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Cody – Landowners from around the Cody area gathered on April 4 for a workshop by University of Wyoming Sheridan Research and Extension Center Director Brian Mealor on cheatgrass management, funding and local prevalence.

“For a long time, we thought there was an upper elevation limit, but within the last 10 years, we’ve seen upward expansions and movement into areas cheatgrass hadn’t previously occurred,” said Mealor.


Cheatgrass is primarily a winter annual plant, meaning that its top priority is seed production, said Mealor.

“It doesn’t invest a lot of resources into structure development, but it can get a lot of fibrous roots. It’s really good at taking up moisture from snowmelt,” he explained.

Mealor noted that moisture has a large impact on when cheatgrass will germinate.

“If we get fall moisture, most of the cheatgrass in this area will germinate in the fall,” said Mealor.

According to Mealor, if cheatgrass overwinters, or vernalizes as a seedling, the plant will produce more seeds than if it vernalizes as a seed.

The cold period is critical to cheatgrass reproduction, he commented, explaining, “If it doesn’t vernalize, it doesn’t go through to seed.”

Cheatgrass density also influences seed production of individual plants.

“When it’s really thick, each plant produces fewer seeds per plant, but if we thin it out, they produce more seed per plant, so we end up with pretty consistent seed production,” he continued.


While many landowners think that native perennial biomass declines because of an increase in cheatgrass, Mealor explained that the increase in cheatgrass can be because of increased bare ground, as well.

“It’s a chicken and egg thing. We do know that cheatgrass is highly competitive for moisture in the early spring, which is part of why it becomes such a problem,” he said.

Cheatgrass presence is also able to change landscapes, particularly when looking at the example of changing fire intervals.

“Fire doesn’t always equal cheatgrass, but a high amount of cheatgrass does increase the risk of a fire,” commented Mealor.

He continued, “If we look at traditional historical fire intervals, it is safe to assume we see fires every 40 to 50 years. There are places along the Snake River that burn every three to five years.”

The prolific seed production of cheatgrass is another factor that makes it highly competitive with native species, producing 400 pounds of seed per acre.

“It stays viable in the ground from five to seven years,” commented Mealor. “If we’ve only got 10 percent carry over, that’s still a lot of seed.”


While many treatments exist and the plant itself is not difficult to kill, Mealor stressed, “One treatment is not enough because of seed viability. Biology informs management. There is no silver bullet. It’s a long-term sort of commitment.”

Chemical control is one of the most common and effective methods for both short-term and long-term control.

The most common chemical used is Imazapic, also know as Plateau, which does not having any grazing limitations after application.

Imazapic may also be mixed with glyphosphate, but landowners should be aware that the chemicals will not be selective.

Other chemicals including Matrix, which is available as the off-brand. Laramie, Canter R+P, Landmark EP and Outrider are also available but have differing requirements than Plateau for application rate and grazing.

“It’s open to interpretation, but the way I read the Matrix label, there can be no grazing for one year after application,” he continued.

Mealor noted that a new herbicide called Esplinon that is currently in trials.

“It’s a root growth inhibitor. It doesn’t affect established grasses at all,” he said.

Grazing is another common method that landowners use when managing cheatgrass.

“In some cases it works, but 'work' is relative. The results are a little more subtle,” continued Mealor.

However, grazing can be particularly effective when used in combination with other control methods.

“When we don’t graze, we get a buildup of litter. Cheatgrass emergence and establishment is facilitated by a litter layer,” he said.

A large amount of research is currently being done on utilizing various bacterial and fungal strains as biological control methods, but many concerns about practicality must be addressed.

“At this point, I don’t think we have an adequate biological control method,” noted Mealor.


Several factors should be considered when deciding whether to treat a particular site.

“Timing is important. If the plants gets too big, our treatment is just not going to be effective in killing the cheatgrass,” said Mealor.

Landowners should also consider how much natural recovery potential there is at a site.

“Is there some natural recovery potential on the site? We can get the herbicide to do exactly what we want it to, but there’s just bare ground,” he commented. “Then we’re talking about a restoration project and not a weed control project.”

Mealor continued, “I firmly believe that the best long-term suppression comes from a healthy perennial plant community. If it comes to the point that we need to reseed, we’re not going to have long-term suppression.”

Mealor outlined three key considerations when making decisions at landscape level.

