How soon do you plan to use it? First good frost will take care of them if you don't need it right now. If you need to use it sooner then add some carbons to the pile first, let it dry a bit more, and give it a couple of days for them to move on.

You may not smell any odor but the flies have better noses. ;) So something is attracting them to it would be my guess.

Dave

You wrote:
" it seems like it would be harmful to my garden/plants if i spread compost with live larvae living in it..."

No need to worry. They eat dead stuff, not live plants.

Contrary to many others I do not believe the presence of fly larva in the compost pile at all beneficial. That they are there indicates your compost is too moist, because these wee buggers need a very moist environment to grow in. Some large cattle operations do use fly larva to aid in digesting the large volumes of manure the produce which alos helps reduce the volume of that manure.
The presence of fly larva in a home compost ple is a sign of a problem, the compost is too wet.

I've been told they don't harm plants. And they are usually long gone before I ever use the compost.

My compost is on the dry side, and I still get BSFL, so I don't think its too much moisture.

In my (mercifully) limited experience, BSF larvae make compost wetter. I.e., they're the cause, not the result.

(Bill_G, if you're there, we miss you.)

All fly larva need very, warm, moist conditions to hatch from the eggs, they are a symptom of a problem not necessarily the problem. The presence of fly larva, or other visible insects is an indication that your compost is too wet.

Is there an echo in here?

This says they like "moist". Which is what compost piles are supposed to be, too, no?

Here is a link that might be useful: Black Soldier Fly from NC State

I've noticed that my bins are often writhing with incredible numbers of these beneficial critters in the summer, but as it gets colder, they leave by themselves. You don't need to do anything to make them leave or to control them.

BSF larvae are not like other flies. These critters spend most of their lives as larvae, eating the stuff you put in the compost pile. In the fall, I've seen them leave the compost bins en masse to pupate, around the time of the first major rains around here (Oct/Nov). The "fly" part of their life cycle is insignificant -- they are tiny black flies that are innocuous and do not eat. Their only purpose is to lay eggs in a compost bin and die. They are not in any way harmful at any stage of their lives.

So if you put out compost with BSF larvae in it, they will not harm your plants.

The larva of any fly, black soldier or the common house fly, need the same conditions to hatch and grow in, moist. Those conditions are too moist for good compost digestion and like the common house fly these adults fly around and lay eggs anywhere and people have been known to ingest some. At one time advocates of these wee buggers stated that the adults helped control insect pests but since the adults "do not eat" they then serve no real purpose except as a food source for other critters and since the larva need an environment that is too moist for good comost digestion the presence of the larva in your compost indicates it is too moist. Fly larva do not belong in compost.

Do you still have a ton of SF larva in your pile, and would you be willing to part with some of them? Please e-mail me.

Thanks
Michelle
dragon_tears_inc@yahoo.com

kimmsr, you basically said the same thing three times in this post. Of the twelve posts on this thread, 25% of them are by you repeating the same thing. Why do you feel it necessary to repeat yourself?

Compost is supposed to be moist. The common recommendation is moist as a wrung out sponge. Not wet, not damp... not dry, but moist.

What is your experience with BSFL? Did you get them when your pile was too wet?

I can agree that BSFL are not necessarily a good thing, because they are gross... but are they really BAD for compost... not really. Perhaps one could manage their pile on the dry side and minimize the presence of the larvae... but the larvae are not going to harm the compost or harm the plants.

Because that apparently needs to be repeated, often.

Black soldier flies here in California are big. Close to an inch. They look like the first google image hit.

The larvae are regular visitors to my compost, and they're probably more prevalent when the compost is moist, but I still get a couple when it is not as moist as I would like. I read up on them at one point, and was informed that they emit a pheromone that keeps other flies away. Since then, I have not been bothered by them, as I think of them as a fly repellant for other species.

repeating a point, doesn't necessarily make it come true, nor does it convince anyone else that is... unless you are wearing ruby slippers...

Here is some info found in the vermicomposting forum by a worm expert. It really doesn't solve this post but I think it is interesting.

Posted by Kelly_Slocum sw WA state (My Page) on Tue, Sep 13, 05 at 11:53

Adult BSF are actually poor flyers, which is a good reason to be concerned about your nose, Chuckie. When they are flying around my compost bin I will often "walk in to them" and one or two will simply sit there on my shirt, seemingly quite comfortable and appreciative of the ride. Slow moving, BSF stop to rest frequently and are easy to pick up, unalarmed by human contact. They positively preen themselves for the camera! If you want a critter to photograph (other than tarantuals, which will legitimately pose for the camera) the BSF is an excellent candidate!
As I have taken a few days off from work I've been taking the time to cruise around a few web sites and see that, once again, the old myth that BSF larvae compete with worms for nutrient in the system is once again being erroneously circulated. This, as most of you here some to understand, is INcorrect! BSF larvae feed on raw OM while worms ingest the material in the bin only after it has begun to rot. BSF larvae manure is an excellent nutrient source for worms, since the larvae fragment the raw OM with their powerful mouth parts, processing it into small-particledm biologically amplified larvae poop, which is readily ingested and stabilized by earthworms. The combination of BSF larvae and worms makes for an extremely efficient waste processing system.

I've also read some statements that BSF larvae manure is as good as worm castings in terms of plant growth response. Not only has there been NO research to suggest that these statements are accurate, they are utterly refuted by the fact that BSF larvae manure is not a fully stable material!

I've worked on a few BSF waste processing systems, two of which were designed so that raw waste (usually hog manure) was processed initially by the BSF larvae, the poop from which (pretty liquid-y stuff) was stabilized by earthworms. These are remarkably efficient systems that process massive volumes of material each day and render the smelliest waste materials essentially odorless in just a few hours. I cannot emphasize enough the benefit of these flies or their suitability for working in conjunction with earthworms!

Kelly S

Kelly, your post seems to refute your previous post(s).

The last line reads, "I cannot emphasize enough of the benefit of [black soldier flies] or their suitability for working in conjunction with earthworms!"

That would suggest that BSFs *do* belong in compost.

Bruce--Kelly didn't actually post that. Kimpa posted it, quoting Kelly. It was Kimpa's first post in the thread.

Anything that helps break the compost down is fine with me in the pile. If pigs were smaller, they would be welcome too!

These issues are all about semantics and emphasis and how much control you have over your compostables, and how much time to spend balancing them.

It's a problem if it bothers you too much. It's not a problem as in, it's not necessary for you always to maintain SF-free compost. You can have fewer soldier flies if you have drier compost, but really compost that is more balanced via wet/green and especially less kitchen vegetable matter (i.e., I don't see the SF larvae going after "wet" brown leaves so much as liking old potatoes, fruit, etc). If you worry too much about perfect compost, you sometimes have no compost or less compost.

If I have a choice of adding "browns" or "greens" and I have a lot of soldier fly larvae, I mix in browns preferentially and add little extra water. I recognize that at that point I don't need to go out of my way looking for rotten fruits & veggies to add because they will love that. however, if what I have that day or that week is "green" and needs to get out of my house, I add it anyway (rather than putting it out for the garbage collection) and don't worry.

It all works out.

Constantly saying it isn't a good composting method doesn't make it true either especially when the end result is good compost. I don't mind having them in my compost bin during the warmer months at all and they help get the job done. If the pile is on the wet side, add some browns if you like and turn it. Big ---'n deal!

Sorry to address what seems like a touchy subject, but...I opened my compost today to mix in my garden and it was full, and I mean full, of black larvae. Some were moving and some appeared dead. I could not bring myself to use the compost with so many critters in it. Do I just wait for them to die? Or can I add something? I thought I was doing my compost correctly!!