s
353.9
E3R
1953 NO. 34
1
JANUARY, 1953
Montana Insect Pests
1951 - 1952
Thirty-Fourth Report
of trie
State Entomologist
SW7E PUBLICA770WS COLLECTION
MONTANA STATE COLLEGE nrr
AGRICULTURAL EXPERIMENT STATION UL I $ \ 2007
BOZEMAN, MONTANA
MONTANA STATE LIBRARY
1515 E. 6th AVE
HELENA, MONTANA 59620
Bozeman, Montana
To His Excellency
Governor J. Hugo Aronson
State House
Helena, Montana
My Dear Governor Aronson:
I am submitting herewith the Thirty-Fourth Report of the
State Entomologist of Montana. This report contains information
concerning insect control programs, the status of the more import-
ant and unusual insects, and a report of the goat weed beetle intro-
duction program.
During the last biennium increasing demands have been made
upon this office. For example. 98 educational and/or demon-
strational meetings were held with a total attendance of 5.548
persons: 1,947 inquiries concerning insect identification, control,
and general information were answered; and 186 publications,
articles, and radio scripts were issued. This is a substantial in-
crease over the previous biennium. hi addition, three educational
motion picture films have been produced.
Since 1945 the demands and requests upon this office have
been gradually increasing and most of these requests have been
met. It is anticipated that very little further expansion of the
activities of this office will be requested or occur during the next
biennium.
Respectfully submitted,
James H. Pepper
| 1[D2 State Entomologist
3 0864 1004 1450 0
MONTANA INSECT PESTS
1951 and 1952
Thirty-Fourth Report Of The State Entomologist
J. H. Pepper J. P. Corkins L. N. Graham
D. R. Merkley N. L. Anderson'
INTRODUCTION
Most of the major insect pests with the possible exception of
alfalfa weevils have been at a general low ebb during the bien-
nium. However, the overall insect damage to Montana agricul-
ture was not appreciably reduced principally due to the increasing
occurrence and activities of several insects which were formerly
considered to be minor pests. General expansion and intensifica-
tion of agricultural programs are expected to cause new insect
problems to develop. Such new insect pests may include those
introduced from other areas as well as native insects which are
adapting themselves to our changing agricultural conditions. Con-
tinued research, vigilance, and the use of modern control methods
should help to prevent serious reverses in our agricultural econ-
omy from new insect pests as well as from those which are already
established.
In past years range and cropland grasshoppers have been the
undisputed leading insect pests of Montana's agriculture. During
the biennium grasshoppers have been at a near historical low
point in occurrence and damage caused. In spite of the reduced
infestations, more than 50,000 acres were treated in 1952 alone.
In the event that conditions, which are unknown as yet, favorable
to the rapid build-up of these insects should occur, outbreaks
could be expected to materialize within a relatively short period
of time. The ultimate objective of the range grasshopper inves-
tigations currently being carried out by this office, in cooperation
with the Agricultural Experiment Station at Montana State Col-
lege, is to determine how grasshopper outbreaks occur and how to
prevent such occurrences. A bulletin in which preliminary studies
on this problem are summarized is now in press. We are now
equipped with the information from these studies to enable us
to carry out a better program of grass protection.
Surveys, and reports from inspections at terminal elevators,
indicate that a serious problem of grain contamination exists1 in
Montana. The Federal Food and Drug Administration is currently
conducting a program the objective of which is to eliminate con-
'State Entomologist; Assistant State Entomologist; Assistant State Apiarist; Assist-
ant Entomologist, Montana Agricultural Experiment Station; Assistant State
Entomologist.
4 MONTANA EXPERIMENT STATION BULLETIN 484
tamination of cereals to be used for human consumption. The
federal regulations which currently apply to other human foods
in intra-state shipment are now being applied to wheat. This office
along with the Montana Agricultural Extension Service has been
called upon to develop a program of preventing contamination of
stored grain. It has been found that the principal sources of con-
tamination to these grains are rodents, birds, insects, and other
animals. Such contamination can be largely eliminated by a pro-
gram of proper storage and sanitation.
Recent research on Montana mosquitoes has provided infor-
mation which indicates that area-wide mosquito control under Mon-
tana conditions may be practicable in the near future. Large-scale
mosquito control can be realized only if an educational program
is successfully conducted. This office is currently planning such
programs to meet this need.
GENERAL FEEDERS
GRASSHOPPERS
1951 SEASON
Grasshopper populations in 1951 were generally lower than
in 1950. Scattered localized infestations of range and crop grass-
hoppers did occur so that some economic damage was experienced
in nearly every county. Grasshopper control is now the complete
responsibility of individual land owners except in cases where
public domain is involved. Therefore, more intensive educational
programs were conducted. A total of 53 educational meetings were
undertaken which were attended by 2.263 people. In addition,
educational programs were carried out through newspapers, radio,
and bulletins. It is estimated that 120.000 acres of cropland and
80,000 acres of rangeland were treated for grasshopper control
during this year.
Melanoplus bivitattus in eastern Montana and Melanoplus
bivitattus and Melanoplus meocicanus in western Montana were
the principal species involved in damage to cropland. A some-
what spotted but relatively intense early season outbreak of
Aeropedellus clavatus occurred in northcentral Montana causing
considerable early damage to grain crops.
As compared to the previous two years, Melanoplus mexi-
canus, Metator pardalinus, Aulocara elliotti, and Drepanopterna
femoratum were generally present in much lower populations.
Camnula pellucida appeared to be increasing particularly in
Meagher and Judith Basin counties.
MONTANA INSECT PESTS, 1951-1952 5
1952 SEASON
This was a relatively low grasshopper year. A few scattered
light to moderate infestations of range and crop hoppers occurred.
Most of these infestations were localized in nature. Populations of
Melanoplus mexicanus, Metator pardalinus, Aulocara elliotti, and
Drepanopterna femoratum appeared to be below those experi-
enced during the previous three or four years. Melanoplus bruneri,
Camnula pellucida, and Chorthippus longicornus appeared to be
present in increased numbers as compared with the previous three
or four years. An infestation of Bruneria brunnea occurred in the
Dryhead area of Big Horn and Carbon counties. An infestation of
Asemoplus montanus occurred at approximately 6,000 feet on the
forest preserve in southern Ravalli County. The Asemoplus mon-
tanus appeared to be feeding on Stipa comata, Poa pratensis and
Bromus sp.
OUTLOOK FOR 1953
It would appear that we are either approaching or experienc-
ing a general low point in grasshopper infestation cycles. Un-
fortunately, grasshopper infestations are as yet largely unpre-
dictable. On the basis of past history of Montana grasshopper
cycles, only scattered light infestations are expected in 1953. If
conditions, which are as yet unknown, favorable to rapid grass-
hopper population increases should occur, the potential to start an
outbreak is now present.
OTHER IMPORTANT PESTS
MORMON CRICKETS (Anabrus simplex)
Only one infestation of Mormon crickets was found or re-
ported in 1951. This was a moderate non-gregarious infestation in
Chouteau County, north of Shonkin, involving three to four sec-
tions. This infestation was re-checked in 1952 and it was found
that approximately the same area was infested; however, popu-
lations of crickets were much lighter and those present were for
the most part confined to the coulee bottoms.
Three light to moderate Mormon cricket infestations were
found on and along the Big Horn Mountains in Big Horn and
Carbon counties in 1952. These infestations included about two
sections just north of Pryor gap, one section just south of Dryhead
Creek, and two sections on Grapevine Creek.
Several gregarious bands of Mormon crickets were reported in
the upper Blackfoot River Valley in the general area around
Ovando, Helmville, and Lincoln in 1952. Unfortunately, these re-
ports were received late, and the area was not surveyed early
6 MONTANA EXPERIMENT STATION BULLETIN 484
enough in the season to provide proper diagnosis of the situation.
Reports from other states indicate that Mormon crickets are
on a general upward trend throughout the western outbreak areas
of the United States and several outbreaks have already occurred.
All of the evidence indicates that Mormon cricket outbreaks may
occur in Montana within the next few years.
GARDEN SLUGS (Agriolimax sp.)
Garden slugs continue to be an important pest to home
gardens, particularly in the western three quarters of the state.
They are either becoming more numerous or people are becoming
more cognizant of slug infestations. Baits containing metaldehyde
are the primary recommendation for slug control.
WHITE GRUBS (Phyllophaga sp.)