“One, leverage is important. Next, every tool has its limitations and finally, there are some unintended consequences of doing a good thing that we should be prepared for,” said Mealor.

Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

University of Wyoming Extension Specialist of Invasive Plant Ecology Dan Tekiela explained that effective early detection, rapid response (EDRR) involves detection, integrative management and restoration actions.

Early detection

When thinking about the concept of EDRR, Tekiela noted that many people envision a border around the state and when something, such as Medusahead, crosses the border, it’s an EDRR situation.

“That certainly is EDRR,” he commented. “Alternatively, what if we had Medusahead at one specific location in the state and it moves a significant distance?”

Tekiela commented that most people would not consider that movement to be an EDRR situation, but that the strategy is still useful to implement.

“We should be treating it as EDRR just like we would if it had crossed the border from Montana,” he stressed.

According to the Center for Invasive Species and Ecosystem Health, EDRR is defined as action that “increases the likelihood that localized invasive populations will be found.”

Tekiela continued, “We’re talking about that EDRR focuses on populations, not species present in the state as a whole.”


“Another big idea I want to get across is, when we think of management, we’re trying to remove the plant, but when we remove that plant, by nature, we are causing a disturbance,” commented Tekiela.

He noted that most studies suggest that invasive species are benefited by a greater amount of disturbance.

“When we go out there and we’re spraying, we’re causing a disturbance, so it’s trying to find this real fine balance between removing that invader but not causing so much disturbance that we just have new invaders come in,” explained Tekiela.

According to Tekiela, not all management strategies are created equal and should be carefully matched to the circumstance.

“From what we’ve said, it could be summarized, if management equals disturbance and disturbance equals invasion, then management equals invasion,” he said. “That seems ridiculous, and we know that management is important, but there are studies that show the types of management that we choose have an impact.”


“The idea of integrative management is just trying to diversify the types of impacts we impose in that system in a lot of ways, so we’re not impacting very aggressively in one particular way,” explained Tekiela.

An example study that he discussed utilized both grazing and chemical control to more effectively manage Dalmatian toadflax.

“We went out and charted the toadflax cover, cheatgrass cover and perennial grass cover,” Tekiela said.

Based on the project’s timing, most of the other plants were dormant when sheep were moved in to graze, which made Dalmation toadflax more desirable.

“This is one case where we may be able to utilize a timing with the grazing to only get at the species that we care about,” continued Tekiela.


According to Tekiela, the ideas of restoration and management go hand-in-hand.

“We manage in hopes of restoring the area to its native ecosystem,” he explained.

Tekiela continued, “I think a good example of restoration comes from an example where we have 100 percent cheatgrass cover. If we go in and spray it, we make bare ground, and then, if we don’t do anything else, we’ve actually got more cheatgrass and haven’t done anything from a restoration standpoint.”

A strategy that some managers use is to plant a competitive perennial to limit the return of cheatgrass.

“One of the measures that some use is something like planting crested wheatgrass that’s competitive and tends to be better forage, but it’s also not going to be a diverse community, so it shouldn’t be an end for restoration,” he commented.


Tekiela gave an example of a project by Wyoming Game and Fish Department where restoration of land historically dominated by cheatgrass is a priority.

Initially, the cheatgrass was sprayed and then replaced with crested wheatgrass.

“Now, there’s more interest in how to build that diverse community,” said Tekiela. “How can we go from something like crested wheatgrass into a diverse community?”

He noted that it can be beneficial to have an intermediate community, where an assisted succession strategy is used.

“We’re potentially reducing that seed bank because they can’t reproduce in that area, then we can potentially come in with something else that’s more beneficial to the native community,” continued Tekiela.

He concluded, “Some of the benefits of using an intermediate community include potentially reducing herbicide usage and reducing soil erosion. Intermediate communities do all of those things, from a restoration standpoint, that we think of as beneficial.”

Tekiela spoke during the 2016 Wyoming Weed and Pest Council Conference.

Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

Nearly 400 species of grasshoppers are native to the 17 western states. Mormon crickets are closely related insects that are also highly mobile and capable of migrating long distances. In large numbers, they may devour nearly all forage plants in their path.

Bruce Shambaugh is the grasshopper/Mormon cricket national operations manager and state plant health director for Wyoming for the USDA Animal and Plant Health Inspection Service (APHIS) Plant Protection and Quarantine unit (PPQ). He oversees all of the PPQ programs, including grasshoppers, in the state of Wyoming and also manages field operations for the entire grasshopper/Mormon cricket program in the 17 western states.

