If you can be certain that the insect was not exposed to any pesticides or chemicals that could be harmful or fatal to your chameleon, you could feed it.
What I use to do was keep the hopper contained for about 24 hrs and feed some fresh romain. Most of the time if they are exposed to a large amount of pesticides they will die, but if still alive feed away and make sure your guy is big enough. He will love it
