Montana Urban Alerts

The invasive brown marmorated stink bug, Halyamorpha halys, was confirmed for the first time in Montana on January 26th, 2021 (from inside a home in Billings).

We currently don't know if it is established in Montana and what impact it might have on our crops and specialty crops across the state.

Its detection in other states poses problems ranging from a nuisance to a severe agricultural pest.


  • Brown marmorated stink bugs have stylet's, which pierce into the fruit, pods, buds, leaves, and stems of several plants.

Preferred Hosts:

  • Yard and Garden
    • Some preferred hosts in the yard and garden include catalpa, sunflower, crab apple, apple, cherry, and other Prunus species.
  • Crops
    • Corn is a favored host
  • Specialty Crops
    • Apples, pears (Asian and European), grapes, peaches, sweet corn, pepoers, Swiss chard, and tomatoes.

What We Know about Brown Marmorated Stink Bugs

  • Wide host range
  • Damaging pestof apples, grapes, cherries, and several other Prunus species
  • It is a serious pest of ecnomic importance for tree fruits in the mid-Atlantic states and has caused more than $37 million worth of damage (report as of 2010).
  • Itis detection in other states poses problems ranging from a nuisance to a severe agricultural pest.
  • Invades homes in the fall (nuisance pest)
  • Harmless to humans

What We Don't Know About BMSM in Montana

  • If it is established in Montana (if reproductive populations exist in Billings and other areas of te state)
  • What hosts might it impact and whether it will be a pest of ecomonic importance for crops and specialty crops.

Monitoring and Management:

  • Several cooperating state and federal agencies have been monitoring for BMSB for several years in Montana.
  • Monitoring efforts will continue with a focus in the Billings area.
  • Please send suspected specimens and/or detailed photos to your local extension agent or samples can be submitted to the Schutter Diagnostic Lab by following directions at
    • There are several look-alike bugs



Blister beetles are leaf-feeding insects that secrete a liquid that can cause blisters, and can be toxic when accidentally fed to livestock in forage. Of nine species observed in Montana, only one has been reported to have damaged crops.

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Adult Alfalfa weevils are snout beetles approximately 3/16 inch long. They are light brown with a dark brown stripe from the head to about three-quarters down the back, narrowing as it progresses down the back. Older weevils may have a less distinct stripe. In colder regions where adults do not become active until spring, over wintering is thought to occur outside alfalfa fields. In warmer regions where adults are active during the winter months, overwintering is thought to occur within alfalfa fields. When temperatures warm to about 48 degrees F in the spring, the weevils become active.

Click here to read more on alfalfa weevils!

Montana and the surrounding region are currently observing large numbers of "miller" moths congregating near buildings at night where they are attracted to sources of light. Any type of moth that is abundant around homes have been called Miller Moths. In Montana and surrounding states it is typically the adult stage of the army cutworm. Euxoa auxiliaris.

The larval caterpiller stage feeds on a variety of plants and crops during the spring season, and now in early summer the emerging adult stage migrates from the plains to higher elevations in mountains.

Later in August and September the moths return to the plains to mate and lay eggs.

Want to read the full MontGuide? Click here!

Watch for false chinch bugs in mustards and canola, as they are reportedly causing damage to mustards in several Montana locations. They feed on plant sap with strawlike mouthparts.

In high numbers false cinch bugs can cause significant wilt and dieback.

Physical apperance and life cycle

Management Approches in Wheat

Problems in Urban Landscaping

There are several viruses of wheat and barley in Montana that can be economically important. Here we describe the symptoms and control for these diseases.



June 8th, 2020

Wireworms are reported in high numbers in small grains across much of Montana. Wireworms are the soil-dwelling larvae of click beetles.

Wireworms cause damage to the seeds, roots, tubers, and bulbs of various crops.

They are worm-like larve up to one inch in length, with a hardened exoskeleton and variable color depending on species, from whitish to orange.

Wet Soil Conditions Favorable for Wireworms

Grasshoppers in Yards and Gardens

Grasshopper outbreaks are occurring in several areas in Montana. They are difficult to control due to thier migratory nature and voracious feeding on several host plants. They tend to avoid feeding on trees and large shrubs unles outbreaks are heavy.

