADE TREES AND SHRUBS 19

Evergreens 19

Spruce Gall Aphid 19

Pine Leaf Scale 19

Pine Bark Aphid 19

Red Cedar Aphid 19

Ash 20

Green Ash Aphis 20

General 20

Forest Tent Caterpillar 20

Cottonwood Leaf Beetle 20

BraGhyrinus Meridionalis 20

INSECTS INJURIOUS TO STORED PRODUCTS 21

Grain Insects 21

HOUSEHOLD INSECT PESTS 21

Cereal Insects 21

Other Harmful Insects 21

Termites 21

Dermestids ...1 21

INSECTS INJURIOUS TO MAN AND ANIMALS 22

Man : 22

Mosquitoes 22

Livestock 22

Cattle Grubs 22

Cattle Lice 23

Horn Flies 23

Sheep Ticks 23

BIENNIAL REPORT OF THE MANTANA STATE

APIARIST— 1947 and 1948 24

TABLE OF AMERICAN FOUL BROOD INCIDENCE IN

COLONIES— 1947-1948 26