Occasional infestations of white grubs in gardens were re-
ported from various areas of the western half of the state during
the biennium. No cases of infestations attacking field crops were
reported. A soil treatment with either DDT or chlordane is cur-
rently recommended for white grub control.
ARMY CUTWORMS (Chorizagrotis auxiliaris)
In 1951 small localized infestations occurred in Liberty, Choteau,
Judith Basin, Fergus, Phillips, and Prairie counties. Similar in-
festations occurred in Toole, Pondera, Hill, Cascade, and Yellow-
stone counties in 1952. Wherever infestations were severe enough
to warrant control, spray applications using lj/? to 2 pounds of
toxaphene per acre were used with apparent good success.
PALE WESTERN CUTWORMS (Agrotis orthogonia)
No cases of pale western cutworm infestations were reported
or observed during the biennium.
RED-BACKED CUTWORMS (Euxoa ochrogaster)
In 1951 the red-backed cutworm occurred in damaging num-
bers in sugar beet fields, grain fields, and gardens throughout
parts of western Montana. Damaging infestations were reported in
an alfalfa field in Prairie County, an alfalfa field in Mineral
County, and a grain field in Glacier County in 1952. A late after-
noon spray application of two pounds of toxaphene per acre was
reported to give satisfactory results.
WIREWORMS (Elateridae family)
Reports of severe damage to small grains, winter wheat in
particular, have been received from nearly all counties in the
state during the reporting period. In addition, a few reports of
damage to potatoes have been received from the northcentral and
western areas of the state.
MONTANA INSECT PESTS, 1951-1952 7
Seed treatment applying one ounce of lindane per acre to
spring seeded wheat has proved to be an effective control. In ad-
dition, recently completed tests indicate that the same treatment
is also effective on fall seeded winter wheat.
BLISTER BEETLES (Meloidae family)
Scattered cases of damage to sugar beets, alfalfa, gardens, and
ornamental shrubbery occurred in many parts of eastern Mon-
tana during 1951. No field crop damage and very little garden or
ornamental damage by blister beetles was reported in 1952. DDT
spray application appears to be controlling the blister beetles un-
der all circumstances of occurrences.
FLEA BEETLES (Epitrix sp. and Systena sp.)
Severe infestations of the potato flea beetle Epitrix sp. oc-
curred in the spring of 1951 on seedling sugar beets in Blaine,
Phillips, Richland, Dawson, Prairie, Rosebud, Custer, Treasure,
Big Horn, and Yellowstone counties. The application of 12 to 15
pounds of 5 percent DDT dust per acre resulted in erratic control.
Where 5 percent DDT dust was used at 20 pounds per acre, eco-
nomic control was more consistent. In 1952 severe damage to
seedling sugar beets occurred in Richland County with less severe
damage occurring in Blaine, Prairie, Rosebud, and Carbon coun-
ties. Five percent DDT dust applied at the rate of 20 pounds per
acre was used in Richland County in 1952 with consistently good
results.
The banded flea beetle, Systena sp., was not reported in eco-
nomic numbers in 1951. In 1952 unusually large populations of
banded flea beetles occurred during June and early July in many
alfalfa fields of southcentral and southeastern Montana. Numer-
ous cases of the flea beetles causing serious defoliation were ob-
served.
THISTLE BUTTERFLY CATERPILLARS (Vanessa cardui)
This insect did not occur in appreciably large numbers in
1951. In early June of 1952 many large flights of painted lady
butterflies were observed over various parts of the western three-
quarters of Montana. By late June, the caterpillars or larval form
of this insect were abundant in many localities. Larval feeding
was largely confined to various species of thistles; however, re-
ports were received of severe damage to beans, potatoes, clover,
corn, cabbage, and hollyhocks. Toxaphene sprays were success-
fully used for control.
FIELD CRICKETS (Acheta assimilis)
Occasional cases of field crickets damaging alfalfa seed in the
shock occurred during the biennium in northeastern Montana. In
8 MONTANA EXPERIMENT STATION BULLETIN 484
1952 an early spring field cricket infestation occurred in a local-
ized area of Big Horn County involving approximately four farms.
The crickets were moving from stubble fields into the winter
wheat fields and seriously damaging the crop. A combination
spray of toxaphene and chlordane controlled this infestation. The
insecticides were used in a combination of Yi pound of chlordane
per acre and one pound of toxaphene per acre.
EUROPEAN EARWIGS (Forficula auricularia)
This unsightly insect is now common in all of Montana west
of the Continental Divide and in the southwestern portion of Mon-
tana east of the Continental Divide. Unusually severe populations
occurred in the late summer of 1952 in many homes and gardens
of northwestern Montana. Both chlorinated hydrocarbon insecti-
cidal sprays and baits were used to combat these infestations.
SPITTLEBUGS (Cercopidae family)
In 1952 spittlebugs became quite prevalent over much of
Montana west of the Continental Divide. For the most part their
activities were confined to weeds; however, occassionally gardens
were invaded with some damage resulting. They were also ob-
served to be present in alfalfa fields. No cases of damage to field
crops were reported.
WESTERN CHINCH BUGS (Blissus occiduus)
During the reporting period, the western chinch bug occurred
only in 1951 where it caused damage to crested wheat grass in
Teton County and to several barley fields in Fergus County. These
infestations were localized but the damage was severe.
INSECTS DESTRUCTIVE OF FIELD CROPS
SMALL GRAINS
CRESTED WHEAT PLANT BUGS (Labops hesperus)
In 1951 five or six spring and winter wheat fields in Choteau
County received severe marginal damage from crested wheat
plant bugs which had moved from adjacent crested wheat grass
fields. Similar situations were reported near Pryor, Montana, in
1938. Similar damage also occurred in several scattered areas
throughout Montana in 1952. Such infestations were, readily con-
trolled with a marginal spray application of two to three pounds
of DDT per acre.
Extremely severe damage to crested wheat grass plantings
occurred in Ravalli, Missoula, and Cascade counties in 1952. In
some cases the damage was so severe that when accompanied by
grazing it resulted in crested wheat grass plantings being killed.
MONTANA INSECT PESTS, 1951-1952 9
WESTERN WHEAT APHID (Brachycolus tritici)
In 1951 the western wheat aphid was reported only in southern
Broadwater County. Control measures were attempted by the
aerial application of one pound of parathion per acre. These meas-
ures were unsuccessful. The leaf sheaths of the wheat plants were
curled by the time the insecticide was applied. This provided pro-
tection for the aphids which were present inside of the sheath.
Most of the farmers worked their summer fallow so as to keep it
free from volunteer wheat, barley, and grasses. This practice pre-
vented over-wintering aphid colonies from establishing them-
selves in the fields and resulted in only spotted light infestations
in this area in 1952.
Other spotted infestations were reported in 1952 in south-
western Choteau County and eastern Richland County.
ENGLISH GRAIN APHID (Macrosiphum granarium)
Late June and early July of 1951 were relatively cool and wet
in western Montana. By early July, English grain aphid popula-
tions had built up to alarming numbers in Ravalli, Missoula,
Sanders, Lake, and Flathead counties. Heavy flights occurred
generally throughout this area in mid-July, and specimens were
picked up by aircraft as high as 8,000 feet altitude. Some controls
were attempted using aircraft application, applying Yi pound of
parathion and one gallon of oil per acre. For the most part these
control measures were successful but tended to be somewhat er-
ratic. In the latter part of July the weather in western Montana
turned hot and dry allowing ^predators, principally syrphid fly
larvae, to rapidly reduce grain aphid populations. In mid-August
the weather turned damp and cool in an area involving parts of
Glacier, Toole, Pondera, and Teton counties. By the first of Sep-
tember, alarming populations of English grain aphids were present
in many of the grain fields, and some shriveling of kernels was
already evident in the ripening grain. Airplane spraying was im-
mediately initiated applying 3/8 of a pound of parathion in two
gallons of diesel oil per acre. The resulting control was excellent.
In 1952 alarming numbers of English grain aphids appeared
in Daniels, Sheridan, and northern Valley counties following a
cool wet period in late July. Early August turned hot and dry re-
sulting in the aphid population rapidly falling below the eco-
nomic level principally due to the activities of ladybird beetles.
