BSFL bin - 2 week update

[Andrew]

It's only been 2 weeks, but so far neither excessive moisture or smell has been a problem. Since I regularly add coffee grounds, the predominant smell is coffee-ish. It doesn't smell like worm compost, but there's nothing close to offensive about the smell...so far. :-)

I'm on the 3rd version of my DIY BSFL bin. I've modified it to a bin-within-a-bin design. The smaller bin houses the feeding area. This 5 gal. bin always has condensation on the walls. The mature grubs easily crawl up the vertical walls, under the loosely closed lid & over the edge into the larger bin. This larger, outer bin doubles as the catch tray for mature grubs leaving the small bin and the place for them to pupate and eventually emerge as black soldier flies.

Here are the 2 bins without lids. I use bubble insulation to cover the feeding surface. For now this easily keeps the temps in the 80-100F range. When temps are lower I will tape bubble wrap on the outer bottom & sides of the smaller bin.

I've removed the ramp in the smaller bin. This allows for both greater surface area and volume for the active grubs. I started with 2 cups of grubs, eggs, 1/2 cup sawdust and ~6 cups coir. I'll round up and say 9 cups or just over 1/2 gal. This 5 gal. bin is now 1/2 full = 2.5 gal. I feed ~2 cups of food waste each day. The dampest coir/residue mix is still fairly loose.

The large bin has 1.25" of loose coir for the mature grubs to 'hibernate' until Spring. The 2 wood blocks serve as a base for the smaller bin to sit on. The small glass jar in one corner contains a bit of fruit in case any juvenile grubs escape and need food. The toilet paper rolls serve as hiding places for the mature grubs who prefer that.

I'll end with a short clip of "grubbsies dancing" in coffee grounds. Note to DSF: these are 2 week old larvae and hopefully won't give you a fright like the mature prepupa did. Still, you might want to prepare yourself if you choose to view the vid. If you listen carefully, you can hear the rainfall-like sound they make while dancing.

[D S Foxx]

THANK YOU! I love it when people tell me what bits to skip, and this definitely qualifies. The younger they are, the more objectionable I find the sight. Useful, yes; fun to watch, no. And as for listening, I think that's nearly as bad; when I put the bin in the rather echoing laundry room last winter, the sound from inside the bucket-set reminded me of old horror films. Specifically the scenes where people are buried alive and hear things digging through the dirt toward them...

On a more positive note, that's quite a luxury grub habitat you've got going there. Grub playscape?

DSF
still a reluctant grub wrangler

[Andrew]

LOL. I guess I'm in the minority even in the BSF sub-group. I find the dancing grubs amusing and the churning sound soothing. Just as well I'm not a fan of horror films.

Fortunately grub "luxury" is cheap. The 18 gal. orange bin was on sale at Target last Halloween. Same type of bin we use for worms. The playscape are toilet paper rolls & a glass jam jar in coir. They'd probably just be as happy with leaves & dirt.

[Jason]

Nice work. If memory serves you're the first person here to really document a BSFL bin in detail. It's interesting and will surely be helpful to people.

Keep us updated on the progress!

[Andrew]

Thanks, Jason. Here's a 'negative' update. Although new food disappears from the surface each day, it seems some of the denser chunks sink into the coir where the grubs continue to work on it. Some chunks of cheese from lasagna I added a few days ago sank to the bottom where the coir is wettest. When I decided to check on what was down in the bottom, a very strong cheesy smell hit me. That might be ok for those who prefer strong smelling cheeses, but it was unpleasant for me. I'll avoid adding such things into the bin for now. Later when I have more grubs I'll probably break up cheese & meat into smaller pieces. Fortunately, once the chunks were back at the bottom, the smell was gone and the bin went back to it's usual coffee-ish smell.

[Josh Gelatt]

Where does one buy BSFL to get started?

Also, since I live in the North and it is beginning to get colder, is this possible to do indoors (especially regarding the issue of new eggs being laid that will not involve hundreds of soldier flies buzzing indoors)?

