Successful fungus gnat traps - DIY project

[Leafmite]

Rosie, it is because of one of your posts recommending them that I bought a butterwort. I really love them! I grow a theobroma cacao (chocolate tree) that likes to sit in a pan of water and stay moist. The dirt is a breeding ground for fungus gnats. I never see them, though, except when I look at my butterworts. My butterworts bloom year round because of the good food!
I have a purple pitcher plant and there is always something floating in those murky depths....