The Oregon Department of Forestry is assessing the threat of a beetle that’s killed hundreds of Oak trees in California and has been found in our state.
The first report of an Oregon White Oak tree infested with the Mediterranean oak borer came last May at the Sandy River Delta in Troutdale. It’s been found in a couple of insect traps as well.
Wyatt Williams is the invasive species specialist with ODF.
“We don’t know if this will be a major pest or a nuisance pest or no pest at all,” said Williams. “It could be that this beetle goes after weak, stressed trees, or as in the case of California, it is attacking and killing both weak and vigorous.”
Oregon officials are trying to find out more about the beetle. Meanwhile, they’re asking Oregonians not to move firewood from oak trees beyond the local area where it’s cut, to avoid spreading the pest.
Williams said you can look for signs to determine if your oak tree might be infested with the Mediterranean oak borer.
“A, is part of the canopy declining and brown while the other part is healthy and green?” Williams said. “B, if you walk up to the tree, is there sawdust around the base and crevices in the bark? And C, if you can get into the wood, does it have those characteristic black tunnels that appear as tiny shot-holes throughout the wood?”
If you suspect you’ve found an oak tree affected by Mediterranean oak borers, you can report it to https://oregoninvasiveshotline.org/.
Signs and symptoms of Mediterranean oak borer infestation
1) MOB is a tiny, reddish-brown beetle that can be confused with many other beetles that reside in oak.
2) Pale boring dust is kicked out by the beetle and found on the exterior trunk of the tree.
3) MOB galleries look like tiny black holes from the exterior of the wood and,
4) black, branched trellises on the cut face of wood.
5) MOB create tiny, perfectly round entrance holes.
Symptoms not from MOB: holes larger than the diameter of a pencil lead, brown boring dust, discolored leaves but absence of dieback, wood staining without associated galleries. For info on other oak pests go to: https://www.oregon.gov/odf/Documents/forestbenefits/Oak_galls_2017.pdf
Copyright 2023 KLCC.
