Ambrosia Beetles

What it looks like

The telltale sign is thin, toothpick-like tubes of sawdust (frass) sticking straight out of small holes in the trunk. These beetles go after trees that are already stressed, weak, or freshly transplanted, and can kill a struggling tree quickly.

Often mistaken for: Other trunk-boring insects, but the toothpick-like frass tubes are a distinctive giveaway.

When it shows up in the Triangle

They're most active and damaging in early spring, roughly March through April in our area, once temperatures first warm into the 60s.

Where you’ll see it

Recently transplanted or stressed trees and shrubs, including maple, dogwood, crape myrtle, and cherry-family ornamentals.

What you can do

• Give new trees the best possible start — plant at the correct depth, not too deep
• Water new transplants consistently through their first two growing seasons to reduce stress
• Check trunks in early spring for the telltale frass tubes
• If you see frass tubes, remove and destroy the affected tree or branch promptly — it's usually too late to save it and it can spread beetles to nearby trees
• Avoid planting stressed or marginal trees in problem spots to begin with