restarting the colony 2009

Starting my third year with the black soldier fly

I’m going into this season with a small colony made up of grubs that were laid last fall. Where I live the winters are mild so it was fairly easy to maintain the colony through the cool months. At the end of last summer my BioPod was full of compost and I should have harvested it. As a result of that neglect my beautiful compost became anaerobic, dense and a bit smelly. What can I say? It’s been a hectic year. :) I think early fall may be a good time for removing the BSF compost because the grubs are likely to be less active on average in winter versus the warm months. I believe the churning action of a very active colony (summer) is an important factor in keeping the compost aerated and “fresh”. I said early fall for compost harvesting because I’m afraid that if you wait too long in the season you won’t have time to rebuild the colony to near maximum size in preparation for the winter when BSF breeding stops (unless you’re in the tropics).

Spring cleaning

first BSF of 2009

BSF don’t normally land on people,
but this one had just emerged from it’s pupa so I was able to handle it.

I removed all of the compost and washed my BioPod. I hand picked a few hundred of the light colored juvenile grubs from the old compost and added them to the unit along with some fresh food scraps. I didn’t clean the grubs themselves so a small amount of the old compost was transferred along with them. This old material will act as a great attractant to BSF adults who have now started the mating season. A healthy and balanced BSF colony doesn’t have a strong or bad odor, but the females will always be attracted to the faint scent of an established colony. As I mentioned previously, my compost is anaerobic now and therefore smelly, but the typical mild smelling compost from a balanced culture would work just as well.

BioPod-spring cleaning

A new drain

As you can see from the first photo in this post I have replaced the BioPod’s liquid collection jar with a straight drain into the ground. (I hope you won’t be too disappointed with me Dr. Olivier.) I haven’t been gardening and to date I haven’t done anything productive with the liquid (also called “tea”). For that reason I’m opting for the convenience of the straight drain for now. To see how I set up the drain you can go to my “Tips and Tweaks” page.

The pond

You can also see my pond in the photo. I moved the BioPod near the pond because I’ll be feeding fish scraps and culls to my BSF colony this year. I don’t enjoy killing fish, but to maintain the population in a healthy balance I will be removing some of them. I’ll have some help from birds, turtles, and snakes, but the pond is fairly close to the house and wild predators are limited. With the BioPod I’ll be able to convert the excess fish into nutritious black soldier fly grubs and return them to the pond as fish feed. I have a post about my philosophy regarding feeding BSF grubs to other animals here.

Black soldier fly grubs are also fantastic fish bait, so having the BioPod near the pond will be very convenient for fishing. I’ve created a page about BSF as bait which you can find here.

Winter BSF culturing

As I mentioned earlier I did keep the colony going through the winter, but I didn’t keep any records. The one thing I can confirm is that the BSF grubs will interrupt their usual development during the cold season. I had very few BSF laying eggs by October and the last one I observed laid her eggs late in that month. By November I stopped seeing any smaller grubs in my colony. I assume then, that the grubs that currently make up my colony are at least five months old. During the summer this stage would only last 2-3 weeks. Next winter I want to be better prepared to test cold weather bio-composting and I hope that some of you will participate in it with me. At the end of this summer we should start a thread about this at the BioPod forum to share strategies and results.

Logging this year’s results

My goal this year is to keep a log of all the food I add to the colony and the weight of the grubs produced. I’ll be fairly general about recording the composition of the food scraps so this won’t be a controlled experiment. The fact that I’ll be adding a large amount of whole fish and fish scraps will certainly effect my results. My goal is to provide a general outline of what you might expect. You can find the log in the column on the right of this page under Black Soldier Fly Pages, or simply click here.

Update: Since we now have a discussion forum we will be disabling comments here on the blog. Anyone can read the forum, but to join in on the conversation you will need to register. This is an easy and painless process, and it’s necessary to keep spammers from, well, spamming up the place. :)

The forum can be accessed here (forum) and you will see a link for registration in the upper left corner of the forum. The legal language on the registration form is very basic and is what came with the forum software. In short, we won’t share your information, and please don’t be vulgar or break the law. 😉


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9 thoughts on “refreshing the colony

  • May 5, 2009 at 12:43 pm

    It’s good to see you starting up again. The log of materials in will be interesting to compare with the amount of compost produced at the end of the season.

