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 Colony Collapse... or just lazy? 
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Joined: Thu Jun 11, 2015 9:41 am
Posts: 62
Location: Riverside, MO
Post Colony Collapse... or just lazy?
I was pretty sure I had my bin off to a roaring start. My larvae were getting bigger and bigger and eating ravenously. Then, suddenly, they are crowded into the bottom of the bin and appear either dead or extremely torpid. I pulled out the remains of their last feeding (some moldy hunks of bread) and most of the indigestible plant material that had accumulated over a few weeks. At the time when I found them like this, we were in the middle of a period of wet and unseasonably cool weather... so I figured maybe they just got chilly.

Well, now the weather is warming back up and they are still lifeless (perhaps literally). I put in some raw potato slices and a few other vegetable scraps, hoping they would come alive again, but so far it just seems to be drifting downhill. At the same time, I sorted out about a half-cup of the darkened ones and put them into the coir of my newly-built captive breeding enclosure. The glimmer of hope here is that at least a 3rd of the pre-pupae here were still wriggling pretty good when I transferred them, and when I went back to check on them, the mass "grave" had entirely dispersed. I'm hoping I have at least a handful of viable pupae that will eclose in the coming weeks.

So... what happened? I've done some more reading here recently about "colony collapse", and I suppose there might have been a day or 2 before the cool weather came in that I had a large number of larvae reaching the 5th instar coinciding with higher (low 90's) ambient temperatures. My bin is translucent plastic, filled with moist, airy coir, and kept in the shade... I didn't feel it was necessary to monitor temperature, but perhaps I was wrong.

What do you guys think? Can this colony collapse phenomenon occur without a heat spike? Maybe it really was hotter than I thought possible?

Also, if my video ever uploads (sorry it's longish and pretty boring with no narration), what are those shiny little critters scampering around in my substrate? There's not a large number of them but I wonder if they are any kind of threat. They appear to have wings and a long, shiny bronze, and very flexible abdomen.

Video at 53% .. I'll be back with it later.


Sun Jul 12, 2015 2:59 pm
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Joined: Thu Jun 11, 2015 9:41 am
Posts: 62
Location: Riverside, MO
Post Re: Colony Collapse... or just lazy?
Here's the un-narrated video tour of my setup. You can see (or not, the darker ones are harder to see, but they're in there) that there's still a lot of mature-looking larvae mixed in with the substrate. These were all crowded at the bottom prior to me getting in there and stirring things up. I'm hoping that at least some of these are (near) motionless because they've successfully pupated and at some point I'll have some adult flies appearing in my bin.

I'm not sure I want to wait that long, however - I think I may overhaul the entire thing and just put all of the existing larvae into the breeding enclosure. If they are still viable, they should do just as well (or perhaps better) in clean, fresh bedding. Then I'll buy some more mail-order maggots and start another cycle with closer monitoring and more careful feeding.



Video should be 90 deg CCW whenever YouTube gets around to processing my edit.


Sun Jul 12, 2015 3:58 pm
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Joined: Thu Jun 11, 2015 9:41 am
Posts: 62
Location: Riverside, MO
Post Re: Colony Collapse... or just lazy?
False alarm - for the most part, I guess.

I got into the bin again and really dug around. I went ahead and picked out everything I could find, live or "dead". To my relief, it seemed that between the substrate really starting to warm up and me adding a little moisture, the larvae were coming out of torpor. If the dead ones truly are dead, then it's no small die-off. When I dug really deep, however, I found quite a lot of really lively larvae nestled amongst the charcoal at the bottom of the bin.

I transferred everything I picked to the captive breeding enclosure, and then flooded the composter. Within minutes, the surface was erupting with large, healthy, dark-colored larvae. Only a couple cream-colored ones surfaced - but I would say 90% of what I found while digging around were dark. Immediately, they started scaling the sides of the bin, so I had to hurry up and install the velcro hook tape. Worked like a charm, just like everyone says. They don't seem to be attracted to the ramps very well - I only witnessed one volunteer to make the climb, and the ones I placed on the ramp eventually turned around and went back into the soup.

