Montana

Montana
Montana is within:
Country:	United States of America

Back to rangeland portal

Montana is a vast and ecologically diverse state in the northern United States, featuring everything from the Rocky Mountains and forested wilderness in the west to expansive plains and prairie in the east. Its ecosystems support a wide range of wildlife, and its rivers contribute to important watersheds like the Missouri and Yellowstone. Grasshoppers are a recurring concern in Montana’s rangelands, where outbreaks can damage forage and crops, especially during dry, warm summers.

State ecology

Montana is ecologically rich, spanning rugged mountain ranges, dense coniferous forests, high-elevation meadows, and expansive prairie grasslands. The western part of the state is dominated by the Northern Rockies, home to alpine ecosystems and diverse wildlife. In contrast, eastern Montana features rolling plains and sagebrush steppe, providing critical habitat for grassland birds, pronghorn, and native pollinators. The state's rivers and wetlands support migratory birds and key fish species such as trout. Grasshoppers are a recurring issue in Montana’s eastern rangelands, where outbreaks can reduce forage availability and affect agricultural productivity.

Grasshopper populations are typically high in the summer, particularly in Montana’s eastern prairie regions where they frequently damage both rangeland and cropland. Their numbers tend to spike in years with warm, dry spring weather. These conditions promote faster grasshopper development and reduce the spread of natural fungal diseases that would otherwise help keep their populations in check.

There is a remarkable phenomenon in the Beartooth Wilderness where large numbers of grasshoppers or locusts have been preserved in ice for several hundred to possibly thousands of years. Grasshopper Glacier is retreating due to warming temperatures and many of these insects are melting out and disintegrating. This process has provided researchers with the opportunity to identify at least one extinct locust species, the Rocky Mountain locust (Melanoplus spretus). The insects are thought to have been frozen during swarming events when they were caught in sudden blizzards. Similar occurrences have been documented in other grasshopper-containing glaciers across the Rocky Mountains. A female striped grasshopper (Amphitornus coloradus) was taken from Grasshopper Glacier at 9,680 feet.

Highlighted species from Montana

Species	Official common name	Image
Aeoloplides turnbulli	Turnbull’s grasshopper
Aeropedellus clavatus	Club-horned grasshopper
Ageneotettix deorum	White-whiskered grasshopper
Amphitornus coloradus	Striped grasshopper
Anabrus simplex	Mormon cricket
Arphia conspersa	Speckled rangeland grasshopper
Arphia pseudo-nietana	Red-winged grasshopper
Aulocara elliotti	Big-headed grasshopper
Aulocara femoratum	White cross grasshopper
Boopedon nubilum	Ebony grasshopper
Brachystola magna	Plains lubber grasshopper
Bruneria brunnea	Bruner slantfaced grasshopper
Buckellacris nuda	Buckell's timberline grasshopper
Camnula pellucida	Clear-winged grasshopper
Chortophaga viridifasciata	Northern green-striped grasshopper
Cordillacris crenulata	Crenulated winged grasshopper
Cordillacris crenulata	Crenulated winged grasshopper
Cordillacris occipitalis	Western spotted-winged grasshopper
Derotmema haydenii	Hayden's grasshopper
Dissosteira carolina	Carolina grasshopper
Encoptolophus costalis	Dusky grasshopper
Eritettix simplex	Velvet-striped grasshopper
Hadrotettix trifasciatus	Threebanded grasshopper
Hesperotettix viridis	Meadow purple-striped grasshopper
Hypochlora alba	Cudweed grasshopper
Melanoplus alpinus	Alpine grasshopper
Melanoplus angustipennis	Narrow-winged sand grasshopper
Melanoplus bivittatus	Two-striped grasshopper
Melanoplus borealis	Northern grasshopper
Melanoplus bowditchi	Sagebrush grasshopper
Melanoplus bruneri	Bruner spur-throated grasshopper
Melanoplus cinereus	Ashy spur-throat grasshopper
Melanoplus confusus	Pasture grasshopper
Melanoplus dawsoni	Dawson's spur-throat grasshopper
Melanoplus differentialis	Differential grasshopper
Melanoplus differentialis	Differential grasshopper
Melanoplus femurrubrum	Red-legged grasshopper
Melanoplus foedus	Striped sand grasshopper
Melanoplus gladstoni	Gladston grasshopper
Melanoplus infantilis	Little spur-throated grasshopper
Melanoplus keeleri	Keeler grasshopper
Melanoplus kennicottii	Kennicott's spur-throat grasshopper
Melanoplus lakinus	Lakin grasshopper
Melanoplus lanthanus
Melanoplus missoulae
Melanoplus occidentalis	Occidental grasshopper
Melanoplus packardii	Packard grasshopper
Melanoplus picropidzae
Melanoplus rugglesi	Nevada sage grasshopper
Melanoplus sanguinipes	Migratory grasshopper
Mermiria bivittata	Two-striped mermiria grasshopper
Metator pardalinus	Blue-legged grasshopper
Orphulella speciosa	Pasture grasshopper
Phlibostroma quadrimaculatum	Four-spotted grasshopper	File:File:Fld-Phqu2N01-03.jpg
Phoetaliotes nebrascensis	Large-headed grasshopper
Pseudochorthippus curtipennis	Marsh meadow grasshopper
Psoloessa delicatula	Brown-spotted range grasshopper
Spharagemon campestris	Campestral grasshopper
Spharagemon collare	Mottled sand grasshopper
Spharagemon equale	Say's grasshopper
Trachyrhachys kiowa	Kiowa grasshopper
Trimerotropis latifasciata	Broad-banded grasshopper
Trimerotropis pallidipennis	Pallid-winged grasshopper
Trimerotropis pistrinaria	Barren land grasshopper
Xanthippus corallipes	Red-shanked grasshopper

