How bugs, fungi, and herbicides keep Oregon’s noxious weeds at bay > Oregon

Retired Gilliam County Noxious Weed Chief Don Farrar searches for invasive toadflax in 30 Mile Canyon in September 2022.

Retired Gilliam County Noxious Weed Chief Don Farrar searches for invasive toadflax in 30 Mile Canyon in September 2022.

Kristian Foden-Vencil / OPB

Tackling weed growth in Oregon is like painting California’s Golden Gate Bridge—it’s a never-ending job.

And no – not that kind of weed. While cannabis sales bring in money for the state coffers, invasive weeds like toadflax, medusa head, and cheatgrass cost Oregon more than $80 million a year. They suffocate native species and are not good fodder for animals.

If these weeds were left to their own devices, losses would total $1.8 billion, according to the Oregon Department of Agriculture.

In the 1970s and 1980s, Oregon’s farmlands were ravaged by a nasty new weed called tansy ragwort. When cattle and horses have eaten enough, ragwort alkaloids cause liver damage and death.

To save its dying livestock, Oregon has launched a new noxious weed program

Since then, people like Don Farrar, 66, have spent their careers finding and eradicating harmful weeds. The lifelong rancher has just retired as head of Gilliam County’s noxious weed program. To give a sense of the scope of his department’s work, he explained what it took to control just one of the 130 weeds on Oregon’s list of noxious plants.

Don Farrar uses a bug catcher to catch bugs so they can be placed on weeds elsewhere.  Sep 2022

Don Farrar uses a bug catcher to catch bugs so they can be placed on weeds elsewhere. Sep 2022

Kristian Foden-Vencil / OPB

“Toadflax had been here for years,” he said, leaning over his pickup truck in Condon on a dry September day, “it just gradually took over and got worse and worse. Farmers used harsher chemicals to try to control it. And they didn’t really keep up. And neither do we.”

Dalmatian toadflax was first noticed in Oregon in the early 1900s. It is believed to have originated in the ballast of ships from Europe. The peasants started simply pulling it up by the roots. But this is exhausting and relatively ineffective. After World War II, herbicides were widely used. The problem was that they were raw and killed all types of plants, not just toadflax.

Over time, however, herbicides became more concentrated, and Farrar recalls spending $100,000 to rent a helicopter for a week to spray Gilliam County’s steep canyons. The herbicides worked well enough, but environmental laws meant they couldn’t spray within 50 feet of a creek. So toadflax has simply settled along the waterways, sending out untold millions of seeds each season.

“We would never get that,” Farrar said.

Mecinus beetles burrow into Dalmatian toadflax to lay their eggs.  Sep 2022

Mecinus beetles burrow into Dalmatian toadflax to lay their eggs. Sep 2022

Kristian Foden-Vencil / OPB

Then, in the 2000s, he found a technical journal that suggested killing it with a bug from Europe. The beetle is called Mecinus janthinus and it burrows into the stem of toadflax — and only toadflax — to lay eggs for its larvae.

But there was a problem. A bug costs $500. And they were hard to find.

“They were new and there was no one who actually had them,” he said.

Nonetheless, with a $50,000 grant from the Oregon Department of Agriculture, Farrar purchased 100 Beetles from an Idaho supplier. Trouble was, putting $500 bugs out in the open and letting the state know their whereabouts pretty much guaranteed the expensive critters would be poached.

“It was disappointing that once we got established, vendors would come in and take something,” Farrar said.

Mecinus janthinus beetles were introduced to control toadflax blooms.

Mecinus janthinus beetles were introduced to control toadflax blooms.

Kristian Foden-Vencil / OPB

He decided to give the state only one spot for insect placement—along 30 Mile Canyon. He kept the other spot on the John Day River for himself.

And it worked. The beetles devoured most of the toadflax along both rivers, leaving native species alone.

Well, says Farrar, when toadflax booms—as it does every now and then—there is a subsequent boom in the mecinus beetle population, which naturally brings toadflax under control again.

On this September day, Farrar gazed up 30 Mile Canyon into a sea of ​​native sage bunchgrass and delphiniums. He thinks it’s a good idea to just keep the site a secret for a while.

“Within the next few years, we had enough[bugs]for just about anyone in the state who wanted them,” he said.

So this is a cannabis success story. But Oregon’s Noxious Weed Program has also faced challenges in recent years. For one thing, the serious young people like Farrar who signed up for a career with the agency in the ’70s and ’80s are now of retirement age.