Most grassshoppers overwinter in the egg state in the soil. After egg hatch in mid to late spring, the nymphs immediately begin feeding. There are at least 5 or 6 stages of nymphs before the grasshoppers reach adulthood. The adult grasshopper can live several months into late summer/early fall.


Pear Slugs

Pear slugs chew the leave of many common trees and shrubs such as Cotoneaster, Cherry, and other related plants.

Pear slugs are not true slugs. They are a type of insect known as sawflies.

Two generations of pear slug occur. Most damage usually occurs from the second (September) generation.

When severe defoliation is threatened, pear slug injury should be controlled.

More on Pear Slugs

Blister Mites on Apple Trees

They prefer to host on Apple, Crab Apple, and Pear trees.

The mites overwinter as adults beneath bud scales. When the buds start to grow in the spring, mites attack the emerging leaves. Their activity increases in teh summer with two-three generations per year.

More info

Alfalfa blotch leafminer is a European pest that was accidentally introduced to the northeastern U.S. in the late 1960's. Since then, it has spread westward across the northern U.S. and through the maritime and prairie provinces of Canada.

This insect has been present in Wisconsin and Minnesota since the mid-1980's.

Read the full article

Honeylocusts have been looking thing, showing brown tips, and defoliating. This is likely due to the honeylocust pdogall midge. These are common every year, but damage from the pest is more evident this year.

More info on Damage, Scouting, and Management, click here!

Montana has several home-invading weevils that come into our homes in April through November.

They are harmless to humans and structures.

More info

Cydia pomonella

Codling Moth is a major pest of apple, pear, and walnut trees in North America.

In Montana, moths emerge from pupae in spring, mate, and lay eggs. Larvae hatch, burrow into fruit, and feed on the developing seeds. Mature larvae exit fruit, travel down the trunks of trees to spin cocoons and either overwinter or pupate after a few weeks to produce a second generation of moths in late summer.


Managing Codling Moth in Montana Commercial Orchards

Managing Codling Moth in Montana Home Orchards

Montana Codlng Moth Trap-Based Biofix Compared to Two Fixed Biofix Models

Montana Surveys of Codling Moth Damage to Apple Fruit

The White Pine Weevil which kills the tops of conifers, is the most serious ecomonic insect pest of white pine in Maine. Weevil attacks result in trees that are multitopped, crooked, and of much lower value for sawtimber.

Appearance and development of ornamental trees are also affected. Trees in open areas, plantations, and forest clearings are most severly damaged.

White Pine Weevil most commonly attacks Eastern White Pine, Jack Pine, and Norway spruce.

However, many other pines and spruces, including ornamentals, are also susceptible.

Finish Reading Article

The most common ticks in Montana are the Rocky Mountain Wood Tick, Dermacentor Andersoni, and the American Dog Tick, Dermacentor variabilis. The two species look very similar.

We no longer have either of the two species of black-legged ticks (formerly deer ticks) that vector Lyme disease in Montana.

The Rocky Mountain Wood Tick transmits Rocky Mountain Spotted Fever and Colorado Tick Fever. RMSF transmission is rare in our state.

Read more about Diseases, Prevention, and Removal

More articles

Ticks of Veterinary and Public Health Importance in Montana

Diseases Vectored by Ticks

Information from CDC

Homeowners and producers enduring occasional pest outbreaks often over-rely on chemical management strategies or react after pests can be managed effectively.

Pest management using multiple methods, otherwise known as Integrated Pest Management (IPM), is a strategy combining a wide range of tactics, including biological, chemical and cultrual practices to provide long term, environmentally sustainable, and economically feasible control.

Pest Resistance

Pesticides became increasingly ineffective at managing many pests due to overuse. Pest resistance is defined as the ability of a pest to tolerate a pesticide that once controlled it.

Resistance takes place due to repeated pesticide applications using one chemical mode of action, thus selecting for survivors with an inherent genetic advantage to the chemical applied.

Resistance: The ability of a pest to tolerate a pesticide that once controlled it.

Loss of Beneficial Organisms

The overuse of broad - spectrum insecticides negatively impacts many beneficial arthropod species.

Beneficial species are often referred to as "natural enemies". There are various parasites, predators, and pathogens that reduce pest populations.

The use of broad - spectrum insecticides may decrease the survival of many natural enemies, thus causing a second pest outbreak, or a resurgence of the original pest.

