Howdy Katherine,
Sometimes Panthers that get stuck on a food item may need to be witheld food for a week or more to break the habit. Once he shows interest in a new food item, you may want to try several different new items. If your Panther will take properly sized dubia roaches then definitely go with them too. Most chameleon keepers dream of findng a feeder as economical and easy to maintain as dubia roaches
. I've used crickets, silkworms, hornworms, dubias, superworms, butterworms, mantids, commercial house flies, and others.