There are a lot of things "a little white worm" could be. It's easier to identify the possibilities by the damage they did rather than the worm they are.
If they're curculio I wouldn't hold your breath hoping for an organic solution. They leave a small crescent on the fruit when laying eggs.
I think cherry maggot fly leaves a small dot. I imagine there's an organic solution for them. If not there are minor chemical solutions that would take care of them. I use Malathion for their cousins the Apple Maggot.

Worms in cherries are easy to miss. The easiest and most assured way of not getting them is to avoid damaged cherries. Then when you're pitting them if one puts out brown frass pitch it, there's a worm or was a worm.

Sheila:

You are probably the victim of the cherry fruit fly. Google this term and read all about it. This nasty insect has no respect for modern maturity, attacking older as well as young fruit growers.

Spraying tart cherry trees for this insect is problematic, since tart cherries mature so early that chemical sprays have little time to break down before picking. And you can't scrub a cherry before pitting; about all you can do is a cold-water rinse.

I am not a organic person by nature, but have found what I believe to be a successful cultural procedure to practically eliminate this insect. First, make sure you take all the cherries down from the tree and pick up those you can find on the ground, then discard them in the trash. If any of those fallen or falling cherries contain fruit fly larvae, they will burrow into the soil and pupate, ready to emerge for next season. You need to break this reproductive cycle.

Second, and perhaps more important, hoe or otherwise cultivate beneath the tree to a depth of 3-4 inches at least out to the dripline several times during the winter. This will expose the pupae in the soil to cold, drying Nebraska winds, which will kill them. Cherry fruit flies usually hatch out right beneath the trees that they prey upon, and unless interrupted their numbers can build.

The entry wound of the cherry fruit fly is very small, almost pinhead size. The larvae show up in the fruit without much warning, requiring close attention from the operator of the pitter. A little black frass around a pitted cherry is the signal to stop the pitting line and rinse the pitter. These larvae do not develop overnight; they were probably present in the first batch of cherries you pitted, but were too small for you to see. They are not toxic, of course, but it is better to be rid of them.

I have been growing tart cherries for over 30 years in a climate that is heaven for this insect, but have pretty much eliminated them by the pickup/hoeing procedure.

Don Yellman, Great Falls, VA

-----These larvae do not develop overnight; they were probably present in the first batch of cherries you pitted, but were too small for you to see. ----

EEEEeeeeeeeeewww. How do I get THAT picture out of my head?

Carla in Sac

If you didn't even notice them while you were eating the cherries... where's the harm? Heck, I would have made a pie out of those cherries even if I *knew* the little maggots were in there.

I have not had a problem with these yet but continue to grow more and more cherries. I believe the problem begins to happen when not all of the cherries are harvested and some are let go. I've read on this forum and in many other locations that the fruit flies primarily come from the ground directly beneath the tree typically. If all the fruit are picked I don't see how they would be able to over winter in the ground. I don't like the idea of spraying every 7 days up until harvest. At this time I spray fungicides several times throughout the year to prevent leaf spot. Can these be primarily controlled through cultural management? My second choice of control would be carbaryl because I feel it's relatively safe.

Here is a link that might be useful: WESTERN CHERRY FRUIT FLY (Rhagoletis indifferens)