Nice little dragon 
It is both true and untrue that you can stop feeding crickets at 6 months of age. It is untrue in the fact dragons that age are still growing and need the protein and energy they can get from crickets.
It is true (somewhat) that you don't need to use crickets at all. However, you still need to feed insects of lesser amounts as the dragon ages.
Healthy feed every day (or several times a day depending on age) insects other than crickets are: several species of roaches (for large adult roach species, the smaller and softer young are best to feed, use the same space between the eyes size rule with roachs as you do with crickets), silkworms, butterworms, phoenix worms (these are new in the market, haven't yet had a chance to research them for nutrition content and overall suitability for bearded dragons. They are basically fly larvae, like maggots), hornworms (captive bred ones, not wild caught...wild ones are toxic!), and superworms. Mealworms and waxworms can also be fed but sparingly and no mealworms to very young dragons (probably best not to feed mealworms till your dragon is at least 10" long and only small numbers...6-12 at the most at a time)
Once your dragon reaches 14 months only a few insects a day is required (typically no more than 10% of their daily diet as insects). A couple silkworms one day, supers another, some butterworms etc...gives a good variety and keeps your dragon interested in what his next insect meal will be and also helps him being picky.
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PHLdyPayne