I have created this page to keep track of the various wasps that have emerged from little round galls I've found attached to the veins of Quercus alba leaves, which don't match any described galls to my satisfaction. I've sent the cynipids to the USDA Systematic Entomology Lab for identification, so eventually I should have a name for them and the information collected here can be transferred to a species page.
In March 2010 I collected a white oak leaf with these two spherical, 4 mm galls, plus several tiny galls that I believe are caused by Neuroterus tantulus. On 4/28/2010, a 2 mm cynipid had emerged from one of the spherical galls:
This ~1 mm eulophid had also emerged, and I couldn't find any exit holes in the tiny galls (which were themselves 1 mm across), so I believe it also emerged from the same gall:
On 12/20/2010, I was doing a little housecleaning and found that this 2 mm cynipid had emerged from the other spherical gall and died, presumably months earlier:
On 4/18/2011, I collected a bunch of leaves with what I believe to be the same type of galls. On 5/4/2011, a pteromalid parasitoid emerged from one of them:
In the same bag (which contained just one leaf), I also discovered a dead 0.8 mm cynipid, which could have come from the same gall, but I noticed some inconspicuous blisters along the leaf midrib which had a few exit holes that matched the size of this wasp.
There were two other 3-4 mm galls on the same leaf, and on 11/27/2011 I discovered that two wasps like this one had emerged from them:
The rest of the leaves with the little spherical galls were all stuffed into a single bag together. On 5/5/2011 I noticed a couple of little green wasps in this bag. I put the bag in the fridge and didn't get to dealing with the wasps until 5/7. On that day I found and photographed one dead pteromalid and one live eurytomid. The other green wasp, presumably another pteromalid, got loose in my house and I never got a photo of it.
I searched carefully and was only able to find two galls with exit holes. One gall was 4 mm across; the other was 2.5 mm and had a correspondingly smaller exit hole. If a cynipid and a eulophid could emerge from one of these galls, I suppose it's reasonable that a single gall could also produce two parasitoids.
Back on 4/18/2011, under the same tree that produced the galls and wasps shown above, I had filled another bag with leaves bearing much larger, fuzzier galls, which I believe to be the work of Philonix nigra. On 5/7/2011, I found this pteromalid in that bag:
It appears to me to be the same species as the dead one above. I searched all the galls for exit holes, and the only one I found was in the small (3 mm) gall in the cluster shown below.
Whether this is a runty Philonix nigra gall or one of the other kind that happened to be produced next to some Philonix nigra--or maybe they're all Philonix nigra--I don't know yet.
On 5/22/2011, I found an adult female cynipid that had emerged from one of the galls collected on 4/18. I'm not sure if it's the same species as the dead female from 2010, but it looks like the same species as the male.
On 6/3/2011, I returned from a 10-day road trip to find a dead female cynipid had emerged from a gall I collected on 4/23/2011. It looks like the one from 12/20/2010.
On 6/6/2011, I found a dead pteromalid that had emerged from a gall collected on 3/10/2011:
On 7/8/2011, I found a dead cynipid that had emerged from a gall collected on 4/18/2011: