I dislodged one of the "shells" to show the base attached to the leaf. The attachment was strong and it was not easy to avoid damaging the wax. The base of the shell had a black structure (I believe it is a pupa or fourth instar whitefly) and a brownish membrane that remained on the leaf surface.
See a nicer series of the same specimens by Mr. Harald Grieb at:
The base of these critters looks almost identical to this photo posted as whitefly pupa
on oak leaves.
A journal article on Aleuroplatus gelatinosus
and Redescription of two live oak-infesting whiteflies in California
On the underside of Southern live oak (Quercus virginiana) leaves. These critters remind me of whitefly pupae.
Update: I went to collect samples two days later (1/5/16) and viewed them under a microscope. All the specimens checked look like empty shells, but upon closer inspection the black structure at the base of the "shells" is probably the fourth instar or “pupa” of a whitefly in the genus Aleuroplatus. The structure at the base was not produced by the leaves, but by the insect and "glued" to the leaves. I doubt that all the holes are exit holes from a parasitoid because that would imply 100% parasitism; which I think is unlikely. These photos do not show the holes (except for the last one) because inadvertently were shot from the side opposite to the hole. I plan to check these trees in the spring and summer hoping to collect live bugs and photograph other developmental stages.
Also, I mailed samples to a whitefly expert and will provide updates here as soon as he determines this bug's identity.