Generosity and Larvae

I'm constantly amazed and humbled by the generosity of the people in this community. A chance remark to an acquaintance brought an introduction to a local who has recently started breeding Black Soldier Flies for their larvae. BSF larvae are used to compost kitchen scraps and other waste, and their leavings can be used as a simple soil amendment in the garden. Better yet, their leavings can be fed to worms, who in turn create double-plus good castings for the garden (as well as bait for the person who fishes in your family). And last, but not least: the larvae makes for fantastic chicken feed!

John invited me to his property, and showed me his setup of a half-dozen breeding boxes. Met his lovely partner Liz, and had a great time just chatting about life in general. I didn't offer to buy a batch of grubs at the time, mentioning it would be a few weeks before I could set up a proper brooder. Fast forward a few weeks, to an email from John:

"I've had some pretty heavy crawl-off since [we last chatted] and I'd be happy to drop off a bag at the feed store if you'd like..."

Oh heck yeah, the hens would LOVE some grubs! I arrive at work, and not only does John have a can of mature grubs for our girls, but a box for breeding, a chicken-wire box top, nesting medium, and a tub of young grubs to grow! He gave me a quick rundown on how to attract local, mature BSF's for more grub breeding, and was on his way. [Spouse, we have GOT to feed these folks some of your amazing pasta as a "thank you"... ]

Got the grubs home, and quickly threw together a temporary setup for the young larvae. A hole was cut near the box bottom, and a piece of hardware cloth guard affixed over the hole via duct-tape. (I'll take off the tape and use proper bolts and washers to secure the hardware cloth this week.) The sawhorses and box platform have been placed underneath a grove of shady oaks, so it will keep the grubs at a comfortable temperature. The platform is on a slight downward slope, and the box opening facing the downwards slope, which will encourage mature grubs will crawl out through the hardware cloth-covered opening and any excess moisture drain out easily. The bucket below will catch the grubs as they leave, who will then become high-protein, live chicken feed.

I've set out a batch of corn to ferment in order to attract mature BSF's to breed. The corn, as well as the scent of the grubs, should bring enough flies for a healthy breeding colony. Cardboard pieces have been set inside the box as temporary breeding cubbies for the flies to lay their eggs. To feed the young pupae in the box now, I've thrown in a batch of wilting lettuce and some goose poo generously donated by Miss Cecily. Tomorrow morning, they'll start getting regular meals of feed that has been knocked to the ground by the chickens and geese - feed which formerly was dumped into the big compost pile.

I've also placed a pet fence around the whole setup - John mentioned that the grubs can sometimes attract raccoons and other grub-loving creatures.

Next things needed: create a covered shelter for the brooder - don't want rain to drown the grubs - and a more secure structure to hold the breeding box. Oh, and make permanent breeding cubbies by drilling small holes in a couple pieces of wood, and attaching to the sides of the brooder box.

I feel like such a geek to be so excited over breeding larvae!

Side note: "Maggots are not Black Soldier Fly Larvae", in case you wanted to know the difference.

[Pic top: mature grubs, ready to either become flies, or get eaten by our girls. They feel dry and leathery. Second pic: details of the temporary setup. Pic bottom: the current setup.]


  1. very cool. Tho, I bet an enterprising raccoon could tear your current setup apart in about 30 seconds.

  2. people are very kind and thoughtful in my experience....mind u it helps if u are a sweet person to!!!

  3. Hi d.a.,

    Thanks for linking to my black soldier fly blog. I'm glad John encouraged you to try your hand at raising BSF. I just want to set one thing straight; BSF larvae are indeed maggots. There are over 100,000 species of flies and to my knowledge the larvae of all of them are commonly called maggots. It's a shame that the word has such a negative connotation and I'm sure it is slowing the growth of this fantastic bio-conversion technique. BSF are harmless creatures that have great potential to serve humans and I believe that many more people will gradually learn to appreciate them.

    I've never been a big fan of house flies or other pest fly species, but to be fair we shouldn't react so harshly to them or their larval stage either. Human activity has surely increased the number of disease carrying pest flies, and we should work to limit them, but those flies also play an important role in nature. In general we need to learn to harmonize with nature, not treat it as an adversary.

    Thanks for helping to spread the word!


Of Mice and Various Snakes and new Duck Feed Station

As mentioned in the previous post, our region is experiencing a near-Biblical plague of mice. "It's due to all the moisture we had...