This is western cedar borer. It is not of concern as it's native and attacks dead and dying trees - often drought-stressed arborvitae in sun-exposed lots. Emerald ash borer is smaller and thinner than this beetle. There are a number of iridescent green look-alike beetles in Oregon that are not pests. I am attaching a link to the ODA EAB webpage with some photos of other Oregon insects that could be mistaken for EAB

https://www.oregon.gov/oda/programs/IPPM/SurveyTreatment/Documents/EABLookAlikes.pdf

Thanks for being on the lookout!

Josh Vlach
Aug. 22, 2022, 1:42 a.m.