California black oak

Moved

Moved from Section IV (oak and birch family leafminers).

Although the leaf mine is visible in this photo, the dominant feeding sign is not caused by Bucculatrix larvae. I'm pretty sure now it's the work of some kind of weevil (see this post). The third photo likewise is unrelated to the Bucculatrix.

… Charley Eiseman, 28 January, 2016 - 2:02pm

Moved

Moved from Unidentified Signs on Algae, Fungi, and Plants.

… R. Berg, 28 January, 2016 - 1:57pm

Moved

Moved from Unidentified Leaf Mines.
Somebody will have to go to Yosemite in the spring and catch the culprit in the act!

… Charley Eiseman, 13 October, 2012 - 11:05am

I went there . . . no luck!

I visited the Valley this April 14–18. The black oaks haven't leafed out yet or even budded. This skeletonizer must have a short eating season.

… R. Berg, 20 April, 2013 - 3:32pm

At least we're narrowing it down...

I bet it shows up soon after the leaves expand.

… Charley Eiseman, 20 April, 2013 - 7:53pm

More about seasonality

Other trees there are ahead of schedule this year, compared with last year, so black oaks must typically get their spring growth quite late. That would make this unknown creature's larval season very short. In 2012 I posted photos taken in the Valley on April 18 and 19. That year, manzanita and redbud were blooming at elevations 1,000 feet lower but not in the Valley. This year, I went a few days earlier. Many redbuds were budding and a few specimens were in full bloom. Some manzanitas were also blooming. (This was a warm, dry winter.) All the black oaks I saw looked wintry. They had shed most of their leaves. The leaves remaining on the trees were dead.

… R. Berg, 20 April, 2013 - 10:29pm

Probably me

Oh, what sacrifices we make for the advancement of knowledge!

… R. Berg, 13 October, 2012 - 11:44am

I would love to know...

I took photos of this exact thing while waiting in line at the Yosemite entrance in July 2008. I have no idea what insect is responsible, other than that it must be something with chewing mouthparts -- caterpillar, sawfly larva, beetle...

… Charley Eiseman, 12 October, 2012 - 3:58pm

You don't know?

But-- but--

You're the Tracks and Signs guy!

As long as I've got you here, ever seen one of these?

… R. Berg, 12 October, 2012 - 4:33pm