Persistent Pesticides Impacting Non-Target Sites

Even though pesticide applications may not impact non-target sites initially; persistent chemistries may eventually move to non-target areas. Non-target injury may include losses to future susceptible crops, water contamination through movement via leaching or runoff, or bio-accumulation, or bio-magnification in the environment.

More included information:

  • Integrated Pest Management
    • Biological control
    • Chemical control
    • Cultural control
    • Genetic control
    • Mechanical control
    • Regulatory control
  • Implementing an IPM Program

Read full MontGuide


Tanacetum vulgare

Common tansy has a long history of medicinal use but has become a problem weed in pastures and along roadsides, fence lines, and stream banks.

Also known as golden buttons and garden tansy.

Is a perrenial herb in the sunflower family.

The plants contain alkaloids that are toxic to both humans and livestock if consumed in large quantaties.

Cases of livestock poisoning are rare, though, because tansy is unpalatable to grazing animals.

Common Tansy info

Waterhemp is a very problematic weed that causes extreme yield losses in crop fields in other parts of the United States and Canada.

Waterhemp is widespread in cropping systems in the Midwest.

Has recently been documented in Montana

Water Hemp Info

Ventenata is a winter annual grass native to Southern Europe, Western Asia, and Northern Africa. It is also known as wiregrass or North Africa grass.

Ventenata is typically 6 to 27 inches tall with leaves that are rolled lengthways or folded.

It has open sheaths, and the inflorescence is more or less lax, open, and pyramidal in shape.

The color of ventenata has been described as tawny to light yellow.

Lives in roadsides, hay, pastures, range, CRP fields in the Western U.S.

Check out this 60-second video on key features of what to look for!

Identifying Ventenata Early in Summer

There are studies being done right now for a potential Biocontrol Agent for Canada Thistle

The research is just beginning to assess how well the rust reduces Canada thistle patches.

Informational Documents:

Montana Biological Weed Control Coordination Project

Reach Out to Us

Send your samples to the Schutter Diagnostic Lab

Preventing Palmer amaranth from establishing and becoming a troublesome weed in Montana is a high priority.

Palmer amaranth is a problematic broadleaf weed in the pigweed genus. Pigweeds are common in agricultural fields around the world. Pigweeds are warm season annual plants that grow quickly and aggressively, compete with crops, and reproduce through prolific seed production.

While Palmer amaranth has not been found in Montana, a number of pigweeds are weedy here, including redroot pigweed (A. retroflexus), mat pigweed (A. blitoides) abd tumble pigweed (A. albus). Of the three, red root pigweed is the most common in croplands.

Palmer amaranth has characteristics that make it more problematic than other pigweeds, including rapid growth, prolific seed production with hundreds of thousands of seeds per plant, and resistance to multiple herbicide modes of action.

It was ranked as the most problematic weed in the United States in 2016 and has had enormous economic impacts in southern states.

Palmer amaranth continues to expand its range, causing major yield losses in a variety of crops.


Seedings and Vegetative Characteristics

Distinguishing among pigweed plants can be difficult before they produce flowers. Palmer amaranth's stem is reddish and smooth with no hairs.

Palmer amaranth leaves are alternate and grow symmetrically around the stem like most pigweeds. Leaves tend to be more elliptical (egg-shaped).


Palmer amaranth is dioecious, meaning there are seperate male and female plants. The long flowering stems of female Palmer amaranth plants make the distinct from redroot pigweed.

The male and female inflorescence is terminal, meaning it occurs at the end of the stem, and is usually very elongated. Spiny bracts surround the female flowers and flower clusters are spinier to the touch than redroot pigweed. The female inflorescence is generally thicker than the male inflorescence and can be easily identified by rubbing it.

Read full MontGuide

Pesticide Info

Measures annouced by the U.S. Environmental Protection Agency (EPA) are in place regarding the herbacide active ingredient paraquat (i.e. dichloride salt of paraquat, ortho paraquat CL, paraquat dichloride) due to increased human health concerns.

Finishing reading article

Rejuvra is a pre-emergent herbacide used for control of annual grasses like cheatgrass, Japanese brome, ventenata, and medusahead.

Rejuvra reduces emergence of seedlings though inhibition of cellulose biosynthesis.

For best results, it should be applied prior to seed germination, and it requires moisture within several weeks of the application.

Read full article!

