PORTLAND, Ore. (KOIN) – Portland is bracing for yet another threat to the city’s greenery. The emerald ash borer, a half-inch-long metallic-green beetle, is expected to arrive in Portland soon. More than 95,000 trees are at risk.

Portland Parks and Recreation‘s Urban Forestry division recently released a plan to manage the insects, which have already been found in Washington, Yamhill, Marion and Clackamas counties.

“Emerald ash borer’s arrival in Portland is imminent if it is not here already,” according to the report.

“Losing our ash canopy will have a detrimental effect on shade equity, habitat, and Portland’s efforts to manage urban heat and extreme weather events which are likely to become more frequent because of the changing climate,” the report said.

The city’s strategy includes working with state and regional partners, as well as the public, to monitor the emerald ash borer spread. It also encourages the use of insecticides to preserve ash trees on public as well as private property, and calls for the removal of trees that are in developed parks and are not able to be treated with insecticide or other methods.

“This is why we actively push for diverse species when we plant and promote tree planting,” said City Forester Jenn Cairo. “So that when a disease or pest attacks one species, it causes less harm to the canopy as a whole.”

Portland has about 95,000 ash trees, according to the report, with 10% planted in developed areas. An estimated 72% are in natural areas, including Oaks Bottom Wildlife Refuge and the Columbia Slough. Citywide, they represent 1% of the entire urban forest.

The little green bug has killed more than 100 million trees in the United States since it was first discovered in Michigan in 2002. It was first detected on the West Coast in June 2022 in Forest Grove, Ore.

The emerald ash borer is native to Asia and has few predators, making it difficult to eradicate. Woodpeckers and a few species of wasps will eat them. Infested trees usually don’t live longer than 3 or 4 years before they turn brittle and die.

“By diversifying tree species, using data-driven tools, and planning ahead, we’re better prepared to face threats like EAB and build a resilient, healthy canopy,” said Deputy City Administrator Priya Dhanapal.

In 2019, the ash tree species was removed from the city’s approved street tree planting list. Recently, new rules were also put into place that allow residents to treat or replace small ash trees with free permits.

The public can help identify signs and symptoms of the emerald ash borer by reporting possible sightings to the Oregon Invasive Species Council’s reporting hotline, at oregoninvasiveshotline.org.