Just cover the surface of your bin with 1" of soil or compost or (my fav) a few inches of shredded paper. This will keep the flies from getting to the fresh scraps, where they feed and breed. Adding shredded paper to the mix will dry things up a bit too, which helps.

Try to cover your vent holes with fine mesh as much as you can.

I have hung fly tape when it got bad it seemed to keep things in check

Put about a half inch of cider vinegar mixed with an equal amount of water in a small-necked bottle (like a soda bottle) and leave it near your bin. It will attract a lot of flies, who go in there and die.
It won't stop them from procreating, but it has an advantage over no-pest strips because it is not poisonous, and it has an advantage over fly-paper strips because it won't get caught in your hair.
mbetts
p.s. My friend Timmy suggests that when I catch enough fruit flies I can just add a little olive oil and maybe some tarragon or something and I will have delicious Fruit Fly Vinaigrette.

mmmmmm ... now that's recycling gone wild.

Mbetts, these aren't fruit flies. The ignore fruit fly traps.

Try vacuuming them up- ervery time you open your bin, stick the vacuum nozzle into the smarm of flies. It reduces the adult numbers and after a week or so, if you do it every time you open the bin, you should have got rid the new hatched flies too.

I have been vacuuming them for weeks, and they just get thicker. A lot of the will crawl around in the bedding, so the only way to vacuum them up is to vacuum up the bedding. I don't have a swarm flying around when I open the bin. A few will fly out, but most of them stay in the bedding.

Fungus gnats are very small and similar to fruit flies. I've read some posts on the use of beneficial nematodes to kill the larvae. Seems pretty effective but haven't tried it personally.

Nematodes haven't helped. I'm wondering if what I have is something other than fungus gnats. These are bigger than fruit flies.

Kind of a puzzle if not fruit flies or fungus gnats. Indoor bin? Maybe it's time to go a little step further and maybe turn the top layers under to the bottom of the bin and stop feeding for a while. If the larvae feed on the surface material it will put it out of reach for new flies and possibly be unsuitable for new larvae.

Indoor bin, but I grab food from outside sometimes. I think the flies came in with some horse manure I picked up on a horse trail.

OK, I'm experimenting. Day 1: I moved one of my bins (I have two) into an unused bedroom this morning. I put up a No Pest Strip in that room. This evening some of the worms are crawling. It could be because I don't have the heat on in the bedroom, I can't tell. This does not look like a stress related mass exodus, but it is a lot more worms than normal crawling up the sides of the bin. The worms look healthy. The floor is peppered with dead flies. I can only see one fly on the ceiling. There are no other flies that I can see on the walls or flying around. I can see a few flies still in the bedding.

So far, so good.

I'm only doing this with one bin at this time in case the worms react negatively. In order for this to work, I will need to keep the bin in the same room with the No Pest Strip long enough to kill any flies that emerge from eggs. I am hoping that two weeks is long enough.

Day 2:

I have moved my second bin into the bedroom. The worms appear to be fine. The flies are dropping like, well, flies. There are still a few flies crawling in the bedding. Everything looks good, except that I will need to vacuum every horizontal surface in the room when I'm done with this,

if they are slow and dusty when smashed, i think you may have drain (moth) flies.

Day 3:

The floor is littered with dead flies. There are few remaining in the bins. They may be new hatchlings. The worms are doing fine. I see no sign that they dislike the No Pest Strip.

sbryce,
Have you tried covering completely the top of the bedding with something.....like an old cotton t-shirt? The t-shirt would still allow for airflow, but it might suppress whatever type of flies you have.
Beth

They are fungus gnats. Have the exact same problem and have been dealing for about 3 months. Sorry to hear you have the visitors too. Best remedy I have to offer is good for houseplants (thats' where my worms reside) I put a layer of construction sand (~2" deep) on top of the soil. Hasn't gotten rid of the gnats entirely but sure helped. Before that I tried the vinegar, sliced potatoes (a big mess that made), and fly strips. The sand is the only effective move I've made so far...apparently the granules slice the larvae which is why the weight of the sand is important. Don't know if that's a help for a soil worm bin (which I have acquired from the old potting soil as I had to re-pot every plant) and while I relocated most of the worms I could find - there is no way I got them all. I'm still looking for a magic way to separate worms (the babies too) from the old gnatty soil so I can get tid of it altogether. Of interest thought, the gnats do seem to go for the yellow colored "Sobe" energy drink? Like they need more energy! Drink up and float you annoying and destructive little pests. What...so bitter? Bloomin' Gnats!!! For the record I try to never kill any insect - ever; but they eat the plant roots and nearly destroyed several plants entirely in doing so. Just glad they don't eat people:)