Crop Diseases

Ascochyta blight of chickpea is highly prevalent statewide in Chickpea.

We have also found Botrytis and significant root rot issues.

Read more about crop diseases!

Crown Rust or leaf rust of oats is caused by the fungus Puccinia coronata var, avenae.

Crown Rust infects the Illinois oat crop almost every year.

Several specialized varieties of the fungus attack many related grasses.

The amount and severity of infection varies greatly from year to year, depending on weather conditions, the amount of rust inoculum ( spores ) present, and the acreage of susceptible varieties.

Other articles to check out about Crown Rust

University of Minnesota Cereal Rust Lab

US Scab Initiative

Top Crop Manager

Prevention Article

Stripe rust can occur anywhere in the U.S. and Canada, causing substantial yield losses when conditions are favorable.

Stripe Rust is caused by Puccinia striiformis and is also known as yellow rust.


  • Starts as yellowish flecks on leaves.
  • On sesceptible varieties, pustules containing yellow-orange spores erupt from leaves.
  • Pustules are clustered on seedling leaves, while pustules on mature leaves occur in a linear, stripe-like pattern.
  • Later in season, yellow-orange fungal spores turn black and remain attached to a leaf tissue.

Stripe Rust pustules form a noticeable striped pattern on mature leaves and are more yellow than stem rust spores.

Check out these articles for even more information:

Stem, Leaf, and Stripe Rust Resistance in Wheat

Stripe Rust of Wheat

Fusarium head blight is a disease of wheat and barley.

The pathogen reduces yield, seed quality, and produces a vomitoxin called DON.

The primary symptom of the disease is bleaching of some of the florets in the head before maturity.

Severe infections can cause premature blight or bleaching of the entire spike or head.

Read more with these articles!

US Wheat and Barley Scab Initiative

NDSU Guide


Pulse Crops are annual dry grain legume crops that help fix atmospheric nitrogen, they are drought and heat tolerant, and have a positve impact on the yield of subsequent crops through the changes in soil.

The main pulse crops produced in the Northern Great Plains are field pea, lentil, dry bean, chickpea, faba bea, and lupine.

The Root Rot disease complex of pulse crops causes damping-off, seeding, blight, root rot, and reduces stand establishment, nitrogen fixation, root distribution, and root vigor.

Uneven planting caused by poor germination and seedling blight are also results from Root Rot.

If you are wanting even more information or are worried about Root Rot in your fields, please contact Mary Burrows at; 406-599-9966; @MontanaCropDoc

There are several viruses of wheat and barley in Montana that can economically important.

Wheat Streak Mosaic Virus

  • occures in all wheat-growing regions worldwide and can infect winter and spring wheat, durum, barley, corn, and many other grass species.
  • Symptoms are yellowing of the leaf in a streaked or stippled pattern.
  • Severely infected seedlig plants may appear lemon yellow and can be confused with nutrient deficiency or cold damage.

Wheat Curl Mite

  • Another common mite on wheat
  • Not easily seen with the naked eye, but when present in high numbers can make the wheat leaf curl so that the upper surface is rolled inward.
  • Small white, cigar-shaped mite

Links with more info!



Ascochyta blight is a rapidly spreading disease that is favored by cool, wet conditions.

Because the disease can spread very rapidly, producers should spray crops twice. Once at the first sign of the disease.

Early symptoms are circular lesions with black specks that are visible with a magnifying glass.

Lesions appear on leaves and stems. Stem girdling and breakage can also be present.

Articles on Ascochyta

Extension Plant Pathology Website

Ascochyta Blight in Chickpea

Fungicide Table


Fungicides have become an essential tool for growing high yielding, top-quality crops in Saskatchewan.

However, with increased fungicide use year after year, resistance (insensitivity) within some of the main pulse crop diseases has begun to emerge.

Awareness of potential insensitivity issues, in-depth understanding of fungicide groups, proper fungicide use and rotation, and integrated disease management strategies are required in order to delay further development of fungicide insensitivity.

Fungicide Insensitivity in Pulse Crops

With the recent weather, disease conditions are very conductive on all crops.

Katie H likes to say "high yields potential means high disease potential" and it isn't a lie!

Here are a few tools to aid in fungicide decision making:

Fungicide Use in Field Crops: Benefits and Risks

Foliar Fungicides for use in Pulses

Foliar Fungicides for Use in Wheat

Fungicide Decision Tool

YouTube Video

**Remember that pea and lentil do get a disease called Ascochyta Blight but the pathogens are different on each host and do not infect other crops.