Species of management concern

Grasshoppers have long been an economic concern in Montana. While the state is home to around 70 grasshopper species, only about thirteen are considered economically significant pests. Notable species include the migratory grasshopper (Melanoplus sanguinipes), the clear-winged grasshopper (Camnula pellucida), the two-striped grasshoppers (Melanoplus bivittatus), and the white-whiskered grasshopper (Ageneotettix deorum). These species are commonly found in habitats like stubble fields, roadside ditches, and overgrown pastures, where dry, exposed soil is interspersed with grasses and forbs. Such environments offer ideal conditions for grasshoppers to regulate their body temperature and lay eggs.

Most species overwinter as eggs buried in the top inch of soil. However, some, such as the Speckled rangeland grasshopper (Arphia conspersa), survive the winter as adults but are not considered harmful to agriculture. Grasshoppers begin emerging as nymphs from May through early July, making this a key time for scouting. Since Montana’s pest species overwinter as eggs, the appearance of winged grasshoppers in spring generally indicates non-pest species.

View U.S. Grasshopper Forecast Hazard Maps

Grasshopper management

In 1949, Montana saw its first large-scale grasshopper control efforts using airplanes and newly developed insecticides on rangelands. However, the effectiveness of these operations varied, and the high costs and logistical challenges quickly revealed a gap between the technology’s potential and its practical application. It became clear that a deeper understanding of the biology and behavior of the numerous grasshopper species was necessary. In response, a long-term research program focused on rangeland grasshoppers was initiated that same spring.

Today, the USDA Animal and Plant Health Inspection Service (APHIS) collaborates with landowners to implement control measures, including the application of chemical treatments on rangelands. These efforts are coordinated when outbreaks reach significant levels and are subject to available funding.

Montana State University Extension and the USDA Agricultural Research Service have also hosted workshops to educate producers on grasshopper biology, outbreak predictions, and management strategies.

Grasshopper control can be achieved through biological, chemical, cultural, and mechanical methods, each effective at different times of the year. Biological options include natural enemies like fungi (Nosema locustae), which can be applied in gardens using Nolo Bait. Chemical controls such as Dimilin, Asana XL, and Warrior II are commonly used, with Dimilin being effective early in the season and less harmful to beneficial insects. Cultural practices like early planting, crop and grazing rotations help reduce habitat suitability. Mechanical methods, such as spring or fall tillage, can destroy overwintering eggs, though tillage may reduce soil moisture and lacks a defined cost-benefit threshold.

Featured resource

• 
  Montana.gov grasshopper field guides

Select photos from Montana

No images found for this query—should be coming soon!

Outbreaks

​Montana has experienced significant grasshopper outbreaks historically and in recent years, particularly affecting rangelands and agricultural areas. These outbreaks have been exacerbated by environmental conditions such as drought and favorable breeding habitats.

According to the twenty-sixth report of the State Entomologist, significant damage to grasslands occurred during the late 1870s and early 1880s, reappeared between 1900 and 1904, and was noted again—though to a lesser extent—in the early 1920s. Additional severe outbreaks were reported from 1934 to 1938 and again from 1947 to 1950. Beyond these major events, varying degrees of grasshopper-related damage have been observed in different parts of the state on an almost yearly basis.

In 2021, eastern Montana and western North Dakota faced the second-largest grasshopper outbreak in the past 35 years. Surveys conducted by APHIS indicated that over 20 million acres in the western U.S. were predicted to exceed the economic threshold for grasshopper infestations, with Montana being one of the most affected states.

The 2022 Hazard Map for Montana predicted higher-than-normal grasshopper numbers, particularly in areas with habitats such as stubble fields, ditches, and weedy pastures.

In 2023, the USDA's grasshopper survey pointed to another challenging year for Montana, with continued infestations expected.

Organizations

Organization name	Acronym	Website	Type	Focus	Focus keywords
Montana State University	MSU	https://www.montana.edu	University	Development, Research	Agricultural development, Control, Research, Sustainable development
Montana State University Extension		https://www.montana.edu/extension/	University	Education, Research, Monitoring, Management	Extension
National Grasshopper Management Board	NGMB	https://www.sites.google.com/site/ngmborg/home	Non-profit Organization	Governance, Management	Coordination, Natural sciences
Northern Plains Agricultural Research Laboratory		https://www.ars.usda.gov/plains-area/sidney-mt/northern-plains-agricultural-research-laboratory/	Government	Research, Management
Pest Management Research Unit at the United States Department of Agriculture		https://www.ars.usda.gov/plains-area/sidney-mt/northern-plains-agricultural-research-laboratory/pest-management-research/	Government
Rangeland Grasshopper and Mormon Cricket Suppression Program at the United States Department of Agriculture		https://www.aphis.usda.gov/aphis/ourfocus/planthealth/plant-pest-and-disease-programs/pests-and-diseases/grasshopper-mormon-cricket/ct_grasshopper_mormon_cricket	Government	Management, Education, Information Hub	Control, Forecasting, Monitoring
University of Montana	UMT	https://www.umt.edu/	University	Research	Natural sciences