Forgot to mention they're about a 1/2" long. (and I think that was a cantaloupe rind.)

Black Soldier Fly larvae I'd say, happily breaking down the compost.

tj

In the thread "What is this in my compost bin?" (see link below), we've been talking about these same larvae.

There are Black Soldier Fly larvae, which I've learned are even more effective for vermicompost than red wigglers.

Here is a link that might be useful: What is this in my compost bin?

A fly maggot for sure, whether it is the larva of the Black Slodier Fly or the common house fly or the stable fly or one of the others is difficult to tell since they all look very similar. Maggots need a fairly moist environment and a good source of protein to exist so their presence can indicate your compost is too wet and has some Nitrogen that needs to be covered.
While some CAFOs have used the Black Soldier Fly larva to digest their manure piles since the adult BSF does nothing except look for another BSF to mate with in its short 30 day life there is no real good reaon to have them in your compost, especially since most of us cannot tell the difference between the various fly species until the maggots are much older.

The biggest difference between the larvae of Black Soldier Flies and those of house and stable flies is the smell. BSF larvae secrete digestive enzymes that help them digest their food. These digestive enzymes help prevent the growth of anaerobic bacteria that other fly maggots depend upon to help pre-digest their food. These anaerobic bacteria are what produce the "stink" associated with them. If you've got BSF larvae, it probably doesn't stink, and if it stinks then you've got disease carrying flies.

Even when my compost pile has perfect amounts of water and air, and it's hot inside the pile, I often find BSF larvae eating cantaloupe rinds on the surface of the pile. I'm a vegetarian and eat lots of fruit. Cantaloupe is one of my favorites, so I have lots of cantaloupe rings and seed 'muck" that I throw on my pile. I find that the cantaloupe seeds are one of the few seeds that will often sprout after high compost temps. For this reason, I like to leave them on the surface of the pile to go ahead and sprout. Once most of the seeds have sprouted, I turn the cantaloupe seedlings under the compost.

Because the cantaloupe rinds are very wet, I also leave them on the surface in the sun to dry out so that my pile doesn't get too wet. These cantaloupe rinds are the main thing I ever see the BSF larva eating from my compost.

I have a compost bin filled with these flies. I love what they are doing in my compost bin but am worried about spreading the compost on my garden, will they eat my plants when I plant them this spring? I don't think they will all die over the winter because it is generally above freezing.
Thanks!

Those maggots digest decaying vegetative waste and if they are the larva of the Black Soldier Fly the adult flies do not eat anything for their roughly 30 day life, all they do is mate and lay eggs to produce more maggots. Since most everything I have seen about these maggots in compost says they indicate poor management and really do little worthwhile they do not belong in your compost.

BSF larvae eat raw food waste and then they poo. IMO, BSF larvae poo makes good compost.

My pile is typically very dry and I still have them munching away on food scraps fairly regularly.

I have read that other flies stay away from where the BSF's are. If so, they could be useful in that respect. I have seen special BSF composting bins for sale. Never tried it but sounds interesting.

BSF is poor management??
I have spread manure on fields for 40 years in sheet composting.
I have had a compost pile for 32 years. We have always believed that all worms helped the process, not just the redworms that have become hip in the urban renewal of the last few years. Farmers have used animal & plant waste for
thousands of year, we get a microscope for a hundred years or so & we know everything.
To each his/her on, but I say more the merrier.
If it does not bite me or my vegetables, let it live.
Happy Holidays everyone.

If you are looking for a consensus, I agree with black soldier fly ... and ... YAY! It's a good thing.

YES@ these look to be BSF larvae, in addition to being voracious eaters of decaying plant material, they are also about 50% protien, as the adult of the species does not have a mouth and cannot eat, they need to be able to sustain the fly for its 5 to 8 day life so that it can breed. these guys do not harbor bacteria, and are DEFINATLY a GREAT addition to your compost!

Here is a link that might be useful: Mad River Seeds

"voracious eaters of decaying plant material"

They are eating your compost up, it is something to consider, how much compost to you want to end up with at the end of the process? Maggots are bad, they eat way more the worms, if worms do eat compost, it's not very much if they do. If you don't care about how much compost you get then, no problem, expect they are gross when you have to deal with them.

I have started a worm bin out of a plastic container using rabbit poop, shredded paper, and coffee grounds with the filters. I have read where maggots are ok and where maggots are not ok. My bed is moist but not too moist. I have added more rabbit poop and paper but the maggots are still there. I have been taking them out and feeding the maggots to my chickens. How do I keep the maggots out and the flies? I put a bowl of water with dish liquid in my bin but the flies and maggots are still there. My worms seem to be doing ok, what do I need to do?

Worms don't eat compost. They eat garbage and help make compost. The same for maggots, whether of horseflies or soldier flies or any other socially unpopular fly. Don't forget the roaches.

Just a few decay paths among zillions happening all at once.

Breaking down plant matter is not the same as propagating pests, but they are linked. A compost pile is full of an uncountable number of different beasties and to say they don't belong in the decaying pile is naive. The pile or bin is where they DO belong.

PS: disease carrying flies? Name one person who caught a disease from a fly in her garden. Just one. And don't use the Internet as your source of (mis)information.

If there are maggots in your compost, either you're putting something in there that you ought not - such as cooked foods, bread, meat, or bones/blood/guts - or its not hot enough. Or both.

Turn the pile. Figure out why it isn't cooking properly. Too dry? Not enough greens? Too wet? You've got it in the shade so it can't heat up?

And if you've been putting cooked food, meat, etc etc in the pile - stop.

Posted this 4 yrs ago when I first started getting serious about composting. I've got 2 tumblers going now - well, one is just the bin from a tumbler that someone put out for trash.

Tons of black soldier fly larvae doing their best in the "fresh" pile right now. In the other bin - the one that actually tumbles - is last winter's compost that sat through the summer. I turn it once in a while and just opened it up today and was surprised to find some red worms in it. How did they get in a tumbler??

If you want less of those maggots, just keep the lid on the compost, keep flies out, compost fruit before it gets rotten, if you go out daily and clean up dropped fruit instead of waiting for like a month or so it will have much better outcomes. It is a timing thing.

I stopped putting any kind of food in my bin. When I go to check my bin there is moisture on the lid and sides. I put my hand down in the bottom of bin and it is warm. Can it get too hot and kill my worms?

Beavers, it might have been better to start a new thread for this question which is not really related to fly larvae. In any case, unless you are specifically trying to have a Worm Bin (vermicompost), you should not have to worry about this. Mainly because Earthworms are not the only or even the main critter that converts organic materials to compost. All kinds of microbes and a few insects do most of that work. True, you will not see worms in a hot pile, but the heat is there because the pile is rapidly decaying. If it's too hot, worms will gradually exit into the ground since they are constantly seeking their ideal temp and moisture conditions.

Food scrap is an excellent compost ingredient when properly managed. I would encourage you to continue composting it.

What I dont understand is, if the BSF worms eat the fruit and other compost foods I put in there, then why wouldn't they eat my plant roots when I use the compost?

They eat decaying material. Since your plants/roots are alive they do not show up on the menu.

great to hear! Thank you!

It's analogous to the different kinds of birds. Some eat seeds, some eat bugs, some eat mice and rodents (hawks and owls), and some eat dead animals (vultures). I would not worry about putting my pet hamster near a sparrow, but a hawk, no way. :-]

What an enjoyable thread.

Now I know why I sometimes have those maggots in the compost bin. And it all makes sense. For it is only sometimes that I put cantaloup (rock melon) rinds in there.