I remember hearing that those fly "sticky traps" are not something that you want near a food product.
Try this ..
1) Wipe down and clean every surface in your winemaking area. The trick here is to have everything clean, clean, clean. You should not be able to smell even a hint of wine.
2) take a 2 liter soda bottle, cut the top 1/3 off to end up with a funnel shaped piece and a cup shaped piece.
3) pour some wine and a drop of dishwashing soap into the bottom portion (cup shaped piece) of the soda bottle.
4) Invert the funnel shaped piece (narrow end down) and insert into the bottom (cup shaped piece).
you end up with a fly trap, flies go in, but have a hard time getting out. they are attracted to the wine in the trap (the only food source since you cleaned every surface in your winery) and drown.
works like a charm!