I missed the pupal stage once again. Some of them were dead or dying inside the partially open galls; others emerged rather groggy after being rudely awakened by my knife. It seems that I accidentally broke the antennae or wings of some of them.
The date is April 19, 2010 but I don't include it in the data field because I have kept them indoors and they may have emerged later if left outdoors.
The larger ones with a big belly are about 3.5 mm and I suspect that they are females; The leaner, smaller ones are about 2.5 mm and probably males.