i've also had a recent fruit fly problem. however, i inadvertently left some strawberries out overnight in a bowl, and it seemed to have attracted most of them (they were remnant strawberries that were a bit gnarly and i didnt' want to eat). i quickly vacuumed the bowl, and the apt seems pretty clear now.

Malt vinegar is all I have at home and it worked great so far. Don't forget to add a few drops of dish detergent to break the liquid surface and cause the flies to drown. Others have used wine vinegar or cider vinegar and that worked too.

Beer with one drop of Dawn.

Thanks for the ideas. I have poured out the apple juice and replaced it with some strawberry trimmings. We'll see how it goes.

Two days later, I have caught 1 fruit fly. They are all over a sliding glass door. I think they are drawn to the incoming light. I vacuum dozens off of the door several times a day. That is working better than the trap.

sbryce:
you're sure you meant fruit flies, right? Not the smaller black flying things with smokey grayish wings: gnats. These will not get into the vinegar trap. These are the ones I've got on my windows, glass doors, sun roof and ceiling. In short, everywhere!

Since they don't seem to be very interested in the various baits, they just might be fungus gnats.

So, is there any way to get rid of them? I have been holding off on feeding the worms until they all die, but that might not work if what they are after is fungus, and not sugars in the decomposing fruit.

Maybe a hungry frog or toad in the worm box or next to the sliding glass doors?
The place would be like Wild Kingdom only with electricity.

If they are fungus gnats, the sell these yellow sticky traps that work really well. I bought mine from Gardens Alive, but shipping probably would take a week & you might go crazy by then. Maybe someone knows where you could buy them locally.

I have caught a lot of them on the hanging yellow sticky strips of flypaper. Are the traps something different?

We bought the yellow sticky traps at Ace and Orchard supply for white flies in the garden last year. The flies are attracted to the yellow color. You could make your own by using yellow cardboard and applying something sticky to it like vaseline.

No, I doubt the traps I have are very different from what you describe. Sorry. I wish I had another suggestion! Keep vacuuming--that seems to be the most effective method for me, too.

I had a fungus gnat problem last year. I purchased beneficial nematodes and after one treatment they have never come back.

I was told the nematodes continue living in the bin long after the treatment. I have had fewer pest problems on the plants I used my vermicompost on this year also so my theory is that the nematodes will continue living even in the vermicompost I harvest from my bin.

This means one treatment should give you long lasting gnat controls both in your bin and in any planter box you use your compost in.

I never had much success with the traps that use a sheet of plastic with holes poked into it. Or with vinegar as a bait.

But had very good results with a trap made of a plastic pop bottle. Drill three small holes in the lid. Cut off the top a third of the way down the bottle and invert it into the bottom. For bait I've used banana peal and apple core in mine with great success.

You can place these traps inside the bin just make a hole in the bedding and stand the trap up inside the hole.

As I mentioned earlier, I used malt vinegar that I had in my pantry for a long time (years?) and I have used it up now. I bought wine vinegar and made a fresh trap and ..... nothing came in although the FT is buzzing with fruit flies because of the fermented bananas I put in recently. There are so many of them (fruit flies) and flying in my face whenever I wanted to take a look.
Is the vinegar too fresh maybe, lol.

I think I am going to add a piece of banana in that trap. See if it will work better.

When I had a severe fruit fly problem I put a small jar on top of my bin with a 50/50 mixture of water & white vinegar plus a couple drops of Dawn detergent and I literally caught hundreds within a couple days.

But the traps are only a short-term solution. You have to have a properly designed bin system with most vent holes covered with fine mesh. Also, bury all fresh scraps well underneath the old stuff. Also, each time you add new material, cover the entire top surface with a layer of soil, shredded paper, or a solid layer of newspaper. Also, empty the tea regularly.