Invasive Emerald Ash Borers On The Loose, Prompts Washington County Quarantine

To stop the emerald ash borer from spreading, the Oregon Department of Agriculture imposed a temporary quarantine in Washington County in December.

The short-term quarantine started on December 20 and will last until May 16. The quarantine prevents the transport of any ash, olive, or white fringe tree materials outside of Washington County.

This includes firewood made from hardwood species as well as logs, green lumber, scion wood, bud wood, nursery stock, chips, mulch and stumps, roots, and branches.

Emerald Ash Borer in Washington County

State officials are attempting to stop the emerald ash borer from continuing to spread to other Oregon counties even though it has only been found in Washington County thus far.

The Oregon Department of Agriculture (ODA) has implemented a temporary EAB quarantine in response to the discovery of the emerald ash borer (EAB) in accordance with Oregon Administrative Rule (OAR 603-052-0135).

In June 2022, several ash trees in Forest Grove were found to have the invasive pest, which was then the first time it was seen in Oregon. This was also the emerald ash borer's first confirmed sighting along the West Coast.

Outside of Forest Grove, the insect has not been found anywhere else in Washington County.

A Decade of Killing Ash Trees

In some parts of North America, these invasive and destructive beetles have decimated up to 99% of the ash trees. As the invasive emerald ash borer continues to spread across the nation, at least five Central American native ash species have become critically endangered.

Ash trees in Europe and other regions of North America have also been severely damaged by the emerald ash borer. Ash tree bark is penetrated by its larvae, which results in the death of the canopy and the eventual death of the affected trees.

According to the Oregon Department of Forestry, most ash trees would be dead or dying within ten years of the emerald ash borer's arrival in a region, endangering the native Oregon ash tree.

Also Read: 1.4 Million Urban Trees Will Be Dead By 2050 Due to Infestation of Invasive Species

Invasive Emerald Ash Borer

The emerald ash borer is about half an inch long and an eighth of an inch wide. It is renowned for its shiny, metallic green hue.

Trees with thinning and yellowing leaves, split bark, D-shaped holes in the bark, and basal shoots may be infested.

The general public can take action to slow the emerald ash borer's spread.

The first step is to report any and all beetle sightings. The Oregon Invasive Species Council Hotline encourages people to report emerald ash borer sightings online.

Ash trees should be taken off the list of permitted street trees, according to the Oregon Department of Forestry.

Officials advise replacing the ash trees with resistant species like Chinese pistache, Oregon white oak, and incense cedar.

To prevent the spread of ash, olive, and white fringe tree materials, the Oregon Department of Agriculture is developing several processing and disposal facilities in the quarantine zone surrounding Washington County. A list of locations to dispose of tree debris is available online.

The department stated that it will assess upcoming quarantine criteria as more information becomes available, KOIN6 reports.