[Andrew]

I bought a "starter kit" from Jerry at:
http://blacksoldierflyblog.com/the_biopod/bsf-multi-stage-starter-kit/

It was $29 shipped and included ~1k juvenile grubs + eggs that have hatched into another 1.5-2.5k grubs. 300-400 grubs matured and are now pupating, waiting for Spring to emerge as flies. BSF have stopped laying even in the south, so the starter kit won't be available again until next year. He might be able to send you 2-3k grubs if you want to start with a small colony. That's basically what I've ended up with now. My 2-3k grubs are processing about 2 cups of food waste each day. Some of them are still small, so the amount they eat may go up a bit more before they hit a plateau. It just won't be a huge amount - maybe 3 cups or ~1/3 lb./day?

The only other sources of grubs I found are considerably more expensive. They're marketed as Phoenix Worms sold to owners of pet lizards, frogs, etc.:
http://www.phoenixworm.com/servlet/the-Phoenix-Worms/searchpath/916...
http://www.wormman.com/pd_phoenix.cfm

The main advantage in having this small colony active through the winter is that the grubs will be producing residue/compost. By Spring the bin should be able to attract BSF females when they emerge to lay eggs. The scent of even a small active colony is supposed to attract them. It sounds like Jerry starts shipping the starter kits again in late April/early May, so you get maybe a month head start by maintaining a winter bin. Of course you also dispose of ~2 lbs/week food waste that the worms can't handle.

My bin has been in an unheated shed. I think it would be ok in a basement, garage or other unheated area. They produce their own heat. It sounds like air temps could be freezing and they'll still keep their bin warm as long as they have food. I put my bin outside twice with night temps in the mid 50s. Bin temp in the morning was still in the 80s.

From what I've read, the flies don't like to go indoors. They live 5-8 days and are mostly looking to mate & lay eggs, so there's nothing inside that interests them. I doubt there's any danger of flies now and through the winter in MI. I haven't seen any in No. CA recently. You would put the bin outdoors in late Spring so BSF could come and lay eggs.

[Kevin R]

Andrew, I like the photos showing the architecture of your bin. My simple bucket is back to being super active with the "soothing" sound of BSFL churning. I am truly amazed with the ability of the mature BSFL. They are often moving on my balcony floor, which means they scaled the vertical walls of the bin and found a crack or whole in the lid. I think this speaks to the angle of the ramp that is needed. Really, it appear you can make it as steep as you want. This might help mitigating the number of non mature BSFL get into your mature area.

[D S Foxx]

Re: BSF indoors--I've read that, too, but the first time I saw a soldier fly, to know it, was indoors. As I recall, I ran around like an idiot crying for someone come kill the thing. New to TX back then, what can I say? It looked like a wasp to me!

Newly hatched BSF seem to seek bright light (for wing drying?). In my current apartment, even before starting a grubbery I'd get the occasional confused wasp-mimic buzzing through the place to the picture window, though only on sunny days; nothing to worry about, now that I know what they are, but it can be rather startling. A friend with one of those "compost buckets" that only serves to hold waste for short periods had a rather less innocuous encounter, thus proving her neighborhood has them, too. And let's not forget the other source of indoor flies: grubs can, and do, come indoors if given the opportunity, and in a heated home, some few may mature to the winged stage.

I really wish I hadn't just thought that. Eww. ...Excuse me, I think I have to sweep or mop or something.

DSF
last adult sighting: yesterday. Didn't look today.

[D S Foxx]

Re: sources

Phoenix worms and calcigrubs may be mature instars, more stable for use as bird or reptile food but not as desirable for starting a bin as mixed-stage larvae. Jerry's the only one I've seen selling grubs in scented food/bedding, which is probably best (should serve to attract any natives as well as encourage the first adults to return). But if you know someone with a bin, you could just hit them up in spring, ask them for a starter set. Shipping can be done by post, same as with worms, just label it Live Bait.

DSF


DSF

[Andrew]

Kevin, good to hear your grubs are 'alive' again. Unless you're still getting some hot days, it might be a good idea to stick some insulation on top to keep them from going dormant on the next frost. Did you move the ones in your worm bin over to the BSFL bin?

Yeah, those grubs can really wedge themselves into the smallest crack or crevice. As long as there's enough condensation they can climb vertical walls and the smaller ones can even hang out on the "ceiling". That's why I removed the ramp on this small bin. I haven't decided whether I'll put the ramp back into the larger setup next year. There may not be enough condensation when the vent/entrance holes are drilled in the Spring.