Unknown egg - Atrusca quercuscentricola

Moved

Moved from ID Request. A new genus for the guide. You can click the gray "info" tab above the image to see the description I found. If the gall wasn't parasitized, there is probably already an adult wasp inside--but she may not chew her way out until the spring, or maybe even several springs from now.

… Charley Eiseman, 19 December, 2009 - 9:35am

Leaf photo?

Can you provide a photo of the whole leaf? That would be very helpful.

… John Pearson, 17 December, 2009 - 6:36pm

Post oak?

I have a gall in mind, if you think it's possible this was post oak.

… Charley Eiseman, 19 December, 2009 - 12:22am

In the white oak group...

...with rounded lobes and no bristle tips. Post Oak (Quercus stellata) is in that group and is a tempting choice because the photo shows only a single pair of lobes (forming a cross along the right edge of the tape) and the base of the blade appears to be rounded (judging from the projected outline of the leaf margin at the right edge of the photo). The one intact lobe on the bottom of the photo appears a bit narrow for Post Oak (and more like White Oak (Q. alba)), but the leaf could have been young and small when deformed by the gall. A wider photo would remove much guesswork, but Post Oak is a very good tentative ID.

… John Pearson, 19 December, 2009 - 8:51am

Thanks

With that in mind, I'll go ahead and make a species page for this. Most of the "oak apples" are found on leaves of the red oak group, so I was happy to find a photo of a gall just like this that is found on post oak. Even if this isn't post oak, this cynipid species would be most likely, since it seems to be the only option for the white oak group.

… Charley Eiseman, 19 December, 2009 - 9:19am

Post oak

Thanks for posting those whole-leaf photos! Yes, this is indeed post oak, albeit a highly tattered and deformed specimen. The rounded base, the crossing lobes, and the very glossy upper surface are key indicators. Nice find!

… John Pearson, 19 December, 2009 - 11:12pm

It's actually...

called a gall which is a growth on the leaf. There are larva growing inside, probably Family Cynipidae (Gall Wasps).

… Scott Justis, 17 December, 2009 - 1:59pm

Learn something every day....

Thank you for Identifying this for us...
I've never heard of a gall before... Lots of strange insects within the United states
I/We would of lost sleep thinking about it... wonder no more now

… curiousity, 17 December, 2009 - 2:12pm

Definitely a cynipid wasp gall

There are hundreds of North American species, each making a particular type of gall on a particular part of a particular type of oak (and a few other plants). Would need to know what kind of oak this was to figure out what wasp species (although I could come up with a few suspects without that information). You can see many examples if you browse through the images here.

… Charley Eiseman, 17 December, 2009 - 2:27pm

Maybe Someone...

with more expertise than I can narrow the ID down better.

… Scott Justis, 17 December, 2009 - 2:25pm