WHEAT STEM SAWFLY (Cephus ductus)
The 1951 wheat stem sawfly survey indicated that severe in-
festations occurred in Teton, Pondera, Glacier, Toole, Lincoln,
Chouteau, Cascade, and Daniels counties, with lesser infestations
10 MONTANA EXPERIMENT STATION BULLETIN 484
in most of the other major wheat growing counties east of the
Continental Divide. An estimation of losses was prepared by the
Bureau of Entomology and Plant Quarantine of the United States
Department of Agriculture. According to this estimate, a loss of
approximately 1,422,751 bushels of wheat was attributed to the
wheat stem sawfly in Montana during this season.
At the time of this writing, the 1952 sawfly survey was not
completed. However, it does appear that in general the sawfly in-
festation was similar to that of 1951.
WHEAT STEM MAGGOT (Meromyza americana)
Scattered infestations of wheat stem maggots occurred in
Fallon, Wibaux, Prairie, Dawson, McCone, Richland, Daniels, and
Lake counties in 1951 and in Sweetgrass, Stillwater, Phillips,
Toole, Daniels, Sheridan, Richland, McCone, Dawson, Wibaux,
and Custer counties in 1952. In all cases less than 5 percent of the
plants were infested with average infestations of from 1 to 2 per-
cent.
WHEAT JOINTWORM (Harmolita tritici)
A few scattered light infestations of wheat jointworm oc-
curred in Yellowstone and Stillwater counties in 1951. In 1952 the
wheat jointworm was more prevalent in northern Sweetgrass
and Stillwater counties where it inflicted severe damage. This
jointworm also occurred in Phillips and Daniels counties in 1952.
In the event that damage of the type that occurred in northern
Sweetgrass and Stillwater counties in 1952 should become more
widespread, this insect could become one of the leading pests of
wheat.
GRAIN THRIPS (Limothrips cerealium)
Spotted moderate to severe infestations of grain thrips in
oats occurred in Stillwater County in 1951. This is the only out-
break reported or observed during the biennium.
A WHEAT HEAD ARMYWORM (Faronta sp.)
Numerous infestations of a wheat head armyworm occurred
in Chouteau, Cascade, and Fergus counties, during late July and
early August of 1952. In most cases the worm was not observed
until found in the harvested wheat. This insect was feeding on the
mature, or nearly mature, wheat kernels. In all cases observed,
the insects were not prevalent enough to cause damage of eco-
nomic importance. This insect was not reported or observed during
1951.
A WHEAT LEAF SAWFLY (Tenthredinidae family)
Extensive infestations of a wheat leaf sawfly were found in
MONTANA INSECT PESTS, 1951-1952 11
Broadwater County during June 1952. The infestations were large-
ly on winter wheat and in all cases the wheat was far enough ad-
vanced so that the leaf feeding damage inflicted by the sawfly
was not of economic importance. This was the only known oc-
currence of this insect during the biennium.
CORN
EUROPEAN CORN BORER (Pyrausta nubilalis)
The first known occurrence of European corn borer in Mon-
tana was discovered October 20, 1951, in a corn house near Savage.
Corn borer larvae were found to be tunneling the cobs of this seed
corn.
A survey in 1952 revealed very light infestations of European
corn borers in irrigated corn in Prairie, Dawson, and Richland
counties. No borer infestations were found in dryland corn. To
date the borer has not been found in alarming numbers. An ex-
tension program is being organized to advise farmers what to look
for in determining the presence of corn borers and to acquaint
farmers with methods of handling corn fields and products from
those fields in such a manner as to prevent the borers from over-
wintering successfully.
CORN EARWORM (Heliothis armigera)
The corn earworm was not prevalent during the first year of
the biennium. In late July of 1952 numerous moderate to severe
infestations were found on irrigated field and garden corn in the
southeastern, southcentral, and western parts of the state.
BUMBLE FLOWER BEETLE (Euphoria inda)
A single infestation of bumble flower beetles occurred on
corn in Cascade County during the late summer of 1951. Consider-
able damage to the corn ears was experienced. This was the only
infestation observed or reported during the biennium.
ALFALFA AND CLOVER
ALFALFA SEED CHALCID (Bruchophagus gibbus)
Very light and widely scattered infestations of alfalfa seed
chalcid occurred over most of the alfalfa seed producing areas in
the state during the biennium. No inquiries were received re-
garding this insect, and no extremely severe infestations are
known to have occurred.
ALFALFA WEEVIL (Hyper a postica)
All, or parts of, Madison, Park, Sweetgrass, Stillwater, Car-
bon, Golden Valley, Fergus, Phillips, Petroleum, Garfield, Mus-
12 MONTANA EXPERIMENT STATION BULLETIN 484
selshell, Yellowstone, Big Horn, Treasure, Rosebud, Powder
River, Custer, and Prairie counties are now known to be infested
with economic populations of alfalfa weevils. During the past two
years, this pest has consistently caused more damage to alfalfa
than any other insect. During the biennium, the alfalfa weevil
has been one of the more important economic insect pests to Mon-
tana agriculture. The early spring chlordane treatment recom-
mended in 1951 was effective where used properly, but its use
was limited due to the relatively high cost per acre for treatment.
During the fall of 1951 a 20-minute, 16 mm. color sound motion
picture entitled "Alfalfa Weevil Control" was prepared by this
office in cooperation with the Agricultural Experiment Station
at Montana State College. In 1952, the film was used by this of-
fice at 22 alfalfa weevil control meetings which were attended by
1,258 people. In addition, it had 9 other showings to a total at-
tendance of 809 people. This educational effort along with the
lower cost of dieldrin application resulted in a large percentage
of the infested acreage being treated with dieldrin in the early
spring of 1952.
In general, the alfalfa weevil infestation and damage appear-
ed to be moderate in 1951. In 1952 consistently higher populations
and more than average damage was noted. For the first time in
1952 it was evident that extremely high populations of adults
caused damage to the alfalfa largely through their egg-laying ac-
tivities. The newly recommended early spring dieldrin treatment
was very successful, and it has resulted in large returns in terms
of alfalfa production at a relatively low cost of treatment per
acre.
LYGUS BUGS (Lygus sp.)
All alfalfa seed areas observed in 1951 had economic infes-
tations of Lygus bugs during mid and late summer. The same was
true in 1952 except that Lygus populations in southeastern Mon-
tana appeared to be unusually high. Most alfalfa seed growers are
now using DDT and toxaphene spray treatments for the control
of this sucking insect pest.
SWEETCLOVER WEEVIL (Sitona cijlindricollis)
Scattered moderate to heavy infestations of sweet clover
weevils occurred over many areas of the state in 1951 with a few
cases of marginal damage to alfalfa being reported. In the spring
of 1952, severe defoliation by adult sweetclover weevils was evi-
dent in nearly all parts of the state; again a few cases of marginal
damage to alfalfa occurred.
CLOVER APHID (Anuraphis bakeri)
Economic populations of clover aphids were present in most
MONTANA INSECT PESTS, 1951-1952 13
seed clover fields of western Montana during the biennium. In
addition, an infestation was reported in a seed clover field in
Yellowstone County in 1952. This insect seems to occur in eco-
nomic numbers in seed clover fields frequently enough to justify
a preventative benzene hexachloride spray program.
LESSER CLOVER LEAF WEEVIL (Hypera nigrirostris)
During the biennium, the lesser clover leaf weevil continued
to be present in economic numbers in the seed clover fields of
western Montana.
In 1952 this weevil was found to be present in some irrigated
pastures in Big Horn and Yellowstone counties where it was caus-
ing severe defoliation to the clover and greatly reducing the food
value of the infested pastures. Control measures under these par-
ticular circumstances have not as yet been worked out.
SMALL MILKWEED BUG (Lijgaeus kahnii)
The small milkweed bug has been observed to be present in
insignificant numbers in many southeastern Montana alfalfa
fields. A severe infestation of this insect occurred in early June
of 1952 in an alfalfa field in Treasure County. They were report-
ed to be killing the alfalfa plants.
POTATOES
COLORADO POTATO BEETLE (Leptinotarsa decemlineata)
Scattered moderate to heavy infestations of Colorado potato
beetles occurred in most of the potato growing areas of the state
during the biennium. Many of the potato growers are somewhat
reluctant to carry out an insecticidal control program; conse-
quently, in most cases only the more severe infestations were
treated.