We use the sand for our inside plants and it works like a charm. I don't think that it is necessary for a worm bin though. On another forum a member there was having problems with fungus gnats. I recommended the cotton t-shirt to cover the entire top. He said that it cleared up his gnat problem in three days. Our bins are larger so we cover them with burlap and an inch layer of dry shredded newspaper. We do NOT have any gnats.

Careful with the sand. I used a handful of construction sand to mix my carrot seeds and toss into a bin this fall. It seems to have "poisoned" that planter. I'm going to have to dig out the top layer of soil and replace. All my other bins are growing great except the one with a handful of sand. The few carrots that germinated are barely alive.
Not the seed as tried same seed again in a different bin and they are doing fine.

tracydr,
Thanks for the warning about using construction sand. Glad you brought it up. I purchased the sand from the garden section, so it must be different and our plants didn't have a problem. I also don't recommend the sand for a worm bin, but it worked great for our plants.
Beth

It sounds like you've got a fix...but here's another idea if not...

I had some kind of weird flies for a while. I got rid of them with a combination of bedding and traps.

First I put about 3 inches of dry shredded paper completely covering the top of the bin.

I also made traps as follows: take an old plastic container (yogurt, peanut butter, etc.) & throw in an apple core; take a piece of paper and make a cone shape out of it with the base diameter being greater than the diameter of your container; cut the tip off leaving about a 1/2 inch diameter hole; put the cone tip down into the container positioning the tip about an inch above the apple core; tape in place - making sure to tape the entire edge of the container to the paper.

Place trap(s) near the worm bin and/or in any other area that the adult flies seem congregate...which for me was in my kitchen and near my eastern facing windows.

The flies fly in to get at the apple and can't figure out how to get back out. You can see them flying around and around.

Dispose of the the flies/apple/trap when full or no longer needed.

Hi, smgale. These files are not attracted to traps. I have already tried.

It has been almost a month. The No Pest Strip has killed almost all of the flies. The trouble is that the No Pest Strip has killed ALMOST all of the flies. If I take the strip down, I am likely to have a major fly problem again in no time. I was hoping I would only have to do this for a couple of weeks.

sbryce,

Have you been able to identify the type of fly you are combating? I just skimmed down your thread and it looks like the consensus is that you have fungus gnats but there still seems to be some question. Knowing your enemy is the only way to win. The No-pest strips are a broadside attack on them and will keep numbers in control but you need a surgical strike to finish the battle.

First off is tilting the conditions of the bin in your favor as to make it less hospitable to flies. I find most flies like moist conditions so let your bin dry out a bit and stop feeding it for a few weeks. The worms can last a lot longer then the flies on bedding only. Cooler temps will also slow down the flies reproduction rates giving you another advantage.

Where did you purchase your nemetoads from? It may be worth it to order a new batch online. They are a living organism and if they had been sitting on a shelf for months or got to hot and transit just one time then that batch is DOA and you would never know. This is also true of BTi and Spinosad insecticides.

When I first started my bin I had swarms of fungus gnats and found one treatment of nemetoads knocked out a majority of the population within a few days. A follow-up spraying a week later took case of the problem. I have not have a fungus gnat problem since. I am convinced the nemetoads are still in my bin and are spread throughout my houseplants as I top dress with my vermicompost.

I hope you get things under control soon as flies are a huge pain. Let us know how it goes and keep up the attack.

Good Luck,
Mr Ed

I don't know what kind of fly I have, and I wouldn't know how to find out. Since they aren't attracted to fruit fly traps, I would guess fungus gnats. The nematodes were ordered on line from Home Depot. The brand name is Ladies in Red. I have inoculated the worm bin twice. I may try again.

sbryce,

Can you collect some of the dead flies and take a picture?

I ordered my nemetoads from Hirts Gardens on Amazon.com I think they were about $25 with the shipping.

