Considerations for maggots in compost bin

Our community began an organics composting program, and we participate. We put our compostables in paper bags. At first, the proliferation of maggots (which we presume to be fly larvae) was off-putting due to being socialized to associate them with death and dirtiness, but we got used to them. We appreciate composting instead of sending our organics to a landfill and so consider them part of the process. At present, we don’t try to deter them. We choose not to put food waste in separate, sealable compost bags due to cost and inconvenience factors, but we could consider different choices based on additional facts, and our feelings and needs.

After the bin is emptied by the organics recycler weekly, in summer there are still dozens to hundreds of the white, worm-like larvae remaining in the bin bottom and clinging to the sides. To prevent odor and food build-up, we rinse out the bin after the recycler empties it, and this washes the larvae into the street and/or into the storm sewer to the local watershed. Considering options of what to do with the larvae each week is our interest.

  • We could leave them be: Not sure how they fare on the days after our compost bin is emptied by the service and there is no organic material in the bin with them for a few days.
  • We could collect them from the bin (they are relatively easy to empty en masse before washing the bin) and do something with them, such as:
    • Relocate them within our yard
    • Put them in a feeder for the birds
    • Or keep washing them out of the bin to the street and/or local watershed

What are your ideas or what are considerations you find compelling? How do the organisms (in larval state and as hatched adults)-- and our actions–affect the yard? The organics recycling program is not mandatory and 50-70% of our neighbors participate. We will probably make an iNat observation of the larvae next summer, now that we are learning to tolerate and appreciate them more. Thank you for your interest.

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It really depends on the type of larvae. Calliphorids feed on dead stuff. If you leave them in the bin, they might find enough food to pupate and emerge as flies. Leave the bin open so they can leave. If they are some other type, like root maggots or fruit flies, it might be harder for them to live. Both of these are fairly small, so I’m going to assume they are the former, rather than the latter two.
Maggots have a bad rap - they kind of creep me out, especially inside the house. Although, maggots are very good at cleaning out human wounds. They only eat dead tissue, and secrete some sort of anti-bacterial substance.
A little story - when my kids were young, there was a bad smell in our small house. I searched all over for a discarded diaper, and eventually deduced that something had died in the walls of the house. Since I was not inclined to rip the walls apart to find it, I decided to let nature run it’s course. Eventually the smell went away, and suddenly the house was populated by flies, which presumably were the result of maggots on the dead whatever it was.

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I don’t know where you’re located, but for me in southern CA compost bin maggots are usually black soldier fly larvae (stratiomyidae). If you’re dealing with those I wouldn’t worry too much, any of those options would be fine.

If you leave them be they may not survive, depending on how quickly new compost is added. If they die they’ll be another ingredient in the compost. If they live they’ll have a head start on doing what they were going to do anyways, which is breaking down the organic matter.

I think it would be tricky to relocate them and have them survive, but if they die they will not be wasted as they are a good food source for all kinds of things. Birds would certainly enjoy eating them, whether finding them in the yard, in a feeder, or wherever the storm system takes them.

The adults are large and interesting looking, they can be mistaken for a wasp by some people but they are totally harmless and IMO very beautiful. They would have no negative effect on your yard that I can think of.

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I know of systems that use black soldier fly larvae to compost organic waste, and then the larvae are fed to chickens, whose waste is used to fertilize crops. This is a more or less closed cycle and people can eat many of the different steps along the way.
https://www.inaturalist.org/observations/62102601

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No one has mentioned eating them! We all should increase the proportion of insects in our diet as they’re the ultimate sustainable animal protein.

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yeahh, I couldn’t agree more, they can also be used as diet for fishes and duck in poultry farming.

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if your compost bin is getting emptied and cleaned weekly, i’m thinking those flies would either be house flies (common or lesser) or fruit flies or something similar. soldier flies are always nice to have in compost, but i think they would take more time than you’re allowing to develop to a size where you’d notice them.

if you’re washing your compost bin anyway, i would just continue to do what you’re doing. that’ll prevent the flies from pupating in your bin. i doubt that any birds would be interested in week-old larvae (although some birds might be interested in the adults, if you took the extra effort to raise them to adulthood). i doubt the larvae would do much to help (or hurt) your yard other than contribute a tiny bit of organic matter to the soil when they die. maybe things like ants might eat them though.

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I don’t know about your local municipal regulations.

