check out sponsors out.(upper right hand corner) one of them sells flies. Also. the phoenix worms turn into soldier flies. You can buy those at Coastal Silkworms or Mulberry Farms
ive found pheonix worms, (also known as calci worms) at petco in little tubs.
I forgot about them for a week or so while moving a bunch of stuff, then when i found them again, and opened th container to feed the 'worms' to my cham, they had all turned into flies and a couple flew out. scared the crap out of me. but my cham loved them, chomped them the minute they entered his cage.
In contrast I have found the females to quite enjoy their food and they will overeat and become obese if you let them. I fed my lateralis majors 6 bugs every other day and they maintained a good healthy breeding weight. I never found mine to like soft bodied bugs like silkworms but they did relish the crunchy insects like roaches, crickets and flies.