Oak gall - Andricus chrysolepidicola

Moved

… Joyce Gross, 18 January, 2012 - 11:07am

Moved

Moved from ID Request.
Joyce Gross will see your photo here sooner or later and will probably be able to confirm the ID.

… Charley Eiseman, 30 December, 2011 - 3:55pm

Andricus chrysolepidicola?

Could it be that? It is reported on blue oak, the images I am finding with google appear far more disformed, but I initially discovered the name in "A Field Guide to Insects and Diseases of California Oaks" by Tedmund J. Swiecki & Elizabeth A. Bernhardt with a picture that much more so resembles what I found, but doesn't elaborate much on it outside of host.

… Byrain, 30 December, 2011 - 3:46pm

Swiecki & Bernhardt reference added

BugGuide bibliographic entry here (the photo you referred to is on pg. 30).

… Aaron Schusteff, 15 July, 2020 - 8:56pm

yes, Andricus chrysolepidicola

As long as it came from Quercus douglasii then it is an Andricus chrysolepidicola gall. Have seen galls just like this (with less deformity than pictured in Russo's book) on Q. douglasii.

However if the gall came off Q. agrifolia or Q. wislizeni, then the gall would have been created by a different species, Callirhytis quercussuttoni. Were there any Q. agrifolia/wislizeni right where you found the gall?

… Joyce Gross, 18 January, 2012 - 11:14am

Oak species

Yes, both Q. agrifolia and Q. wislizeni are both present at this location and I would imagine neither were all that far from the spot I found the gall, but I am quite sure this gall did not come from a live oak as the leaves attached to the twig were lobed. You can find a list of plants (And oaks) at Stebbins here - http://nrs.ucdavis.edu/stebbins/species/popweb1.htm .
Apparently the only other oak with lobed leafs present is Q. lobata, but this species I am rather familiar with since it is everywhere near my house and I really don't remember seeing much if any specimens at Stebbins in the past. I will keep my eyes open for it in the future.

Also, thanks a lot for taking a look at my recent gall pics, they're lots of fun to find. :)

Edit: As I still have the gall I noticed just now that either it shrunk as it dried (I thought it was already mostly dry) or my previous measurements of "4 cm tall, 2 cm wide" were off (I'm not sure how as I used a ruler)...
Either way I changed the measurements to their current size.

… Byrain, 18 January, 2012 - 3:31pm

Another gall image presumably of this species

...is here, reminscent of a peanut!

Also...there's lots of interesting & detailed life history info on A. chrysolepidicola in Burdick(1967). The stem galls are formed by the longer-lived parthenogenetic (all female) generation.

It would be wonderful to get images of the much smaller leaf & flower bud galls of the alternate (shorter-lived bisexual) generation too. (There's a line drawing of it in Russo(1), his "Fig. 39").

And it would be fantastic to get photos of adults of either or both generations! ;-)

… Aaron Schusteff, 15 July, 2020 - 8:59pm