Aerial spraying for Colorado potato beetle control was tested
on three fields in the Gallatin Valley in 1952. The spraying was
accomplished with an Aeronca Champion spray plane applying
one pound of DDT per acre with diesel fuel as a solvent at a total
volume of one gallon per acre. The fields had moderate to heavy
infestations of potato beetles and this spray application eliminat-
ed the infestation. Some foliage burning was noted; however, this
burning was not extensive enough to affect yields. The potato
plants in the test fields were somewhat smaller than average for
late summer and the rows were not closed in as would normally
be the case. A total volume of one gallon per acre appeared to be
adequate for Colorado potato beetle control on these smaller
potato plants.
POTATO PSYLLID (Paratrioza cockerelli)
A severe infestation of potato psyllid was observed in Dawson
14 MONTANA EXPERIMENT STATION BULLETIN 484
County in 1951. This is the only infestation observed or reported
during the biennium.
SUGAR BEETS
SUGAR BEET ROOT MAGGOT (Tetanops aldrichi)
Several infestations of sugar beet root maggots were reported
in Richland County and in western Montana in 1952. This is the
only occurrence reported or observed during the biennium. Seed
treatment with aldrin appears to control this pest.
SUGAR BEET ROOT APHID (Pemphigus betae)
No economic infestations of sugar beet root aphids were re-
ported or observed during the biennium.
BEET WEB WORM (Loxostege sticticalis)
Only one infestation of beet webworm was reported or ob-
served during the biennium. This single occurrence was a moder-
ate infestation found on sugar beets in Prairie County in late
August 1952. In this particular case the beets were far enough ad-
vanced so that control measures were not advisable.
SPINACH CARRION BEETLE (Silpha bituberosa)
No economic infestations of spinach carrion beetles were re-
ported or observed during the biennium.
SPINACH LEAF MINER (Pegomya hyoscyami)
Light to moderate infestations of spinach leaf miners occur-
red on sugar beets in Yellowstone County during June of 1952.
Control measures were not attempted, and this is the only known
occurrence of this insect during the biennium.
PEAS AND BEANS
PEA APHID (Macrosiphum pisi)
Several fields of canning peas in Carbon County were mod-
erately to heavily infested with this sucking insect in 1951. Con-
trol measures with tetraethyl pyrophosphate were instigated.
Other than normal populations in alfalfa fields, no further infes-
tations were reported or observed during the biennium.
PEA WEEVIL (Bruchus pisorum)
No economic infestations of pea weevils were observed or re-
ported during the biennium.
INSECTS DESTRUCTIVE OF GARDEN AND TRUCK CROPS
CRUCIFERAE
CABBAGE MAGGOT (Hylemya brassicae)
Reports and observations indicate that the occurrence of cab-
MONTANA INSECT PESTS, 1951-1952 15
bage maggot during the biennium was neither more nor less se-
vere than in previous years. This garden pest appears to be com-
mon throughout the entire state and is readily controlled with a
chlordane treatment at the time of planting.
IMPORTED CABBAGEWORM (Pieris rapae)
No severe outbreaks of this pest of cruciferae were reported
or observed during 1951. This insect did occur over most of the
state causing considerable damage, particularly in many western
Montana gardens, in 1952.
ROOT CROPS
ONION MAGGOT (Hylemya antiqua)
Reports and inquiries indicate that onion maggot infestations
in gardens were normal during the biennium. Chlordane treat-
ment at the time of planting appears to be successful in prevent-
ing onion maggot damage.
ONION THRIP (Thrips taboci)
Onion thrips were present in Ravalli County during the sum-
mer of 1952. They were not found to be causing economic damage.
ASPARAGUS
ASPARAGUS BEETLE (Criocerus asparagi)
During 1952 asparagus beetles were found and reported to
be causing economic damage to asparagus plantings in western
Montana, particularly in Ravalli and Lake counties. No reports
were received during 1951.
INSECTS DESTRUCTIVE OF FRUIT CROPS
ORCHARDS
BLACK CHERRY FRUIT FLY (Rhagoletis fausta)
1951
In 1951 there was a limited sweet cherry crop. Therefore, no
extensive control or trapping program was conducted by the
growers. Experimentation comparing the efficiency of trap board
and attractant type traps as well as various cherry fruit fly con-
trols was conducted.
1952
In 1952 the sweet cherry crop was above average. An in-
tensive trapping program was conducted to determine emergence
dates and adult populations. In addition, two types of insecticidal
controls were compared. For these purposes two orchards with
histories of fruit fly infestations were selected. One of the orchards
16 MONTANA EXPERIMENT STATION BULLETIN 484
was in the southern area and the other in the northern area of
the east shore of Flathead Lake.
One orchard was sprayed with two applications of parathion
and one application of tetraethyl pyrophosphate. Individual
counts of 10,136 cherries showed no fruit fly infestation.
The other orchard was dusted with lead arsenate and sulphur.
Individual counts of 7,243 cherries showed 30 fruit fly infested
cherries.
A survey to determine the incidence of black cherry fruit fly
in bitter cherry, a native wild cherry, was conducted. Individual
counts of 5,016 fruits were made with negative results.
RUST MITE (Phyllocoptes sp.)
Populations of rust mites in the sweet and sour cherry trees
of western Montana were below economic levels in 1951 and 1952.
PEAR SLUG (Caliroa cerasi)
Light to moderate infestations of pear slugs occurred in many
commercial and home orchards throughout western Montana dur-
ing the first year of the biennium. Reports indicate that this in-
sect pest of stone fruits was even more prevalent and caused more
extensive damage in 1952. Post-harvest toxaphene sprays were
used to combat this pest.
BLACK CHERRY APHID {Myzus cerasi)
No reports of black cherry aphid infestations were received in
1951. In 1952 moderate to severe infestations occurred in the sweet
and sour cherry growing areas of Ravalli and Lake counties. Early
spring delayed dormant oil sprays will control this pest.
CODLING MOTH (Carpocapsa pomonella)
No unusual outbreaks of codling moth were reported or ob-
served during the biennium. Reports and inquiries indicate that
normal infestations occurred in orchards and back yard plantings
where preventative control measures with DDT sprays were not
practiced.
APPLE APHID (Aphis pomi)
No reports of apple aphid infestations were received in 1951.
Generally moderate to severe infestations occurred in apple orch-
ards throughout most of western Montana in 1952.
WOOLLY ELM APHID (Eriosoma americanum)
Woolly elm aphids were abnormally numerous over most of
the state in 1951, inflicting damage to elm and apple trees. Several
reports of infestations in western Montana orchards were received
in 1952.
MONTANA INSECT PESTS, 1951-1952 17
PEAR LEAF BLISTER MITE (Eriophijes pyri)
Infestations of pear leaf blister mite were reported in Lewis
and Clark County in 1951 and Gallatin, Lake, Ravalli, Missoula,
and Mineral counties in 1952.
SMALL FRUITS
MILLIPEDES (Diplopoda class)
Millipedes continued to be a frequent pest of strawberries
throughout the state during the past two years. Rotenone or DDT
dusts effectively control these pests.
CURRANT FRUIT FLY (Epochra canadensis)
The currant fruit fly is widely distributed throughout the
state. It was, however, only reported in Cascade and Gallatin
counties in 1951 and Gallatin, Missoula, Roosevelt, and Garfield
counties in 1952. The current control recommendations are a
spray application using 3 pounds of 50 percent DDT wettable
powder to each 100 gallons of water when 80 percent of the blos-
soms have withered or fallen. This is followed by a second similar
spray application 10 days later.
WESTERN RASPBERRY FRUITWORM (Byturus bakeri)
Infestations of western raspberry fruitworms were reported
in Silverbow County in 1951 and Missoula County in 1952. The
current control recommendations are to spray in the cluster bud
stage with 3 pounds of 50 percent DDT wettable powder to each
100 gallons of water.
RASPBERRY CANE BORER (Oberea bimaculata)
Two infestations of raspberry cane borers were reported in
Lake and Yellowstone counties in 1951. No infestations were re-
ported or observed in 1952.
STRAWBERRY LEAF ROLLER (Ancylis comptana fragariae)
Two infestations of strawberry leaf rollers were reported in
Lake and Stillwater counties in 1952. This pest of strawberries
was neither reported nor observed in 1951.
INSECTS DESTRUCTIVE OF ORNAMENTALS
DECIDUOUS
BOXELDER BUG (Leptocoris trivittatus)
Reports and inquiries regarding boxelder bugs were infre-
quent during the biennium. However, this insect was observed
in many areas throughout the state where boxelder trees are
grown.
ASH BORER (Podosesia syringae fraxini)
Moderate to severe infestations of ash borers were found in
Roosevelt, Richland, and McCone counties in 1951, and in Sheri-
dan and Richland counties in 1952. Two to three paint brush ap-
18 MONTANA EXPERIMENT STATION BULLETIN 484
plied treatments of paradichlorobenzene-linseed oil solutions have
apparently successfully controlled this insect.
GREEN ASH APHID (Prociphilus venafuscus)
Few infestations of green ash aphids were reported dur-
ing the biennium. Infestations occurred in Yellowstone County in
1951, and in Ravalli County in 1952.
ASH FLOWER GALL (Eriophijes fraxiniflora)
Only one infestation of ash flower gall was reported during
the biennium. This occurred in Musselshell County in 1952.
WILLOW LEAF GALL (Pontania sp.)
The willow leaf gall which is caused by a hymenopterous
sawfly appears to have been prevalent during the biennium. Num-
erous reports and inquiries were received regarding this pest.
There are no known control measures at the present time.
POPLAR BORER (Saperda calcarata)
A single infestation of poplar borers reported during the bi-
ennium occurred in Lake County in September of 1951.
COTTONWOOD LEAF-STEM GALL (Pemphigus populi-transversus)
Two infestations of cottonwood leaf-stem gall aphids were
reported during the biennium. These were in Cascade and Yel-
lowstone counties in 1951.
VAGABOND GALL (Mordwilkoja vagabunda)
Infestations of vagabond gall aphids were reported in Pondera
and McCone counties in 1951 and Pondera and Glacier counties
in 1952.
COTTONWOOD LEAF BEETLE (Chrysomela scripta)
A single infestation of cottonwood leaf beetle was reported
in Sanders County in 1952. This is the only known occurrence
during the biennium.
ELM LEAF CURL APHID (Eriosoma americanum)
Elm leaf curl aphids were reported in 1951 from Phillips,
Wibaux, Valley, and Dawson counties. The only infestation re-
ported in 1952 occurred in Chouteau County.
SPIDER MITES (Acarina group)
Many moderate to severe infestations of spider mites occurred
on raspberries, mountain ash, coniferous trees, and other orna-
mentals over most parts of the state during the biennium. Such
infestations were generally more severe during the late summer
months. Tetraethyl pyrophosphate sprays were used in control
programs.
MONTANA INSECT PESTS, 1951-1952 19
SPRING CANKERWORM (Paleacrita vernata)
Localized outbreaks of this pest occurred in central Carbon
County, southern Rosebud County, and southeastern Valley
County in 1951. These outbreaks were largely confined to native
trees on creek bottoms and few control measures were initiated.
An infestation was reported in Chouteau County in 1952.
A TENT CATERPILLAR (Malacosoma sp.)
Only one infestation of tent caterpillars (at Bozeman) was re-
ported in 1951. In 1952, light to moderate infestations occurred
over much of western and southcentral Montana with the prin-
cipal damage being to apple trees and roses. A DDT spray pro-
vided excellent control.
COTTONY MAPLE SCALE (Pulvinaria vitis)
Only a single infestation of this pest was reported during the
biennium. This occurred in 1952 in Lincoln County.
OYSTERSHELL SCALE (Lepidosaphes ulmi)
Oystershell scale is commonly present in most unsprayed
orchards and on back yard fruit trees. In 1952 it was found to be ex-
tremely prevalent on Cotoneaster shrubs in most of western and
parts of eastern Montana. This scale can be controlled with dor-
mant sprays.
BIRCH SKELETONIZER (Bucculatrix canadensisella)
A moderate to severe outbreak of birch skeletonizer occurred
in Lewis and Clark County in 1951. This chewing lepedopterous
pest of birch trees was not reported or observed in 1952.
COTTONWOOD-LEAF MINER (Proleucoptera albella)
This insect pest probably occurs throughout the entire state
along with cotton wood trees. Several cases of severe damage have
been reported from the northcentral section of the state during
both years of the biennium. This pest is frequently heavily para-
sitized so that extensive damage is not expected to be re-occurrent
for long periods of time. No practical control measures are known
at present.
A LEAF ROLLER (Archips sp.)
A tree leaf roller was found and reported to be causing ex-
tensive damage to Russian olives, caragana, and apples in north-
central and northwestern Montana during June of 1952. This is
the only occurrence of this insect reported during the biennium.
CARPENTER WORM (Prionoxystus robiniae)
Only a single infestation of these borers of living trees was
reported during the biennium. This occurred in 1951 in Broad-
water County.
20 MONTANA EXPERIMENT STATION BULLETIN 484
ELM SAWFLY (Cimbex americana)
The elm sawfly, a defoliating pest of elm trees, was reported
only once during the biennium. This occurrence was in Wibaux
County in 1952.
VIRGINIA CREEPER LEAF HOPPER (Erythroneura ziczac)
The hosts of this sucking insect pest are Virginia creeper,
raspberry, apple, and some other plants. The principal occurrence
of this leaf hopper has been on Virginia creeper vines and other
ornamental plants grown nearby. It is wide-spread throughout
Montana and has caused considerable concern to many gardeners.
The Virginia creeper leaf hopper has been successfully controlled
with DDT sprays and dust.
ROSE CURCULIO (Rhynchites bicolor)
The rose curculio seems to be rather widespread throughout
Montana. Reports of occurrence and injuries from this pest came
from McCone County in 1951, and from Sanders, Roosevelt, and
Lewis and Clark counties in 1952.
LILAC BEETLE (Brachyrinus meridionalis)
Lilac beetle infestations and damage continued to occur at
Hamilton in Ravalli County during the biennium.
CONIFERS
BLUE SPRUCE GALL APHID (Adelges cooleyi)
Unsightly pine-cone-like galling of spruce trees has been ob-
served over most of the state during the biennium. Inquiries were
received only from Yellowstone County in 1951, and from Galla-
tin, Lake, Glacier, and Deer Lodge counties in 1952. Timely spray-
ing with benzene hexachloride has controlled this pest success-
fully.
SPRUCE LEAF-TIER (Epinotia nanana)
Two cases of spruce leaf-tier infestations were reported in
Gallatin and Madison counties in 1951. Only one report from
Roosevelt County was received in 1952. This insect pest of spruce
trees undoubtedly exists more generally throughout the state, but
its damage is either unnoticed or is not reported.
PINE LEAF SCALE (Chionaspis pinifolioe)
Infestations of pine leaf scale were reported in Yellowstone
and Missoula counties in 1951 and in Yellowstone, Beaverhead,
Carbon, Ravalli, Silver Bow, and Gallatin counties in 1952. From
the standpoint of observations it would appear that this pest is
far more prevalent than indicated by these reports.
MONTANA INSECT PESTS, 1951-1952 21
DESTRUCTIVE HOUSEHOLD INSECTS
CLOVER MITES (Bryobia praetiosa)
Clover mites continued to represent a perennial household
pest throughout most of the state during the biennium. The best
treatment currently known is one of prevention by application of
summer oil emulsions or tetraethyl pyrophosphate outside of the
house before the mites make their semi-annual migration into
the dwelling.
CLOTHES MOTHS (Tineidae family)
Clothes moths are a common pest throughout the state. Only
two inquiries were received regarding the control of this insect
during the biennium. It appears that the chlorinated hydrocarbon
insecticides are successfully holding this insect in check.
SILVERFISH (Lepisma saccharina)
No inquiries were received regarding silverfish during the
biennium, though they are known to occur commonly through-
out the state.
DERMESTIDS (Dermestidae family)
Reports or inquiries regarding dermestids were received from
Silver Bow, Toole, Park, and Beaverhead counties in 1951; from
Madison, Yellowstone, Fergus, and Phillips counties in 1952. In
contrast with silverfish and clothes moths, inquiries on dermestids
were far more frequent. Infestations have been observed where
it is doubtful that chlorinated hydrocarbon insecticides would be
effective because they could not be applied to the infested areas.
Cases of this type have been handled with cyanide fumigation.
TERMITES (Isoptera order)
Termite inquiries were received from Beaverhead, Yellow-
stone, Big Horn, Dawson, and Lewis and Clark counties in 1951;
from Lewis and Clark and Yellowstone counties in 1952. Field
observations have indicated certain tendencies of termite infes-
tations in Montana. Extensive damage of the type that is notice-
able and reported is almost always found in the older residential
dwellings usually involving houses built in the late 1800's or early
1900's. In some cases the infestations appear to be intense in local-
ized areas within these older residential districts. These intense
localized infestations sometimes involve only several lots but oc-
casionally involve several blocks.
