As Oregonians begin to get rid of their Christmas trees, state officials are warning some could house an unwelcome present.
On Friday, the Oregon Department of Forestry sent out a release asking Oregonians who bought Fraser firs from big-box stores to be careful when disposing of them, as they may be carrying a non-native insect species known as the elongate hemlock scale.
The tiny insects are new to the Western United States but have lived on the East Coast for more than a century. Forestry officials are concerned that the bugs could spread quickly in Oregon’s forests and damage fir and western hemlock trees.
“Nobody would want to be the source of an outbreak that could kill trees,” said Jim Gersbach, spokesman for ODF.
Wyatt Williams, invasive species specialist for the state agency, said the elongate hemlock scale, which typically grows to about 2 millimeters, was discovered in America in 1908 and has been spotted on the Eastern Seaboard from Massachusetts to North Carolina.
The insects make their home on the undersides of needles from evergreen trees, particularly hemlocks, and use their strawlike mouths to suck fluid out of the leaves, causing them to drop prematurely.
“They essentially glue themselves to the needles,” he said.
About 8,000 Fraser fir trees were transported to the West Coast from North Carolina to be sold as Christmas trees at large chain stores. After discovering elongate hemlock scale on some of the trees, California agriculture officials notified Oregon and other states about the insects Dec. 13, Williams said.
Williams declined to speculate about which stores had carried the trees or how many of the trees many be home to bugs. He said, however, that trees where shipped to stores from Alaska to Utah. In Oregon, state officials contacted the company that brought the trees from North Carolina, and the company opted to destroy the trees.
Williams said the insects mate and lay eggs on a tree’s needles. Once the eggs hatch, immature insects can be carried by wind currents to other trees, where they can begin feeding on a new host.
“It’s very hard to kill once it gets going,” Williams said.
Gersbach said the insects prefer fir and hemlock trees, and thus pose more of a threat to forests located west of the Cascades, where those trees are more common. However, he said, ODF is still concerned about residents of Central and Eastern Oregon putting trees in yards where they might be close enough to ornamental fir trees to allow the bugs to spread.
What you should do
Anyone who bought a Fraser fir from a chain supplier should check the tree’s needles to make sure the small, waxy-coated insects aren’t present, Gersbach said. To dispose of the trees safely and effectively, Gersbach recommended cutting them up, putting the pieces in garbage bags and taking them to the landfill.
“We’re trying to be extra-vigilant, and we’re asking the public to bear with us,” Gersbach said.
Williams said the elongate hemlock scale, like other invasive pests, poses a particular threat to Oregon’s native plants because they haven’t had a chance to evolve alongside the bugs the way they would with native foes.
“They’re kind of like sitting ducks; they have no way to defend themselves,” Williams said.
‘Big threat’ to forests
Williams estimated that between five and 20 invasive species are discovered in Oregon each year, typically after being inadvertently transported across oceans on plants or inside wood packaging.
“Right up with climate change, they’re a big threat to our forests,” he said.
The Oregon Invasive Species Council, an interagency group established by the Legislature in 2001, maintains a website where Oregonians can learn about and report possible invasive species they encounter, at www.oregon invasiveshotline.org.
In addition to inspecting and disposing of infested trees, Williams encouraged Oregonians to buy locally grown Christmas trees in the future.
“We have plenty of very good native Christmas tree producers in the state,” he said.