lol..
Excuse my stonedness, please
After rereading your comment, I think the answer your looking for is the Gnatrol poison or Gnat-Nix bad for the plants?
Answer - The Gnat-Nix is just tiny glass lava rock that is like a field of razor wire to the bodies of soil dwellers and is inert and totally safe as long as you do not get it in your eye ( recommend stopping area fans while handling)
Gnatrol - I guess it can be if overused, but as directed, not from what I have read ( I do not use it, just the top dressing and sticky pads)
Peace
Asmallvoice