“There are differences from state to state because of differences in the land where these insects occur, and the people involved in these programs. Each state has evolved their own type of programs, and I try to make these as consistent as possible and still allow flexibility for what they need to do, based on how it has worked for them in their states,” he says.

Pest species

Even though there may be dozens of species of grasshoppers in any given rangeland ecosystem, only a few are considered pests.

Most years, they cause very few problems because there is enough forage for them and for the livestock and wildlife that also use the pastures.

However, these insect populations sometimes reach outbreak levels.

If it’s a dry year and forage is already short, grasshoppers or crickets cause significant damage and economic loss. In these situations, the land management agencies – both federal and state, county and local governments, private groups and/or individual landowners can request assistance from USDA’s Animal and Plant Health Inspection Service (APHIS) to suppress the insect populations.

“Our program goal includes not only suppression treatments but also population surveys so we know where these insects are. We do a nymph survey early in the year, to get field data on numbers of young grasshoppers, to enable us to make management decisions. We also conduct an adult survey later on in the summer and early fall,” says Shambaugh.

“This information goes onto a map to give our best attempt at predicting where to start looking the following spring. We provide this information to all the cooperators, stakeholders, land managers, Game and Fish, landowners, etc., so we can all work together to manage the program for both grasshoppers and Mormon crickets. We try to involve everyone, including private landowners. We all have a common goal to maintain a healthy rangeland ecosystem,” he explains.


Shambaugh notes that not all grasshoppers are detrimental to rangelands.

“Only a handful of grasshopper species are heavy grass-eaters that can occur in densities that could cause significant damage. When we go out on the land to do early spring surveys, our areas of focus are based on what our adult surveys showed us the previous fall. Any information we received through landowner meetings or meetings with cooperators during the year – and reports they’ve given us – is helpful,” he says.

“In the adult survey, we heavily rely on landowners who are out running cattle, doing their ranch work. They can call directly to us or to a county weed and pest district, Extension service or maybe a local land manager who can relay information to us. Perhaps they were out fixing fence or trailing cows and noticed a lot of grasshoppers in certain areas,” says Shambaugh.

Identifying bugs

Shaumbaugh explains that early in the year, grasshoppers can be difficult to spot because the young bugs are less than one-quarter of an inch long.

“This is one of the challenges, to get landowners looking for these young insects early in the spring, at that small size,” he says. “A person often has to get out and walk or get down on hands and knees to look closely at the grass. This is normally not what a rancher is doing. He’s usually in a vehicle or on a 4-wheeler or a horse concentrating on other things.”

Shaumbaugh adds, “It’s a challenge, but the more we know what to look for, it can help to notice whether there are one or two of them hopping or 10 or 20.”

“If the rancher contactsthe State Plant Health Director (USDA-APHIS), then we can come out and do a survey. We respect private land and don’t go across it unless we have permission,” he says.

Addressing the populations

When it looks like there might be an impending grasshopper explosion with a lot of young insects in the spring, timeliness is crucial for suppression efforts.

“This is the largest challenge – to identify a high population quick enough to have time to make any management decisions or suppression treatments, if that’s the first year we know of it,” says Shambaugh.

“Adult surveys in late summer are important to help us identify what might be – or what might lead to – potential problems in the next year or two. If we can do some planning and get interested landowners coming to meetings over the winter, we can do an effective job on suppression treatments the next spring. It is very difficult to do any sort of suppression treatment if that population is just noticed that year,” he explains.

Preferred treatments

The preferred chemical for treatment is an insect growth regulator, so timing is very important.

“It doesn’t have any effect on adult grasshoppers or crickets. The timing window for this treatment is much shorter than for insecticide options. The growth regulator is by far the preferred choice because it is more environmentally friendly and doesn’t adversely affect as many non-targeted species,” he explains.

“In the old days, we wanted to get rid of them all, but that’s not our goal today. These insects are part of the ecosystem and do a lot of good, providing food for other animals and birds,” Shambaugh says.

Suppression is a better goal, keeping numbers to a reasonable level. The earlier a treatment is deployed, the better effect it will have.

On a bad year, with an explosive population of grasshoppers or crickets, knocking them back a bit with this kind of treatment can ensure that they won’t compete so much with the livestock and wildlife that might otherwise be short of feed.

