Mealworm diet?

My salamanders seem to refuse crickets, so I tried feeding them some mealworms - success! The largest of the group pounced excitedly on the squirmy prey item. The others showed definite interest in them and almost took, but seemed to shy away. I grabbed the very smallest worms from the container and they dined well!

1) Can I feed them mealworms almost exclusively?
2) Is there away to make them more partial to crickets?
3) Would it be okay to keep a shallow feeding bowl inside of their enclosure?
3) If not, should I just let the mealworms etc. crawl about in their cage?
(I prefer not to do ^ this ^ because the worms tend to burrow and may not be easy prey)
4) Is 'container feeding' stressful?

Thank-you all, and sorry for all of the questions!

Unfortunately mealworms are rather nutritionally poor. That being said if mealworms are the only food your animals are accepting don't stop offering!
Earthworms are the best food for your salamanders. Try looking for them in a chemical free area if you have any places like that near you. You can also purchase bait worms but these are large worms that will need to be chopped into small pieces and offered on the end of a toothpick (if the pieces no longer move).
I don't really know of any way to encourage salamanders to take crickets but I have gotten shy new additions to eat by offering flightless fruit flies and white worms in large amounts. I keep poor eaters in simple set ups where the live food cant burrow away and I can more easily monitor my animal. I like plastic shoe boxes with moist paper towels for substrate and a few wet leaves for hiding spots.
I would not let the mealworms loose in the enclosure if they can burrow away. Keeping a shallow feeding bowl should be fine as long as the sal can easily get out. You may even want to partially cover the feeding bowl so it seems more inviting and secure/safe to the salamanders. They may even be trained to accept many different food items if they recognize and learn that that bowl means dinner!
Hope that helps a little and good luck with them
Heather

Refrain from mealworm as they have low vitamin and contain fat , they also are hard to digest so as crickets
Try earthworms instead as Heather said