Acorn Weevil Grubs
Rosie likes to collect acorns, and had brought a bucket of them in the house on October 7, 2012. And while Sam was looking them over, she somehow broke one of them (I think she dropped it on the floor). And inside, there were several of these fat little white grubs.
They had completely hollowed out the nut, which would have been a bit of a surprise to any squirrel that might have collected it. These are about as featureless as grubs get, just a brown head and a bag-like white body.
They didn’t have any legs as far as I could see, and they moved by a combination of dragging themselves forwards with their jaws, and pushing themselves with the tips of their tails. It wasn’t fast, but they could at least progress that way.
These are clearly some sort of Acorn Weevil, in the genus Curculio. And if acorns were edible to humans, they’d be quite a pest. But, since acorns taste nasty because of all the tannins in them, these particular beetles are only pests as far as squirrels are concerned. Actually, maybe not even then. The squirrels are probably perfectly happy to eat the grubs, too.
I tried to raise them up to see exactly which kind of acorn weevil they were, but failed miserably because I didn’t understand the conditions they needed. It seems that they bore out of the nut and burrow into moist leaf litter to pupate, and I didn’t provide them with the moist leaf litter. This suggest that the standard conditions for raising insects that emerge from nuts, fruits, or galls should probably be a tallish jar with a layer of moist soil covered by appropriate leaf litter.
 There is a similar grub that infests hickory nuts, which are edible. Sandy’s parents have some hickory trees, and the last time we helped them shelling the nuts, we found about one nut in 20 that had a grub similar to this in it.
 Actually, if these grubs don’t concentrate the tannins from the acorns, they might actually be pretty tasty if stir-fried with rice. In which case, they could be useful for making acorns edible.