We are in a coastal suburb, and they had to remind the supermarket NOT to wash garbage bins into the stormwater drain … and straight onto the beach where families are swimming and kids digging in the sand. Blue flag beach? Water quality?

That contaminated water should either go to sewage works for treatment. Or into the garden for nature to process. In Cape Town.

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Thanks for bringing this up! What are potential implications to the watershed if everyone who composts organics rinses the bin into the street that drains into the storm sewer and the local pond/creek? We were thinking that since it was an organics compost bin that it was safe, but maybe it isn’t. This is organics compost (not yard waste) that includes mostly food scraps and compostable paper products. Washing that into the storm sewer also sounds suspect. We checked municipal regulations and didn’t find anything. So we are going to email the composting program and the local watershed to obtain guidance.

In the meantime, this advice seems like a possible route for our compost bin rinsing:

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i recently saw an instagram page of a company that grows soldier fly larvae to feed to reptiles and chickens, and they feed them compost. It sounds like the soldier flies are beneficial, though for sure if the compost is kept inside you may not want the adults all over the house. If it’s outside and they aren’t biting or invasive species, i say embrace the maggots.

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yeah… our garbage bins are in an alley way. If we were to rinse them in the alley, the water would run straight to the nearby lake. An iNat user has been working for years to get changes made to the water that empties into the lake. By his account, 928 acres of street storm water is emptied into this lake.

Earlier this summer, Sean marked a green ball and dropped it into the storm drain near his house. Two weeks later, he found that ball floating in a mass of trash and other debris near the storm culvert at the north end of lake.

https://www.pca.state.mn.us/featured/trash-exhibit

I’m sure it’s not quite that dire for everyone. We have lots of lakes and reclaimed marshes here and the water has to go somewhere when it rains so it naturally seeks out the low areas. But I would think rinsing it out where the water drips into the soil would take care of maggots.

For what it’s worth, we have city compost pick up and we put our kitchen compost in paper bags (from the grocery store). We’ve been told it will compost down and it keeps the compost (from our kitchen) off the bottom of the bin. Ours is picked up once a week. Those compostable plastic bags were worthless and expensive.

by the way, observations made at iNat have been very helpful to document the biodiversity of this lake:
https://www.youtube.com/watch?v=7Ux73bJUWAA

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If it is emptied weekly, I guess more material gets added daily or every couple of days. I’m sure the maggots won’t starve before the next food arrives. However, they may go looking for some. If they climb out the bin, will they be a problem?

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This thread title reads like the title of some odd poem. Perhaps by a Vogon (from Hitchhikers Guide)

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Considerations for maggots in compost bin

Born of discarded food
Scorned and vilified for their existence
Rinsed into the street to become food themselves
Or desiccate with the inexorable summer asphalt.
At night, with a warm cheek upon a cold pillow,
one thinks to hear the cry, “Charlie! Charlie!”
from the street below.
“Charlie, Forum Moderator and literary critic!”

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I don’t think one would need to worry about compost and insect larvae in the storm sewer. When it rains, dog and cat feces (and wild animal feces) enters the sewer also. That sewer empties into a river or lake. Additionally, from all across the countryside, wild animal feces (and that of cattle, hogs, chickens etc. on farms and ranches) drains into those same rivers and lakes. Waterways and reservoirs aren’t sterile places, and the scale of organics from compost bins compared with all the other organics is minuscule to say the least.

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:laughing: hahaha

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If you live near agri-chemical and feedlot runoff - who cares about bin rinsing.

If you have a blue flag beach. Or - like New Zealand and UK - you are campaigning for rivers that are safe to swim in - then do try to keep your stormwater drain for … rain.

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Yeah and if you have any planters or lawn rinse it in there and make the plants happy

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Isn’t Vogon poetry considered a form of torture in most of the Galaxy?

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Ahhh. I mis-interpreted the original compost source as a garden composter. I think all that needs to be said has been said!
Winnipeg does not have a composting program for some reason. I just throw most of our plant based organic waste onto my small garden. I’ve been doing it for years, and it seems to break down just fine. Our winters help. It’s always interesting to see what volunteer plants come up in the spring. Often they do better than the seeds I plant.
Also, the city does not remove fallen leaves from the streets. They get mushed up by cars, and washed down the drains, which I believe exit to the Red River. Private homes have the option of bagging yard waste for pick up.

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