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Weed ranger crews fight hard against pesky threats

By air, land and water, Weed and Pest rangers combat invasive species.

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Teton County Weed and Pest

The hillside along Game Creek Road was coated in telling brown patches of cheatgrass and purple tinges of knapweed.

Above the plants flew a Teton County Weed and Pest District drone, with eight rapidly rotating rotor blades, steadily coating the noxious weed in a mixture of Milestone and Esplanade herbicides and the “surfactant” that makes it stick.

Weed and Pest Assistant Supervisor Mark Daluge piloted the drone, accompanied by Program Manager Michael Lamere and Supervisor Erika Edmiston.

The district acquired the drone in the spring of 2018, having mulled the purchase for a few years, waiting for prices to drop.

For a land crew it might have taken the whole day to coat the hillside in herbicide. The drone did it in less than 15 minutes.

“It’s a heck of a lot more fun than backpacking, too,” Daluge said.

Teton County Weed and Pest District drone

LEFT: Weed and Pest’s DJI Agras-series drone features a 10-litre liquid tank used for spraying noxious weeds on slopes too steep for staff to hike. CENTER: Teton County Weed and Pest District assistant supervisor Mark Daluge was certified through the Federal Aviation Adminstration to fly the agency's drone. RIGHT: The drone controller features a screen that shows the operator the drone’s location relative to previously mapped areas marked for spraying.

It’s the first time Weed and Pest has used a drone on this particular hill, managed by partner organization Wyoming Game and Fish Department. They’re still largely experimenting with the drone’s capabilities and limits, but it’s in the air approximately once a week.

“We know that this product works being applied by helicopter or by hand, but we want to try it with our drone to see how it works on the hillsides,” Daluge said.

In the long term the goal is to have the drone up in the air every day, targeting hard-to-reach spots with weed killer as well as spraying insecticide in areas where mosquitoes are thick.

Weeds on the hillside present a number of threats. Knapweed and cheatgrass easily outgrow the native sagebrush species, which in turn threatens the habitat of the native sage grouse. Notably, cheatgrass also burns easily, making it harder to combat and contain wildfires.

The drone is the latest tool in Weed and Pest’s arsenal against the threats to local flora and fauna.

Edmiston explained that to target pests and invasive plants, they can’t just look at one part of the problem.

“The most effective ways of treating pests and invasive plants is taking an integrated approach, looking at all the different ways to come at that same problem,” she said.

Teton County Weed and Pest

Daluge holds a large bunch of oxeye daisy removed from an island during his Snake River float. The weed is widespread in Teton County.

“We’re trying to bring in the best tools for the job that are going to make us as effective as possible and efficient. And we’re tweaking it all the time just trying to learn from every summer and do it better.”

Every summer, Weed and Pest hires seasonal workers to lead its field efforts — this year, it had 17 summer hires.

That’s how Edmiston first joined Weed and Pest. It was 2000, she was in college studying elementary education, but she took the job on the crew and relished the opportunity to make a real difference in the landscape.

After she graduated she started working at Weed and Pest full time and hasn’t left since.

By air, land and river

A few weeks ago Daluge and Crew Lead Matthew Prosen boarded the bright yellow Weed and Pest boat at Deadmans Bar and headed down the Snake River to scout for noxious weeds.

Daluge started in Weed and Pest as a seasonal worker in 2004 before rising through the ranks. As a member of the aquatic invasive species subcommittee he’s also heavily involved in the river crews as a float captain.

As Daluge and Prosen stopped on each island to which the GPS system routed them and carefully scoured each location looking for weeds, they came across plenty of lower-priority species like oxeye daisy, scentless chamomile and thistle.

But what was even more notable than what the two men found was what they didn’t — saltcedar and perennial pepperweed.

“In the past this stretch has been a hot spot for saltcedar,” Daluge said.

Saltcedar was originally brought in by order of the federal government in the 1800s with the thought it would control erosion along stream banks. Instead, it outcompeted native species all over the country, monopolizing water consumption and threatening native ecosystems.

In this stretch of the Snake, Daluge explained, it’s likely that visitors with contaminated boats introduced saltcedar unwittingly. The saltcedar competes with the native willows, which serve as the habitat for the native catchfly.

That is why, in addition to fighting the species itself, Weed and Pest has also worked on education initiatives to raise awareness among boat users how to prevent the spread of invasive species.

