Saturday, June 10, 2017

Super Composters

Adult Black Soldier Fly
Previous to this year, I had barely heard about Black Soldier flies. I had already purchased some from The Reptile Specialist in Tucson several years ago as reptile feed, but had a difficult time keeping them alive. Unfortunately, I did not know, at the time, how to properly care for these beasts. Fast forward to this winter when I’m out checking on the table scraps in my compost and notice the compost moving along with a noise of critters moving around. So, I take a nearby short hoe and turn them over only to find – black soldier fly larvae by the hundreds.


My food scraps bucket before black soldier flies.


With an especially wet winter, it became quite difficult to keep my black soldier fly larvae in the wooden barrel that is my table scraps compost bin. They would crawl out and leave me having to scoop out their bodies and throw them into the garden. From time to time they became a little bit of a nuisance, but then I just forgot about them. That is until a couple weeks ago when I went outside to throw the inside food scrap bucket into the barrel. I was expecting to see the compost pile at least 8 inches higher and wondered what had happened. I noticed that the regular fruit fly colony that hovered above the bin had completely disappeared and, as I put my hand above the compost area I could feel, on an already warm day, a noticeable heat emanating from the pile. I pulled the first layer of the pile up only to discover thousands of black soldier flies writhing around in mass along the surface.


A Black Soldier Fly resting on a zucchini leaf


Though this may sound disgusting, I have found Black Soldier fly larvae to be the piranhas of the larvae world. It is not that they eat other larvae (such as fruit fly larvae) but rather it is that they out-compete every other fly in relation to all the food scraps that humans produce as well as a host of other things that I will not mention in this blog post. But I will say how cool it is to throw old slices of pizza, fat, bones and other scraps (that you wouldn’t do in a conventional compost situation) into a bin in which they are (within hours) recycled into high quality compost. There is a very good illustration of this in a youtube video with black soldier flies and a hamburger. It is amazing how much heat they produce when they are in mass. This heat does seem to be a factor in helping them to break down things such as whole pieces of rotten fruit or bones.


Black Soldier Flies laying eggs in the food scraps compost bin


So now, I am able to supply each of my nearby gardening friends who have both chickens and compost piles with a great supply of both composters and feed. Should you find any of these friends in a compost bin near you, be sure to welcome them in and enjoy the benefits that result.




Black Soldier Fly Larvae with resulting composted material



About 2-3 minutes of Black Soldier Fly activity - Enjoy!


2 comments:

  1. We've had black flies in our compost bins for several years and are very happy to see them. We do something from time to time that the black flies don't like, but as soon as the compost is to their liking they come back. We'll be making composting towers for the earth worms for our cellulose type of recyclables. Cellulose is where the earth worms out compete the black flies.

    ReplyDelete
    Replies
    1. Dear O.G. Yardens,

      You are completely right. Black Soldier flies definitely prefer high-energy foods.

      Delete

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