Mealworms are high in chitin and should not be feed to young dragons at all due to increased risk of causing impaction. For dragons over 10" long, a few mealworms are fine for variety. Superworms are a better choice as they do have more 'meat' per body ratio than mealworms. However even superworms should be fed in moderation as they are also high in phospherous.
waxworms are completely different from mealworms and superworms but they should not be fed frequenly either, because they are high in fat. Waxworms are also very high in phospherous and a high phospherous count isn't good for bearded dragons.
Better worms to feed your dragon are silkworms and butterworms. Both are high in calcium, low in phospherous though they are a bit higher in fat than crickets and most roach species. However their soft skins, high calcium and protein content make them great feeders for growing babies and breeding females. For non breeding adult dragons, silkworms can be a regular part of their diet, but shouldn't be fed in excess as they can cause your dragon to gain weight (but not as bad as feeding waxworms exclusively)
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PHLdyPayne