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Photo#357585
Family Cynipidae - Gall Wasps on oak twigs - Disholcaspis quercusglobulus

Family Cynipidae - Gall Wasps on oak twigs - Disholcaspis quercusglobulus
Raleigh, near Rts 50 and US 70, Wake County, North Carolina, USA
November 16, 2009
Size: Gall 13mm
Nov 16: My driveway, under 2 Quercus alba (White oak), 3 Q. coccinea (scarlet oak), and a Carya alba (mockernut hickory) is littered with scores of 3-4 inch abscised twig ends with one (or occasionally two, opposite) galls like this. The galls are hard and of uniform size and have no holes in them.

Dec 09, 23 days later: I used a kitchen knife to cut open one of the above 13mm galls. It contained a 3.2mm white legless larva in a smooth sphere, a ball of tan granular excrement that held into a ball, and silk.

Images of this individual: tag all
Family Cynipidae - Gall Wasps on oak twigs - Disholcaspis quercusglobulus Family Cynipidae - Gall Wasps on oak twigs - Disholcaspis quercusglobulus Family Cynipidae - Gall Wasps on oak twigs - Disholcaspis quercusglobulus

Moved
Moved from ID Request.

Disholcaspis
These would seem to be round bullet galls, but according to Weld the adults should have emerged by now. This must be a parasite or "guest" wasp larva. The excrement and silk suggest that some kind of moth larva has been in there too... puzzling, since you say there were no holes. It would definitely be worth hanging onto these (in some unheated place) to see what comes out.

 
More round bullet galls.
Today I searched the ground under my white oaks and came up with about 20 twig ends with these galls. Four of them had exit holes. One had a tiny hole. I put non-moldy examples of these 3 categories in 3 containers to see what happens.

Many thanks for your research, Charley!