CEREAL INSECTS (Coleoptra and Lepidoptera orders)
Stored grain insects were prevalent in many parts of Montana
in 1951. This was principally due to the unusually high moisture
content of much of the grain harvested that year. Continued turn-
22 MONTANA EXPERIMENT STATION BULLETIN 484
ing of the grain and fumigation was necessary in many cases.
Treatments with pyrethrum synergist dust were also effective.
In 1952 the grain was harvested in normally good condition and
less difficulties with stored grain pests are anticipated.
Extensive programs were conducted during the second year of
the biennium in cooperation with the Food and Drug Administra-
tion's program of preventing animal contamination of cereal and
cereal products to be used for human consumption. These ex-
tension programs were carried out through regional meetings and
publications of proper methods of handling stored grain.
Frequent inquiries were received regarding the control of
household cereal insects. These infestations are readily eliminat-
ed by destroying the infested cereals, cleaning up the storage
areas, and spraying these areas with either DDT or chlordane.
ANTS (Formacidae family)
Ant infestations which occur generally in and around house-
holds throughout the state are readily controlled with 3 to 5 per-
cent chlordane sprays. Spray application on the outside of the
foundation around the house in the early spring and again in mid-
summer with 5 percent chlordane has been found in most cases
to effectively prevent ant infestations inside of the house through-
out the entire summer.
FLIES (Muscidae family)
There is more evidence, though not conclusive, that resistant
strains of flies are occurring in Montana. Reports of resistant flies
have been received from commercial exterminating companies.
Some of these have been checked and at least in some cases poor
control is the result of normal late season influxes of fly popula-
tions. This was particularly evident in 1952 when a comparatively
long warm fall season was experienced.
COCKROACHES (Blattidae family)
Only a single inquiry regarding cockroaches was received
during the biennium. This inquiry was from Lewis and Clark
County in 1951. Apparently, as is the case with several household
insects, the chlorinated hydrocarbons are doing such a good job
of cockroach control that inquiries are few in spite of the prevalence
of the insect.
BED BUGS (Cimex lectularius)
Three infestations of bed bugs were reported in 1951; these oc-
curred in Blaine, Hill, and Jefferson counties. No reports were re-
ceived during 1952. It is assumed from past experience that bed
bugs are far more prevalent in the state than these reports would
indicate.
MONTANA INSECT PESTS, 1951-1952 23
POWDER POST BEETLES (Coleoptera order)
Two cases of powder post beetle infestations were reported in
Cascade and Flathead counties in 1952. One infestation involved
damage to a wooden desk, the other infestation to woodwork in
a home. These insects were not reported or observed in 1951.
STRAWBERRY ROOT WEEVILS (Brachyrhinus ovatus)
Several cases of strawberry root weevils infesting homes,
particularly basements, have occurred during the biennium. Ap-
parently this insect, which is destructive to strawberries, is not
harmful in the household where it may be seeking shelter. Oc-
currences of this type were reported in Lake and Glacier counties
in 1951, and in Flathead County in 1952.
INSECTS DESTRUCTIVE OF MAN AND ANIMALS
MOSQUITOES (Culicidae family)
Contrary to popular opinion, studies have indicated that the
more important mosquito species present in Montana do not
breed in permanent pools. Instead, these species breed in semi-
permanent standing water which generally accumulates from
three different sources: spring run-off, run-off from rain showers,
and irrigation. Attempts to control mosquitoes by spraying adult
mosquitoes in towns and cities have largely been unsuccessful,
particularly in heavy mosquito areas. It is apparent that if mos-
quito control, under Montana conditions, is to be successful the
mosquitoes must be controlled in their larval stage in the inter-
mittent pools or puddles or such intermittent water must be elim-
inated. More information on the problem is necessary before
large-scale successful mosquito control can be accomplished. An
investigational project was set up in Blaine County in the late
spring of 1952 with the objective of obtaining this fundamental
information. Cooperating in this project are the United States
Public Health Service, the Montana State Board of Health, the
Agricultural Experiment Station at Montana State College, the
people of Blaine County as represented by their mosquito com-
mittee, and the Office of the State Entomologist.
Concurrent with the establishment of the investigational pro-
gram the Junior Chamber of Commerce at Miles City with the
support of the City of Miles City and its citizens decided to at-
tempt mosquito control in hopes of preventing mosquito infesta-
tions within the city during the summer of 1952. This test project
was conducted by 'Mr. John P. Cunningham, the County Sani-
tarian. In so far as possible all intermittent standing water within
about a three-mile radius of Miles City was surveyed frequently
for the presence of mosquito larvae. Whenever mosquito larvae
24 MONTANA EXPERIMENT STATION BULLETIN 484
were found to be present, the water was treated with insecticides.
This control program was successful and Miles City enjoyed a near
mosquito-free summer.
Many additional areas, principally towns and cities, are re-
questing mosquito control programs. In view of the successful
test at Miles City and with more fundamental information being
made available from the investigational work in Blaine County,
it appears that these requests are justifiable. The principal diffi-
culty now confronting such a program is enablement for locali-
ties including towns, cities, and counties to establish and carry out
mosquito control programs.
CATTLE GRUBS (Hypoderma lineatum and Hypoderma bovis)
Since the last printing of this report, Montana State College
Agricultural Experiment Station bulletin 471 (technical) entitled
"Cattle Grubs — Their Biologies, Their Distribution, and Ex-
periments in Their Control" dated December 1950, has been
published. The data presented in this bulletin provide further
evidence that the present known methods of treatment fall far
short of the desired results in bringing about economic control
of cattle grubs. Cattle grubs continue to be an important economic
pest of cattle but treatment in many cases has been discontinued,
due to the practical experiences of many stockmen and the evi-
dence presented from the research mentioned above.
CATTLE LICE (Anoplura and Mallophaga orders)
Cattle lice continued to be one of the more serious insect pests
of cattle during the reporting period. The two sucking species
Haematopinus eurysternus and Linognathus vituli and the one
biting species Bovicola bovis are the only species known to be
present in Montana. It appears that more cattlemen are recogniz-
ing the importance of cattle lice as insect pests to cattle and more
treatment programs are evident. Extensive efforts have been car-
ried out to direct these treatment programs along lines which
would bring about desirable results. These efforts include meet-
ings with stockmen using a silent motion picture film prepared
by the Assistant State Entomologist on the topic of proper spray-
ing for control of cattle lice and the circulation of publications,
newspaper stories, and radio talks.
SHEEP TICKS (Melophagus ovinus)
The sheep tick, which is actually a parasitic fly and not a
tick, is common in all of the sheep-raising areas of the state. Fall
dipping with a rotenone suspension seems to be the most prac-
tical means of combating this problem.
HORN FLIES (Siphona irritans)
A practical demonstration test of the South Dakota type of
MONTANA INSECT PESTS, 1951-1952 25
backrubber was set up near Cascade, Montana, in 1952. This par-
ticular test did not produce satisfactory horn fly. control. It is pos-
sible that more of the backrubbers were needed, or that the brush
in this particular range area competed with the backrubber so
that the cattle were rubbing on the brush far more frequently
than they were on the backrubber. This demonstrational test will
be pursued further in hopes of developing a satisfactory method
of this type under Montana conditions.
The incidence of horn flies appeared to be about normal dur-
ing the biennium except that in 1952 the horn fly season was
somewhat longer than normal due to an abnormally warm fall
period.
MISCELLANEOUS
THE GOAT WEED BEETLE PROGRAM
INITIAL INTRODUCTIONS
Prior to 1951 several introductions of goatweed beetle colonies
had been made into western Montana principally through the
efforts of Mr. James K. Hollaway, Entomologist for the United
States Department of Agriculture, Bureau of Entomology and
Plant Quarantine. Of these several introductions, those that have
been kept under observation were a 1948 planting of Chrysolina
hyperici in the Charlos Heights area of Ravalli County and a 1949
planting of Chrysolina gemellata in the Charlos Heights area of
Ravalli County. Also 1949 plantings of Chrysolina hyperici in
Sanders County on the O. J. Murray Ranch, on the Forest Service
mule pasture just north of Thompson Falls, on the bison range,
and in Flathead County on the north fork of the Flathead River
were observed.
Obeservations through the 1950 growing season yielded little
or no evidence which would indicate that these plantings would
establish themselves strongly enough to provide for redistribution
throughout western Montana and biological control of goatweeds.