Recommened Fungicides

Dr. Michael Wunsch results

Other Interesting Articles

"Montana's Real Treasure"

Growing Lentils organically can improve our soil and increase producer incomes.

Lentils are good food - satisfying, nutritious, and delicious!

Lentils are high in fiber, essential nutrients, and phytochemicals.

Eating lentils can improve our health and prevent chronic diseases like heart disease, diabetes, and cancer.

Cooking with lentils is simple and inexpensive.

Observation from the Road: Lentils

Get Ready to Scout for Cutworms

Wet Soil Conditions Favorable for Wireworms

Visit this website for more information:

Soil Testing

or Contact

Monica Brelsford

Carmen Murphy

Mary Burrows

Environmental stress in trees can be present in many ways:

  • Changes in the tree canopy
  • Early onset fall coloration
  • Interveinal chorosis of varying degrees.

These symptoms can also indicate potential pests adn pathogens, so it is important to rule those out before managing for chlorosis.

To read more about Tree Stress symptoms and management click this link:

Stressed Trees

How to know if yuor garden has been injured by herbicides:

  • You may see extreme cupping and twisting of leaves
  • Twisting and/or cracking of stems
  • General distortion of plant leaves
  • Leaves may feel thicker than normal
  • May have veins that look more parallel than usual

Commonly these symptoms can come from other sources including:

  • Herbacide drift
  • Insect or disease issues ( if symptoms are not widespread)

Our recommendation is to never injest produce that has herbicide injury symptoms. Especially if you are unsure of the herbicide that is responsible.

Additional Resources:

Understanding Herbicide Contaminated Soil Amendments for Greenhouses, Nurseries, and Home Gardens

How to Prevent Non-Target Injury of Broadleaf Crops

Minimizing Pesticide Contaminated Soil Around the Home and Garden

Fairy Rings are dark green areas of grass or turf that form a circular or semi-circular pattern, orccasionally, with areas of slow-growing or dead turf.

Mushrooms can form in the dark green rings.

Fairy rings range from 3ft to over 100 ft in diameter.

Fair rings in lawns are usually formed by the fungus, Marasmius ordeades, referred to as the fairy ring mushroom.

Fairy rings are formed by fungi that live in the soil and break down dead, organic matter.

Read more on Fairy Rings.

Master Gardener Q & A

Fire Blight is a bacterial pathgen that infects flowers of pear, apple, and other members of the Rosaceae family.

Symptoms include dead branches, water-soaked blossoms, light brown to blackened leaves, discolored bark, black "Shepherd's Cook" twigs.

The development of the shoot blight is dependent upon the existence of wounds at the shoot tips and the dissemination of the fire blight pathogen to those tips.

The initial symptom of shoot infection is flagging or wilting of the shoot tips.

The bacteria can rapidly spread through the plant killing both the scion and rootstock of susceptible cultivars and rootstocks.

Young trees are particularly vulnerable to the disease which thrives under warm and humid conditions.

Fire Blight 2020

Tool to Assess Your Fire Blight Risk

After an early cold snap, give trees time to recover.

A good way to see if your tree is still alive is to use your fingernail to shallowly scrape into the cambium of the branch. If it still green, the branch is still alive and just needs time to recover.

Read Full Article

How to Help Plants Prepare for Winter

We have several social wasps in Montana.

Except for the Western Yellowjacket, social wasps are typically not aggressive unless their nest is disturbed.

Most common wasps are bald-faced hornets, aerial yellowjackets, Western Yellowjackets, and paper wasps.

They live in colonies, which include workers, queens, and drones.

They all feed on insects.

Wasp nests are abandoned in late summer, and only the fertilized females will overwinter. All the workers and drones die.

More on Wasps

Asian Giant Hornet is the largest hornet species in the world and ranges from 1.5" to 2" long and can be distinguished from other similar species by their large size and yellow-orange head.

AGT only nest in the ground, unlike other species of wasps and bees.

AGH feed on other insects for food and do not ususally attack humans unless provoked.

They have been known to target honey bee hives, particularly in July - November.

Murder Hornets... Fact or Fiction?

Report Sightings to the Montana Department of Agriculture