Good Luck
Mr Ed

Recently I put on a blog post about fungus gnats on our website. There is a good photo of one there too.

Here is a link that might be useful: Fungus Gnats and Worm Farm Bins

"Our bins are open at the top. We cover them with burlap and an inch layer of dry shredded newspaper. Instead of burlap, you could use an old cotton t-shirt. This makes it very difficult for the fungus gnats to get to the moist castings and bedding."

What about the fungus gnats that are already in the bedding?

I'll see if I can get a picture of one of my flies, but my camera does not photograph things that small very well.

Hi sbryce,
I think that the gnats need more access to the air. Not really sure, but what we are doing works as we don't have any gnats. Prior to using this technique however, we did. We also stopped using cardboard. I think that exposed moist cardboard is a perfect breeding ground for them too. Try it out for a week and and see what happens. I'd be interested to see if this works for you. I hope that it does. Did you look at the photo on my post?
Beth

Hi all,
I too am having a bug issue despite doing everything right (I think). I keep all my scraps covered by at least 2" of shredded paper and cardboard at all times, and I have drainage holes in the bottom of the bin so excess water doesn't accumulate. The bedding feels spongy and damp but not wet. The little bugs are EVERYWHERE in the bedding, on top of the bedding and all over the sides and the underside of the lid. I've looked up photos of all the usual worm-bin suspects and the bugs I have (in disgusting quantities in my bin and now also in my apartment) don't fit any of the profiles. I have a photo but am not sure how to share it. The bug in question is smaller than most of the fruit flies, with long black bodies and iridescent wings that are tucked under each other if that makes sense. They sort of fit the description of a black soldier fly except for their size. The information I have about black soldier flies is that they're a bigger insect than a fruit fly. These are a little smaller or at least the same size. They've overrun my bin and are escaping, which, beneficial or not, is a problem because I have a bf who is grossed out by any flying thing in our apartment. Can someone help me positively identify what they are first, and then help me figure out ways to control the population?

Jwilson,

Sorry to hear of the pest invasion. I think it happens to everyone at some point. First off, you may want to start your own thread since your pest may be different then the one sbryce has been fighting.

I think you can still get a snapfish account and upload photos there that you can then link to here or create an account on vermicomposters.ning.com/ and there is a photo section.

The most common pest that I have encountered is the fungus gnat. They are not a big concern but are very annoying. I would go up to Beth's earlier post as she posted a great picture of a fungus gnat on her blog. If that is what you have I recommend beneficial nemetoads as they worked very well for me. If you read up on this thread you will see lots of other suggestions. I also found a good article on fungus gnat control for your household as I think this gets forgotten and then an infestation in the bin comes right back.

Good luck.
Mr Ed

Here is a link that might be useful: University of Nebraska - Fungus Gnats

Sbryce,

I've had a couple instances of fly invasions over the past few years. The flies have always been fungus gnats, living and breeding in the soil I use for my houseplants. These are some pesky little critters for certain!

Here's how I solved my fungus gnat problems:
1) I add a thin layer of sand over the soil surface to my houseplants.
2) I use a type of carnivorous plant called a Sundew, which are easy to grow and propagate, and place them near problem areas. This plant is basically living flypaper, and will clean out fungus gnats like nobody's business.

For my indoor worm bin, I use fiberglass screen over the vent holes for the larger insects, and I've placed a trio of sundews around the bin. No fungus gnats (so far).

Fungus gnats could probably zip right through fiberglass screen, though. You might consider using landscape weed fabric -- it lets air and water through, but should keep the fungus gnats out.

Sbryce did you finally win the battle using the no pest strips? I have an infestation of gnats and I am considering trying the same thing as you.

The No Pest Strip killed a lot of the flies, but did not completely eradicate them. I finally bought some Hot Shot Kitchen Bug Killer (active ingredients: pyrethrin, piperonyl butoxide) and sprayed the bins lightly once a week for about 4 weeks. The flies are finally gone. I have not seen any flies in or around the bins for over a week. If I see any more, I am using the Hot Shot.

No adverse affects to your worms with the Hot Shot Kitchen Bug Killer?

No adverse reactions. Per instructions on the can, I sprayed very little. No adverse reactions from the No Pest strip either.