The above colonies were introduced under rather adverse
conditions. In each case several days had elapsed between the
time of collection in California and the time of release in Mon-
tana. Consequently, the beetle colonies were in a weakened state
at the time of introduction.
1951 INTRODUCTION
In the winter of 1950 the Western Montana Weed Control
Committee in surveying the goatweed problem found the follow-
ing estimated infestations: Missoula County, 1 acre; Lincoln
County, 40 acres; Flathead County, 60 acres; Mineral County, 420
26 MONTANA EXPERIMENT STATION BULLETIN 484
acres; Ravalli County, 1,615 acres; Lake County, 10,150 acres, and
Sanders County, 141,600 acres with a total of 153,986 acres. As a
result of the survey the Western Montana Weed Control Com-
mittee requested that an organized goatweed beetle introduction
program be carried out as soon as possible. This introduction was
organized by the Office of the State Entomologist and carried out
with the cooperation of the Montana Agricultural Extension
Service, the Agricultural Experiment Station at Montana State
College, the United States Bureau of Entomology and Plant Quar-
antine, the Western Montana Weed Control Committee, the United
States Forest Service, the United States Fish and Wildlife Service,
and others. It was decided to introduce the species Chrysolina
gemellata inasmuch as various investigations indicated that this
species would be more apt to become established under Montana
conditions. Introductions were planned so as to cover as many of
the different ecological habitats in which goatweed occurred in
Montana as was possible. The program was organized in such a
manner as to provide liberation as soon as possible after collec-
tion. The beetles were collected in California by two individuals
hired for that purpose. They were then mailed air express to Mis-
soula, Montana, so as to arrive in the early morning the second
day following collection. At Missoula, Montana, the beetles were
fed goatweed and immediately transported by aircraft to various
points where cooperators would receive the beetles and accom-
plish their release by early afternoon of the same day. A total of 56
colonies of Chrysolina gemellata were introduced with the follow-
ing disposition :
51 colonies in Sanders County 2 colonies in Flathead Count}'
2 colonies in Lake County 1 colony in Gallatin County
The total cost for the operation was $355.86, or approximately
$6.35 per colony.
SURVEY AND REDISTRIBUTION IN 1952
Surveys of beetle release sites were started on May 20, 1952.
In the Charlos Heights area of Ravalli County only three adult
beetles could be found in the 1948 Chrysolina hyperici release
area, and no evidence of beetles could be found in the 1949
Chrysolina gemellata release area. In Sanders County on May 26,
the 1949 Chrysolina hyperici release area on the O. J. Murray
Ranch showed a few adults and numerous larvae. The other 1949
Chrysolina hyperici release area just north of Thompson Falls
showed evidence of considerable feeding, and a few adults but no
larvae were found. Occasional adults and no larvae were found
on several of the 1951 Chrysolina gemellata release areas observed
in Sanders County. The Charlos Heights release area in Ravalli
MONTANA INSECT PESTS, 1951-1952 27
County was reexamined on May 29, 1952, and the Chrysolina
hyperici area showed a few adults and numerous larvae. This
survey indicated the possibility that it was being conducted too
early in the season for observation of adult beetle populations.
A second survey was conducted June 19, through 23, 1952. The
1948 Chrysolina hyperici colony at Charlos Heights showed well
established adult populations as did two 1949 Chrysolina hyperici
colonies in Sanders County. The 1949 Chrysolina gemellata colony
at Charlos Heights in Ravalli County did not show evidence of
establishment. However, the various 1951 Chrysolina gemellata
colonies observed showed good evidence of establishment.
Twelve colonies of adult beetles were redistributed in June
of 1952 from the established 1948 Chrysolina hyperici colony in
Ravalli County, the 1949 Chrysolina hyperici colonies in Sanders
County, and the 1951 Chrysolina gemellata colony in Lake
County. This redistribution program included two colonies
to Mineral County, one colony to Gallatin County, one colony to
Ravalli County, two colonies to Sanders County, four colonies to
Lincoln County, and two colonies to Lake County. In addition,
the United States Fish and Wildlife Service imported seven col-
onies of Chrysolina gemellata from California which were planted
on the Bison Range in Sanders County on May 31 to June 1, 1952.
FUTURE PROGRAM
On the basis of the evidence to date, it appears that many of
the 1951 Chrysolina gemellata colonies will be established and
ready for redistribution in the spring of 1953. It is anticipated that
the larger portion of this redistribution program will be carried
out by individual ranchers. Therefore, an educational program to
be conducted by the Office of the State Entomologist and the
Montana Agricultural Extension Service is being planned. For
this purpose a short 16 mm. motion picture film covering the
mechanics of collection and planting of goatweed beetles has been
prepared by this office. Educational meetings for the purpose of
organizing individual rancher distribution of goatweed beetles are
planned for the spring of 1953.
Some redistribution of goatweed beetles in the spring of 1953
to be carried out by the Office of the State Entomologist is also
planned. Such redistribution will principally involve plantings in
relatively inaccessible areas where goatweed has become
established. These plantings will be conducted by aircraft drop, a
technique which was worked out by the Office of the State Ento-
mologist during the summer of 1952. In addition it is also antici-
pated that the United States Forest Service will conduct some
redistribution programs in 1953.
28 MONTANA EXPERIMENT STATION BULLETIN 484
BIENNIAL REPORT OF THE MONTANA STATE APIARIST
1951 and 1952
During recent years the Montana beekeeping industry has
been undergoing a gradual change. Many small scale and amateur
beekeepers are selling out to larger commercial beekeepers with
a few inexperienced replacements entering the industry. Small
scale operators typically lack the interest necessary for proper
disease and swarm control and many appreciate the opportunity
to sell their operation to a commercial beekeeper. During the bi-
ennium, inspection efforts of the Assistant State Apiarist have
been concentrated on locating and destroying or cleaning out
disease in the smaller apiaries. Such an inspection program was
carried out because it appears that many of these smaller apiaries
act as infection centers for large areas.
The registration of bee locations in accordance with the state
law is necessary so that inspection of all apiaries can be accom-
plished. Many previously unregistered locations have been found
during the biennium and legal registration was accomplished.
The number of colonies inspected annually is limited by the
available personnel. Consequently this report does not show a true
picture of the disease problem of Montana's beekeeping industry.
Many of the larger and presumably disease free or nearly disease
free apiaries have not been inspected or have only been spot
checked. If these larger apiaries could have been included in the
inspections, the percentage of infected colonies would have been
considerably less. The disease problem in Montana is unique in
that much of the disease is harbored in and around rimrocks, old
buildings, and trees which were previously inhabited by diseased
bees. Under these conditions it is doubtful if the disease can ever
be entirely eliminated, particularly in certain areas. The problem
is therefore one of control rather than elimination.
Several western Montana beekeepers have experienced severe
damage to yards located in outlying areas due to the activities of
bears. There is a need for a cooperative program with government
trappers and the issuance of permits for beekeepers to destroy
such bears.
The results of honey bee pollination programs in California,
Utah, and Nebraska have caused considerable interest on the part
of farmers in Montana. Conditions in the aforementioned areas
are widely different from the conditions existing in Montana's
alfalfa and clover seed growing areas. Extensive experimentation
in Alberta and Saskatchewan under conditions more similar to
Montana's indicates that honey bees are of little value for alfalfa
and red clover pollinization and that certain species of wild bees are
MONTANA INSECT PESTS, 1951-1952 29
the principal pollinators. Investigational work along these lines
has been initiated in Montana. However, recommendations cannot
be made until more is known about pollinating activities under
our conditions.
Some areas have experienced considerable difficulties with
damage to bees caused by the application of toxicants for pesti-
ferous insect control. Such has not been the case in Montana prin-
cipally because of cooperation between spray operators and bee-
keepers on proper measures to be taken to prevent bee losses.
During the biennium honey crops have tended to be erratic.
At least one of the reasons for this has been the change in agri-
cultural practices which has eliminated or reduced plants either
permanently or temporarily during critical periods. The honey
crops during both years of the biennium appear to be slightly
below average. The reported state average for the 1951 honey
crop was 72 pounds per colony. The figures are not as yet com-
piled for 1952, but the crop was probably slightly less than in
1951. During both years of the biennium some high and some
low individual honey yields were experienced.
