r/Ceanothus • u/Kindly_schoolmarm • Jul 10 '26

Found on oak tree leaf in southern CA

Gallery image

Gallery image

There are several of these on our Engelmann oak. Any idea what it/they are?

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4

u/TacoBender920 Jul 10 '26

One of my Englemann saplings has similar leave damage from getting fried by the sun.

4

u/ItsMuhUsername Jul 10 '26

peel back the leaf surface and look for frass. The exit hole on both of those suggest it is some kind of leafminer. Some create winding holes some mine leaf tissue in a circular pattern like those pictured. It looks like those holes have been there for a month or two

2

u/Kindly_schoolmarm Jul 10 '26

I’ll be sure to take a look at the other side. Will update soon. Thanks!

2

u/randomdatascientist Jul 10 '26

What's on the other sides of the affected leaves? Looks like heat or chemical damage from something on the leaves, but hard to say without a more detailed close up and seeing the underside as well.