Sunday, October 6, 2013

What's In Your Bin?

Last week I opened the lid of the compost pile to toss some coffee grounds in and noticed the surface of the pile was gently undulating.  I bent in for a closer look, and saw a layer of light brown maggots.


After thinking about it, though, I  decided the maggots might not be so bad.  The purpose of the pile is to break down the kitchen and yard waste; if the new bin tenants helped in the process, who was I to complain?

I started keeping a better eye on what was going on in the bin.  Amazingly, even though I was adding a lot of waste it looked like the compost level was going down.  A cantaloupe peel and seeds had disappeared by the next day, as did cooked vegetable scraps from broth making.  A paper coffee filter with grounds piled on top left in the bin today would be reduced to a groundless hole-riddled filter the next day and three days later nothing would be left.

I decided to figure out what had taken up residence in my bin.  A little Internet surfing revealed that our maggots were the larvae of black soldier flies (often referred to as BSFL) and a good thing.  Black soldier fly larvae are not pests. They quickly reduce the volume and weight of compost scraps, and prevent flies from laying eggs in the bin. I even found a story on NPR from a couple of weeks ago about a company that's using BSF larvae to commercially process food factory waste.

Black soldier fly larvae can live for several weeks, but our compost bin party will be coming to an end soon.  They'll slow down as the weather gets colder, and probably won't make it through the winter.  If that happens next year I'll have to figure out a way to re-introduce them to the bin.  I like having them there!

Five years ago today: New Thing #269--Make Your Own


  1. well, that is very cool! Isn't the internet great? What did we ever do without it? ha.

  2. It's so wonderful that you have a compost pile. I wish we had room for one.

    1. You can find really small compost bins (think the size of a trash can on wheels). If you had something, with the year-round nice weather I bet things would break down quickly.