Many areas of the state are overcrowded by bees. This, along
with other circumstances, has brought about a gradual reduction
of the number of registered colonies of bees in Montana. The bee
population has been reduced from about 65,000 colonies registered
in 1948 to 58,719 colonies registered in 1952. The recent increased
price support of honey may tend to level off or even increase the
number of commercial colonies during the next biennium.
30 MONTANA EXPERIMENT STATION BULLETIN 484
Table Of American Foul Brood Incidence In
Colonies Inspected By The Assistant State Apiarist
County Total colonies Colonies No. diseased No.
in county inspected colonies destroyed
Beaverhead 1,606
Bighorn 3,084
Blaine 3,565
Broadwater 1,859
Carbon 2,751
Carter 120
Cascade 1,892
Chouteau 13
Custer 393
Dawson 760
Fallon 58
Fergus 1,679
Flathead 1,617
Gallatin 4,611
Glacier 202
Golden Valley 330
Granite 373
Hill 100
Jefferson 595
Judith Basin 504
Lake 3,517
Lewis & Clark 1,335
Lincoln 60
Madison 3,770
McCone 630
Meagher 350
Mineral 5
Missoula 500
Musselshell 209
Park 2,852
Petroleum 424
Phillips 891
Pondera 1,122
Powder River 767
Powell 144
Prairie 186
Ravalli 2,615
Richland 1,801
Roosevelt 1,119
Rosebud 541
Sanders 925
Silver Bow 7
Stillwater 1,644
Sweetgrass 2,050
Teton 4,523
Treasure 161
Valley 1,470
Yellowstone 1,963
Wheatland 950
TOTAL ~62;643
25
0
0
35
2
2
33
0
0
21
0
0
0
0
0
0
0
0
72
2
0
0
0
0
14
0
0
16
4
4
0
0
0
0
0
0
60
2
0
65
6
6
0
0
0
0
0
0
0
0
0
0
0
0
72
3
0
0
0
0
147
4
4
402
16
3
0
0
0
480
14
1
40
1
0
25
0
0
5
0
0
340
4
4
0
0
0
302
19
12
0
0
0
206
5
0
0
0
0
166
32
32
0
0
0
15
0
0
25
0
0
25
1
0
0
0
0
0
0
0
402
32
28
0
0
0
0
0
0
0
0
0
86
0
0
52
3
3
260
6
0
302
15
12
0
0
0
MONTANA INSECT PESTS, 1951-1952 31
Table Of American Foul Brood Incidence In
Colonies Inspected By The Assistant State Apiarist
County Total colonies Colonies No. diseased No.
in county inspected colonies destroyed
Beaverhead 977 0 0 0
Big Horn 3,365 87 17 17
Blaine 3,575 0 0 0
Broadwater 1,690 26 0 0
Carbon ... 2,493 58 4 4
Carter 124 0 0 0
Cascade 1,874 0 0 0
Chouteau 9 0 0 0
Custer 575 10 0 0
Dawson 838 21 0 0
Fallon 15 0 0 0
Fergus 937 20 0 0
Flathead 966 140 8 2
Gallatin 2,502 136 2 0
Glacier 202 0 0 0
Golden Valley 318 0 0 0
Granite 415 0 0 0
Hill 100 0 0 0
Jefferson 557 119 7 5
Judith Basin 515 0 0 0
Lake 4,302 820 34 29
Lewis and Clark 1,358 45 2 2
Lincoln 10 10 0 0
Madison 2,352 202 35 30
McCone 700 43 0 0
Meagher 350 32 0 0
Mineral .■ 5 5 2 2
Missoula 596 23 3 2
Musselshell 233 25 0 0
Park 2,809 0 0 0
Petroleum 549 186 4 4
Phillips 875 0 0 0
Pondera 711 86 3 3
Powder River 926 8 0 0
Powell 180 0 0 0
Prairie 218 12 0 0
Ravalli 3,408 863 138 138
Richland 2,200 23 0 0
Roosevelt 1,270 46 5 0
Rosebud 683 26 0 0
Sanders 966 200 14 6
Silver Bow 7 0 0 0
Stillwater 1,085 0 0 0
Sweetgrass 1,199 0 0 0
Teton 4,161 105 0 0
Treasure 415 15 0 0
Valley 1,540 308 2 0
Yellowstone 2,511 114 12 12
Wheatland 1,050 56 0 0
TOTAL 58,719 3,870 287 '""256
32 MONTANA EXPERIMENT STATION BULLETIN 484
CONTENTS
INTRODUCTION 3
GENERAL FEEDERS 4
Grasshoppers 4
1951 season 4
1952 season 5
Outlook for 1953 5
OTHER IMPORTANT PESTS 5
Mormon crickets 5
Garden slugs 6
White grubs 6
Army cutworms 6
Pale western cutworms 6
Red-backed cutworms 6
Wireworms 6
Blister beetles 7
Flea beetles 7
Thistle butterfly caterpillars 7
Field crickets 7
European earwigs 8
Spittlebugs 8
Western chinch bugs 8
INSECTS DESTRUCTIVE OF FIELD CROPS 8
Small Grains 8
Crested wheat plant bug 8
Western wheat aphid 9
English grain aphid 9
Wheat stem sawfly 9
Wheat stem maggot 10
Wheat jointworm 10
Grain thrips 1°
A wheat head army worm 10
A wheat leaf sawfly 10
Corn 1
European corn borer 1
Corn earworm 1
Bumble flower beetle 1
Alfalfa and Clover 1
Alfalfa seed chalcid 1
Alalf a weevil 1
Lygus bugs 12
Sweetclover weevil 12
Clover aphid 12
Lesser clover leaf weevil 13
Small milkweed bug 13
MONTANA INSECT PESTS, 1951-1952 33
Potatoes 13
Colorado potato beetle 13
Potato psyllid 13
Sugar Beets 14
Sugar beet root maggot 14
Sugar beet root aphid 14
Beet webworm 14
Spinach carrion beetle 14
Spinach leaf miner 14
Peas and Beans 14
Pea aphid 14
Pea weevil 14
INSECTS DESTRUCTIVE OF GARDEN AND TRUCK CROPS 14
Cruciferae 14
Cabbage maggot 14
Imported cabbageworm 15
Root Crops 15
Onion maggot 15
Onion thrip 15
Asparagus 15
Asparagus beetle 15
INSECTS DESTRUCTIVE OF FRUIT CROPS 15
Orchards 15
Black cherry fruit fly 15
1951 15
1952 15
Rust mite 16
Pear slug 16
Black cherry aphid 16
Codling moth 16
Apple aphid 16
Wooly elm aphid 16
Pear leaf blister mite 17
Small Fruits 17
Millipedes 17
Currant fruit fly 17
Western raspberry fruitworm 17
Raspberry cane borer 17
Strawberry leaf roller 17
INSECTS DESTRUCTIVE OF ORNAMENTALS 17
Deciduous 17
Boxelder bug 1J
Ash borer 17
Green ash aphid 18
Ash flower gall 18
Willow leaf gall 18
Poplar borer 18
Cottonwood leaf-stem gall 18
Vagabond gall 18
34 MONTANA EXPERIMENT STATION BULLETIN 484
Cottonwood leaf beetle 18
Elm leaf curl aphid 18
Spider mites 18
Spring cankerworm 19
A tent caterpillar 19
Cottony maple scale 19
Oystershell scale 19
Birch skeletonizer 19
Cottonwood-leaf miner 19
A leaf roller 19
Carpenterworm 19
Elm sawfly 20
Virginia creeper leaf hopper 20
Rose curculio 20
Lilac beetle 20
Conifers 20
Blue spruce gall aphid 20
Spruce leaf-tier 20
Pine leaf scale 20
DESTRUCTIVE HOUSEHOLD INSECTS 21
Clover mites 21
Clothes moths 21
Silverfish 21
Dermestids 21
Termites 21
Cereal insects 21
Ants 22
Flies 22
Cockroaches 22
Bed bugs 22
Powder post beetles 23
Strawberry root weevils 23
INSECTS DESTRUCTIVE OF MAN AND ANIMALS 23
Mosquitoes 23
Cattle grubs 24
Cattle lice 24
Sheep ticks 24
Horn flies 24
MISCELLANEOUS 25
The Goat Weed Beetle Program 25
Initial introductions 25
1951 introduction 25
Survey and redistribution in 1952 26
Future program 27
BIENNIAL REPORT OF THE MONTANA STATE APIARIST
1951 and 1952 28
Table of American Foul Brood incidence in colonies
Inspected By the Assistant State Apiarist 1951 30
1952 31
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