“We should keep our eyes open for young hoppers and then report to our local State Plant Health Director, State Ag Department or local cooperative Extension agent,” he adds.

Heather Smith Thomas is a correspondent for the Wyoming Livestock Roundup. Send comments on this article to This email address is being protected from spambots. You need JavaScript enabled to view it..

According to Scott Votaw, owner of Field Services and Weed Control in Cody, several components must be considered to be successful in bare ground weed control programs.

He defined bare ground weed control, saying “We want treated areas to be vegetation free for an entire year. When I say vegetation free, that means nothing.”


The top priority for bare ground weed control is selecting the correct herbicide, said Votaw.

“Questions we need to ask include, what are the main weeds? Are they grasses, annuals or perennials?” he continued. “All of those are going to require a little something different to control them.”

Illustrating with a fateful story, Votaw stressed that it is important to consider non-target species that are in the area when selecting a chemical.

“What’s going to happen is, many of these things are water soluble, so when it rains, the chemical will go somewhere else we didn’t intend for it to go,” he commented. “I had a guy who sprayed the parking lot at the fairgrounds. At the bottom of the parking lot along the ball fields, they had a whole row of ‘In Memory Of’ rosebushes that are no longer there as a result.”


Proper agitation technique is important for bare ground weed control.

“Most people don’t have the correct equipment. It can get clogged up in the bottom of the tank, or we get it to spray but none of the herbicide comes out because it was all in the bottom,” said Votaw. “We want to make sure that we have constant agitation.”

According to Votaw, adequate coverage is another important factor that applicators should pay attention to.

“We need to get the area covered with a nice, even coverage,” he continued. “If we put out 100 gallons of water to the acre, and we put 90 over there and 10 on the rest of it, that’s not good coverage.”

Droplet size and spread is important for controlling product drift, and Votaw advises that applicators use low-drift nozzles and dye.

“It’s a heck of a lot cheaper to put in dye and know where we’ve been than have to come back later or overlap too much,” he commented.


“Resistance is naturally occurring heritable traits that will survive a herbicide treatment that would naturally kill it,” said Votaw. “Resistance is absolute, no matter how much we put on.”

Votaw explained that there are multiple types of resistance, including cross resistance and multiple resistance.

“Multiple resistance is defined as resistance to more than one mode of action,” he noted. “That’s where we get into a lot of problems.”

Plants are able to develop resistance through a variety of avenues, he explained.

“They can develop resistance through genetic mutation or biotypes. Inside the plant, they can have an altered target site,” continued Votaw. “With enhanced metabolism, we have a plant that can break down the herbicide a lot faster than susceptible plants.”

According to Votaw, many factors can contribute to growing herbicide resistance.

“Some factors that lead to resistance include frequent use of herbicides with the same mode of action, not using any other measure and monoculture cropping systems,” he continued.

Votaw advised, “We need to rotate our herbicides and avoid using the same thing over and over. Limit the application of single herbicide. When possible, we should use tank mixes or sequential applications with different modes of action.”


Votaw noted that it is important to monitor the results of herbicide treatments.

“Typically if it doesn’t work, the customer will call and let us know,” he said.

While failures can occur for other reasons, most treatment failure is due to applicator error.

“It’s almost always the applicator. Almost 75 to 80 percent of the time, it’s applicator error. The rest can be grouped into environmental,” commented Votaw.

It is imperative to be thorough and use the most effective treatment, said Votaw.

“Do it right the first time. The $50 program is not always that cheap if we have to go back and re-treat,” he concluded. “Don’t always use the lowest herbicide rates. That encourages resistance, and if conditions are not ideal, we will have breaks.”

Votaw spoke during the 2016 Wyoming Weed and Pest Council Conference.

Emilee Gibb is editor of Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..

A 2011 study initiated by the Meeteetse Conservation District and USDA Wildlife Services aimed to examine the effect of predators on sage grouse populations within the Bighorn Basin.

“Everyone points the finger at grazing or oil and gas when we look at sage grouse impacts,” says Meeteetse Conservation District Resource Specialist Steffen Cornell. “We know that predation also has an impact.”

By partnering with a variety of groups, including conservation districts, industry people, county predator boards and others, Cornell noted they received ample financial and moral support from the region.


“We contracted with one researcher from the National Wildlife Research Center for the first two years and another for the remaining three years,” Cornell adds. “We’ve just ended the first five years of the study.”

