Bee or wasp hive in Arborvitae
We've discovered that there is a bee or wasp hive in one of our large arborvitae trees, and it's starting to affect the health of the tree.
Any suggestions on how to tackle this or referrals to experts?
Multnomah County Oregon horticulture
A wasp nest discovered this late in the year is unlikely to cause much more damage to the tree. If it is a type of paper nest, the insects do not winter-over inside it, so removal once it is abandoned is easy.
What does the nest or insect look like? Don't get too close: sometimes enlarging a phone photo gives a clearer view. Large football-shaped paper nests are bald-faced hornets, Dolichovespula maculata. The bald-faced hornet is a type of yellowjacket wasp that builds nests above the ground. It gets its common name from the largely black color and mostly white face. They can be aggressive if you get close to the nest. If it needs to be removed for safety, consider the aerosol products because they can spray a long distance. Follow the label instruction carefully: additional information on page 5 or this publication from Washington State University Extension Service, EB0643: https://ehs.wsu.edu/PH/pdfs/Yellowjackets%20and%20Paper%20Wasps.pdf
If it appears to be a honeybee nest, we can provide referrals to services to remove the bees.