“I said to the leaders of this agency three years ago that at that point we had 57 people who could retire,” said Lauren Henderson, interim director of the Oregon Department of Agriculture. “It happens.”

“I said to the heads of this agency three years ago that at that point we had 57 people who could retire.  It's happening,

“I said to the heads of this agency three years ago that at that point we had 57 people who could retire. It’s happening,” said Lauren Henderson, interim director of the Department of Agriculture.

Kristian Foden-Vencil / OPB

Along with all the retirements, funding has become an issue. The program is largely paid for by the state lottery. But the cafes and bars that have lottery machines just weren’t open during the pandemic, leaving little money.

Henderson said he must either fire everyone in the weed program or have them work elsewhere.

So, during COVID, the state’s weed experts shifted gears and worked on a different kind of weed — cannabis.

The state wanted to make sure that Oregon hemp farmers wouldn’t grow cannabis containing the hallucinogenic compound THC unless they were licensed to do so.

But Henderson says his staff have now stopped focusing on weed, the drug, and are once again fighting weed, the invasive plant.

Oregon Department of Agriculture entomologist Joel Price is one of the younger employees.  He's pushing the boundaries of weed control to include pathogens - so he uses things like fungal and nematode worms and beetles.  Sep 2022

Oregon Department of Agriculture entomologist Joel Price is one of the younger employees. He’s pushing the boundaries of weed control to include pathogens – so he uses things like fungal and nematode worms and beetles. Sep 2022

Kristian Foden-Vencil / OPB

And not all Beetle enthusiasts are silver-haired ranchers. Entomologist Joel Price is only 37 years old. And he said there are a number of new ideas coming in with younger employees. For example, the program collected beetles from the wild so they could be transferred to areas where a weed was flowering.

Now they find it more efficient to just collect a few bugs in the wild, around 70, and then put them in a growth chamber. A grow chamber looks like a refrigerator, but inside it simulates long hours of daylight, warm temperatures, and plenty of food. After a few weeks, 70 bugs in a breeding chamber can grow to 7,000 bugs, which can then be easily distributed.

“It’s quite difficult to predict where and when bugs will be collected across the state with these wild, climatic events and things,” Price said. “So rearing in a lab is much more controlled and predictable.”

Entomologist Joel Price of the Oregon Agriculture Department checks the growth of beetles in a laboratory growth chamber.  November 2022

Entomologist Joel Price of the Oregon Agriculture Department checks the growth of beetles in a laboratory growth chamber. November 2022

Kristian Foden-Vencil / OPB

Price said the program is also pushing the boundaries of weed control bugs to include weed control pathogens. Such pathogens include fungi and nematode worms.

There are some people who don’t like the introduction of alien species or herbicides used on weeds, but many environmental groups support Oregon’s weed program.

Mark Salvo of the Oregon Natural Desert Association said herbicides may not be the association’s first choice, but the harmful weed problem is so bad that they are willing to consider all means. “And sometimes that can involve the use of herbicides,” Salvo said.

When Lane County announced a plan to spray roads, the local chapter of the Native Plant Society of Oregon released a statement acknowledging that herbicides may play a role in vegetation management.

Don Farrar, Gilliam County Poisonous Weed Chief, with his pickup truck and equipment.  “The toadflax had been here for years.  It just gradually took over and got worse and worse and worse.  And farmers used harsher chemicals to try to control it.  And they didn't really keep up, and neither did we.

Don Farrar, Gilliam County Poisonous Weed Chief, with his pickup truck and equipment. “The toadflax had been here for years. It just gradually took over and got worse and worse and worse. And farmers used harsher chemicals to try to control it. And they didn’t really keep up, and neither did we.” September 2022

Kristian Foden-Vencil / OPB

Back in Gilliam County, Don Farrar explains that weeds are just a plant that we’ve decided is out of place. And one of the main ways weeds travel is through road traffic. Branches can ride in a vehicle’s undercarriage, or seeds can fall into a comfortable bumper curve.

“Cars carry weeds,” Farrar said. “All it takes is picking up a mustard and taking it to the next county to get it there.”

Spraying along Gilliam County roads will now begin in late fall, before it snows, to allow moisture to carry the herbicide into the soil. In spring, when weeds try to grow, germination is blocked.

Entomologist Joel Price examines some weeds he's using to feed a growing beetle population.  November 2022

Entomologist Joel Price examines some weeds he’s using to feed a growing beetle population. November 2022

Kristian Foden-Vencil / OPB

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