fungus gnat / sciaridae attractors

[musihuto]

what sort of scents are fungus gnats (sciaridae.) attracted to?
i'm trying to design a non-toxic sticky death trap.
so far the cup with banana liqueur in it is not doing the trick!
i.e. they're totally ignoring it...

thanks!
- munis

 

[RVS]

A cup of wine worked pretty well for me.