  • May 20, 2009 at 8:08 am

    Thanks Mike,
    It feels great to get back working with my favorite bug. :)

  • June 15, 2009 at 9:46 pm

    Hey Jerry, what state / USDA zone are you in? Did you overwinter your Biopod outside?

    Is that the 4′ commercial unit you have there? Are you selling those yet?

    Interesting that the BSFL can essentially go into “suspend” mode over the winter. I wonder if you can do that intentionally by keeping them in the refrigerator? I once bought regular fly larvae as fish food and kept them alive in the fridge for approx 2 months.

  • June 17, 2009 at 6:01 pm

    Jase, good to hear from you again!

    I’m in zone 8b, in Georgia just a few miles from Florida. I did overwinter my colony this year, but poorly. I didn’t process much waste and mostly the colony was dormant. By this spring I still had several hundred 5 month old grubs surviving from last fall. In warm weather the same grubs would have developed fully in 2-3 weeks.

    You can certainly suspend the development of the grubs with refrigeration. I think 50-60ºF is about right, but I haven’t tried it myself. Something to consider when refrigerating them is that they still need air and they must not dehydrate.

    The commercial ProtaPods are available but shipping is really expensive due to the size.

  • June 22, 2009 at 1:23 pm

    My new Bio-Pod seems to be functioning, there are a zillion little grubs in there munching away on the food scraps. I was planning, however, to use it also for dog and cat poop, and was disappointed to see in the Bio-Pod Guide that the home unit was not suitable for this because of dangers of disease, etc. We have always composted our dog poop (but not the cat) with no problems. So I’m wondering how hard it would be to build some sort of container that I could use to digest the dog and cat poop (we use wheat litter for the cats) separately and just dump in some of the grubs from the Bio-Pod to get it going. Are there any plans anywhere for homemade units? I guess I would just use the mature grubs from that one to feed to wild birds, not our chickens. The point is mostly to get rid of the cat litter and doggie doo without sending it to the landfill. I could let it drain onto the ground, I guess under the trees away from our garden. Maybe I could make it so it just let the mature grubs crawl out onto the ground for the birds too. It’s a bummer not to be able to feed them to the chickens tho, that was my main reason for buying the Bio-pod.

  • June 25, 2009 at 6:06 am

    Hi Harmon,

    The reason the BioPod manufacturer says not to process fecal matter of any kind is because of liability issues. Anytime you handle poop there is a risk of infection. Processing pet waste with BSF is probably similar to cleaning a toilet, you keep your fingers out of your mouth while doing it and you sanitize yourself afterward.

    You certainly could add pet waste to the colony and they would process it easily. As with any type of waste you would want to make sure you didn’t overload the colony with a large amount at one time. Of course if you added any type of manure you would have to expect a certain amount of odor which isn’t usually an issue when you process kitchen scraps.

    BSF that have been raised on animal waste have been tested as animal feed in several studies. Often in these studies the grubs were sanitized by cooking or drying before being fed to animals, but not always. I’ve read that if you raise BSF grubs with manure, that you should not feed those grubs back to the same genus of animals. For example, if you raise the grubs on mammal waste you could feed them to birds, reptiles, and fish. If you raise them on chicken manure you could feed them to mammals, reptiles, fish, and so on. My knowledge about this is limited, so you should do some research before taking any action.

    Thanks for your business Harmon, I’m glad to hear that your BSF eggs hatched and are thriving. Let me know if you have any more questions.

  • September 24, 2009 at 4:30 pm

    Hey Jerry! Check out this post here:

    My chickens didn’t want the food so I’m offering it to the BSF Gods! My most recent post on that thread discusses what I did with the lid that has 3 clutches of eggs. You mention it takes 4 days or so for them to hatch? My question: What do the egg clutches look like AFTER the larvae have hatched?


    • September 24, 2009 at 5:00 pm

      Hey there BYC!

      The egg cluster is light brown after the larvae hatch and the texture looks “fuzzy”. A picture is worth…..

      (click image to enlarge)

      … a thousand eggs. :)

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