I totally agree with dodolah
VARIETY is important to the health and happiness of your chameleons. As many have said, You can feed yours a wide array of appropriate sized bugs.
I use: crickets, kingworms (aka superworms), Madagascar Hissing Cockroaches, Indian Walking Sticks (phasmid), silkworms, butterworms, Turkish Roaches, mealworms (yes, they're okay now and then - better if you breed yourself, and only offer freshly molted (white) ones as they're easier to digest), waxworms (treats only), hornworms (you would have to use small ones of course), grasshoppers, woodsows (aka pill bugs - and like mealworms these take longer to digest, so moderation is key), moths, etc.