If you've ever wondered how invasive species can cost the United States $20 billion every year, the emerald ash borer is here to show you.

What's happening?

Since arriving in the United States from Asia, the beetle has killed an astounding 100 million trees. It wasn't detected in Oregon until 2022, but conservationists there say its newly discovered presence in three counties shows that it could have evaded notice for over five years, as Oregon Public Broadcasting reported.

Marion, Yamhill, and Clackamas Counties are the latest areas to suffer the effects of the insect, whose larvae eat the inner bark of ash trees, including the Oregon ash, which prevents them from absorbing nutrients such as food and water.

A couple of things tipped off officials about a potentially devastating proliferation of the beetle in Oregon. It had not been seen outside Washington County, but traps that caught multiple beetles in Marion County and a possible infestation there near the Clackamas border sounded the alarm.

"I was shocked," Oregon Department of Forestry invasive species specialist Wyatt Williams said of the latter situation. "I immediately saw dead trees up and down this drainage. … My heart kind of sank. I did find an infested tree right away."

Why is this important?

Part of the reason the beetles can go undetected is that the trees they infest can take up to five years to die. Washington County has been quarantined, but that has not stopped the emerald ash borer from wrecking shop miles away.

The aforementioned traps — large purple sticky sheets — only serve to alert to potential problems. If there are "that many [five] beetles on a single trap," that means "there is a significant population in that area," Williams told OPB. But local ash trees can still appear healthy, as was the case in Marion County.

Trees that show signs of the beetle can have tears in the bark, dead branches, and D-shape exit holes. But that likely means it's too late.

And that could be devastating for the state, which is not the only one under attack from the ash borer. One ash tree can pull 48 pounds of carbon dioxide out of the air and generate the oxygen needed for two people.

What's being done about the emerald ash borer?

OPB reported that land managers are cutting down infested trees, treating healthy ones, and monitoring for the borer to help protect property and landowners, who can plant other species and treat their ash trees with pesticides before they're infected. 

The quarantine bans the transport of firewood, where the beetle can hide out. People are also not allowed to move logs, lumber, nursery stock, wood, or mulch, according to OPB.

Even those in other areas should avoid moving any of those items.

"We want to protect the rest of Oregon for as long as possible to give communities more time to prepare," Cody Holthouse, the state Department of Agriculture insect pest prevention and management program manager, told OPB.

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