Before concluding the study, the National Wildlife Research Center produced a preliminary report to the Wyoming Natural Resource Trust.

“The preliminary report indicated if we don’t do something about ravens on one of our study sites, the local sage grouse population faces possible eradication in spite of the fact that it has some of the best sage grouse habitat in the Bighorn Basin,” Cornell says.

The National Wildlife Research Center is now finalizing their study results for publishing in a peer-reviewed scientific journal.

Now that their contract with the National Wildlife Research Center has concluded, Cornell explains that they have decided to move forward with additional research.

“We decided we wanted to move on and focus more on ravens,” he continues.

New efforts

Cornell explains that Meeteetse Conservation District, with continued field assistance from Wildlife Services, is moving forward with new research to determine if the impact of ravens can be alleviated.

“Ravens are tremendously successful at whatever they do, and one of those things is seeking sage grouse and depredating nests,” he says. “Since the inception of this project, we’ve secured funding through the Animal Damage Management Board and the Sage Grouse Local Working Group, and we are going to continue to approach those groups as well as others.”

As they continue to seek funding to continue the project, Cornell adds that they are approaching their first field season to look at reducing raven predation.

“We just got a scientific collecting permit on March 9 from Fish and Wildlife Service,” he says. “We will be capturing and radio marking 12 ravens in two locations in Park County.”

Six ravens will be trapped at each study side, along with 10 sage grouse.

“We will split each site into a treatment and control area,” Cornell continues. “On the treatment site, we will be actively locating and removing raven nests. Our permit allows us a quota on the number of eggs and chicks that we can remove.”

While their scientific collecting permit allows the removal of eggs and chicks, Cornell adds that their goal is to remove the nests prior to egg laying to avoid killing chicks, if possible.

Nest removal will occur primarily during the nesting season for sage grouse.

“Nesting pairs of ravens are very territorial,” Cornell explains. “Some research suggests that those nesting pairs are also the specialists when it comes to depredating sage grouse nests.”

“The logic behind our study is that if we can preoccupy the ravens enough that they are constantly trying to rebuild their nests, it would prevent them from having the time to go out and forage for sage grouse eggs,” he says. “We think they will be more worried about producing their own clutches than seeking sage grouse eggs.”

“We are hoping this study sheds some light on other management approaches that are non-lethal and maybe more socially acceptable,” Cornell adds, mentioning that they hope to continue to gather data into 2017.

Hayden Wing and Associates of Laramie, one of the foremost raven and sage grouse experts in the state, has been contracted to assist in the project.

“During our study, coyotes were the number one predators on sage grouse nests,” Cornell says, adding that coyotes more easily managed because of the lack of protection for the species. “We can manage coyotes, and that is being done today. Ravens are protected under the Migratory Bird Treaty Act. It’s much harder to knock their numbers down for the purpose of benefitting sage grouse, but we’re hoping that we see a rise in sage grouse nest success from raven nest removal.”

Raven work

Throughout the state of Wyoming, USDA Wildlife Services State Director Mike Foster says that raven control work is being conducted for health and human safety reasons and to protect livestock.

“We do raven work to protect calves and lambs when they are born,” he says. “This happens all throughout the state when it's necessary.”

Raven control is conducted through the use of an avicide called DRC 1339. The avicide is only available to Wildlife Services.

“This avicide is a very effective product,” Foster says. “We use it on various baits including dog or cat food, which is allowed under a special use permit from the Environmental Protection Agency (EPA).”

When initiating a control activity, Foster explains that Wildlife Services begins by pre-baiting the area of concern. Once the ravens are taking the bait well, the avicide is introduced.

“The avicide affects the kidneys and heart, and the birds experience a quiet and apparently painless death one to three days following ingestion,” he says. “They usually die on their roosts, and there is no risk of secondary toxicity.”

DRC 1339 is generally unstable in the environment and is rapidly metabolized in the target species. Scavengers consuming the dead individuals are not affected. 

“There has never been a known case of secondary poisoning,” says Foster.

“Ravens are protected under the Migratory Bird Treaty Act,” Foster mentions. “Wildlife Services has the permits to allow us to do this work. Private individuals can also get the permits, but DRC 1339 is only available to Wildlife Services.”

Saige Albert is managing editor of the Wyoming Livestock Roundup and can be reached at This email address is being protected from spambots. You need JavaScript enabled to view it..