I think you would have to be leary of maggots. Almost by definition they represent higher bacteria counts. They nourish themselves on decaying organic matter, often where animal tissue and excessive moisture are involved, which would be to say that they thrive in conditions of very high bacteria, more than you would have with other insects, such as roaches and crickets raised properly, and they consume those bacteria in quantity. The transfer by such "poison pill" insects, i.e. those with unusually high bacteria count due to their own feeding/drinking sources, of high bacteria quantities to your chameleon has been documented to have detrimental, and often fatal, net effects on your chameleon. If the maggots were raised in a more sterile environment, where they were provided fresh feed matter daily, and all of the old was removed, then your risk would be greatly reduced.
The safe course, IMMHO, is to stick with those feeder insects where you can have the greatest control over what the bugs are eating. This rule would eliminate many of the bugs I often see discussed here as "variety", as you cannot gut-load them, nor were they gut-loaded by the supplier. On this note, unless you have reason to put great faith in your local pet store cricket source, to feed crickets recently purchased from such a source is a big mistake as well. You should have crickets in your keep at least three days before offering them as food. This will afford them the opportunity to "clean out". Good luck !
