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Boxelder bugs #928560

Asked April 16, 2026, 9:32 AM EDT

Hello. I have a giant sequoia that is invaded with boxelder bugs. In the spring and fall I have been spraying it with malathione. It seems to be working but I'm concerned that they have invaded the tree because of disease. The tree looks good. Opinions??

Douglas County Oregon

Expert Response

Boxelder bugs in invade trees, to feed on seeds, leaves, and sap, using them as a primary food source and breeding ground during spring and summer. In fall, they congregate on these trees seeking warmth before seeking overwintering spots in nearby sunny building walls or debris.
To help with control: Remove litter, wood piles, and debris around the base of trees to reduce overwintering habitats. Spray congregations on trees with a strong stream of water to dislodge them.
While they are a nuisance, they do not cause significant structural damage to the trees.
Here is a publication for more information:

https://extension.oregonstate.edu/ask-extension/featured/stink-bugs-boxelder-bugs-everywhere


Chris Rusch Replied April 17, 2026, 10:42 PM EDT

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