The Weed and Pest boat crews, which go out on the river several times a week throughout the summer, monitor locations where weeds have been spotted in the past.

Their policy is one of early detection and rapid response.

“An ounce of prevention is worth a pound of cure,” Daluge said.

Teton County Weed and Pest

Mark Daluge and Matthew Prosen search for noxious weeds last month on an island on the Snake River in Grand Teton National Park. Teton County Weed and Pest District has been monitoring known weed sites on islands in the Snake since the early 2000s, and thinks it has done a significant amount of good in the war against weeds.

If the crews remove a weed they will nevertheless check that same spot for the next five years before feeling comfortable proclaiming the weed eliminated.

“It’s important that we check every single point because we never know if plants are going to come back from rootstock,” Daluge said. “Even if we don’t find plants at the points, it doesn’t mean they’re not here.”

Even when a once-weed-ridden spot is no longer checked annually, land crews will still visit it every five years, and new spots will be added if new weed populations are spotted.

It’s a meticulous, time-consuming process that wouldn’t be possible without Weed and Pest’s extensive presence in the field. And its strategy, for the most part, seems to be working.

Daluge said Weed and Pest went from about 1,700 early detection-rapid response points five years ago to about 900 today.

“So, in theory,” he said, “we’ve eradicated almost half of our high-priority weed points.”

Weed and Pest tries to bring its efforts full circle by complementing its prevention and targeted response programs with education.

In her three years at Weed and Pest, Communication and Education Program Coordinator Meta Dittmer has worked closely with schools like Munger Mountain Elementary to bring comprehensive programs to the classroom.

Dittmer will bring education resources like posters and props mimicking weeds to promote awareness of ways to identify and combat invasive species. Students complete research projects on various weeds to cap off the program.

“It’s a really kind of comprehensive thing,” she said. “And the vision is, once we have kids going through all these programs, they’ll come out aware of what we do.”

Putting theory into practice

In addition to being out in the field and the classroom, Teton County Weed and Pest District employees are also fighting pests from the lab.

Amy Girard, the mosquito program coordinator, works closely with Mikenna Smith, the mosquito lab and bio control program manager.

In the lab at the Weed and Pest headquarters a table is strewn with insect display cases Smith has been creating. The cases are in varied stages of completion, with moths, butterflies and beetles stacked and labeled like paintings on a museum wall.

When the work is finished the cases can be used as educational tools or moved downstairs to the entrance lobby so homeowners can compare the samples to species they find in their own backyards.

Smith, who working toward a second master’s degree in entomology, funded by Weed and Pest to complement her master’s in agricultural science, also runs the lab’s insectary.

She and Girard colonize species to have pesticide-resistant qualities, in order to be able to predict how the species in the wild will react to regular insecticide application.

“Ideally, every district that is putting out pesticide should be testing for it, but a lot of districts don’t,” Smith said. “Pesticide resistance is quite prevalent globally. If you are applying at a regular interval and without doing prior surveillance, you can create conditions that are more conducive to resistance.”

It’s one of several ways — combined with targeting larvae populations and using adult insecticide sparingly — that the mosquito program emphasize prevention.

Teton County Weed and Pest District drone

Teton County Weed and Pest District Program Manager Michael Lamere prepares to fill the agency’s DJI Agras-series drone with spray chemicals. Weed and Pest employees recently started using the drone, specially designed for agriculture work, to spray noxious weeds and mosquitoes.

The mosquito program also plays an important role in disease surveillance. Local mosquito species like Culex tarsalis are known West Nile virus carriers, so Smith and Girard frequently collect samples of the mosquito in the field to test back in the lab.

“We’re essentially out there every day looking and treating and doing surveillance, everything we can to offer protection to our residents and visitors,” Girard said. “We can’t take all the credit for every mosquito, but we are there every single day throughout the summer doing what we can.”

The work the weed rangers do out in the field also changes the way they interact with the landscape. Once you’re trained to spot every weed and pest in the area, it’s harder to casually enjoy time outdoors without thinking of every threat to the ecosystem.

But it remains rewarding work for those who dedicate themselves to it.

“I feel like we’re protecting this watershed and this whole valley for generations to come by doing the work that we do,” Daluge said. “And it’s satisfying because over time you can see things improve.

“I’d love to lose my job because the weeds are all gone — but I don’t think I’ll be that lucky.”

Contact Leonor Grave by emailing

(1) comment

Thurs Darp

Thank you Weed Rangers for your service!!

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