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Exudate from pin oak trunk #802517

Asked July 22, 2022, 4:08 PM EDT

Hi. I recently inspected a pin oak in Takoma Park that is in decline and found a strange pattern of oozing on its trunk. Some sort of exudate and possibly frass from a boring insect. The oozing masses were larger than the frass tubes of ambrosia beetle, and were perhaps 3/8 inch wide. See attached photos. Any idea what this is?

Montgomery County Maryland

Expert Response

We don't see Ambrosia Beetle frass tubes, but this looks like slime flux or wetwood, a relatively common and often non-serious condition in older trees. If the tree is in decline, other factors are responsible and likely began many years ago, even if symptoms weren't obvious at the time. We'll share a few page links discussing tree decline if you're curious (particularly among oaks in suburbia), though a tree can be assessed by a certified arborist to better narrow-down possible causes. Arborists can't always intervene, though, and treatments won't resolve existing damage. They might be able to identify sources of ongoing tree stress, though, in case they can be alleviated.

Miri
Thanks!  Slime flux makes sense.  What appeared to be frass in the flux threw me off, but my eyes may have been playing tricks.
On Fri, Jul 22, 2022 at 5:05 PM Ask Extension <<personal data hidden>> wrote:
The Question Asker Replied July 25, 2022, 3:24 PM EDT

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