Assuming I have some fully-pupated larvae still in the bin, will the flooding kill them? I'm hoping the still-mobile ones will get up the ramp in the next 24-48 hours and then drain out the tea, but the substrate will still be very moist for a week or more, I'd guess. I know they prefer dryer stuff in which to metamorphose - but how bad is wetness for them at that stage?

P.S. ... The critters I mentioned in the earlier post appear to be a small subspecies of or cousin to the earwig. They're a little less than 1/2" long, reddish-brown, and have a small set of pincers at the end of a highly dextrous abdomen. The have folding hindwings and are capable of short, clumsy bursts of flight. I saw a few of their larvae in the substrate (I guessed, by size and shape), and the adults did not seem inclined to abandon the bin even when I was literally turning their world upside-down. I highly doubt that they present any threat, and in fact they may actually be eating the mites and other small free-loaders (I saw a very small few for the first time tonight)... so good on them. If you've any evidence to the contrary, please let me know.


Sun Jul 12, 2015 11:45 pm
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Post Re: Colony Collapse... or just lazy?
Thanks for the updates. Regarding pupation, an overly moist (or dry) habitat is probably not the best but there have been reports of BSFL pupating in flood & drain hydroponic systems.

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Mon Jul 13, 2015 7:27 pm
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Joined: Thu Jun 11, 2015 9:41 am
Posts: 62
Location: Riverside, MO
Post Re: Colony Collapse... or just lazy?
Checked the bin again this afternoon and on cursory inspection there were almost no larvae to be seen, except 2 dead/pupated 5th instar (guessing by color) lying motionless on the surface.

I opened up the collection can and tossed them in, just in case. I was worried that maybe my larvae eruption had given up and gone back under, but evidently they got "wise" to the ramps and when I gave the can a little toss I had maybe hundreds of wriggling pre-pupae in there. Success! I went ahead and drained out the tea. I got a good gush at first and it is still dripping, hours later.

NOW.... I appear to be on track to have a massive explosion of eclosing adults at some point in the future. I'm wondering if there's a way to meter these out over time.

When is the best time, if any, to artificially push the pause button on the life cycle? Could I maybe refrigerate some pre-pupae and then put a few dozen into the breeding enclosure at a time? Or is it better to wait until they are full-on pupated? Or should I just live with the boom-bust scenario until things sort of even out over time?

Ideally I'd like to have actively feeding larvae in my composter at all times. Right now I have zero (or close to it).

Sorry this has morphed into something other than a trouble-shooting thread. Feel free to move it elsewhere :)


Mon Jul 13, 2015 10:01 pm
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Post Re: Colony Collapse... or just lazy?
jf371 wrote:
... Or should I just live with the boom-bust scenario until things sort of even out over time?
That would certainly be the easiest. The larvae naturally develope at different rates and I found that while the number of larvae and flies fluctuates it never drops to zero so the generations overlap without distinct boundaries.

Quote:
Sorry this has morphed into something other than a trouble-shooting thread. Feel free to move it elsewhere :)
Moved to the Cultivation section

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I Believe The Black Soldier Fly Has The Potential To Be A Beneficial Insect Second Only To Pollinating Bees


Mon Jul 13, 2015 10:13 pm
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Joined: Thu Jun 11, 2015 9:41 am
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Location: Riverside, MO
Post Re: Colony Collapse... or just lazy?
I've got flies! :o Now for some eggs...


Attachments:
File comment: Here is a shot of my breeding enclosure. Pretty proud of it (my mom helped!), but the proof will be when I complete the cycle and have abundant larvae eating all my kitchen waste.
HoneymoonSuite.jpg
HoneymoonSuite.jpg [ 214.59 KiB | Viewed 5870 times ]
File comment: The flyoneers!
First_Flies.jpg
First_Flies.jpg [ 202.9 KiB | Viewed 5870 times ]
Sat Jul 18, 2015 9:09 pm
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Joined: Thu Jun 11, 2015 9:41 am
Posts: 62
Location: Riverside, MO
Post Re: Colony Collapse... or just lazy?
I did get several egg clusters in my waffle-kerfed wood block. This morning it looked the first one had broken apart, so I dug around in the food scraps below - there were lots of little larvae. So, my cycle is complete - I've come back around to where I started.

My adult flies are starting to die off - at its peak I would say my enclosure had somewhere between 100 and 200 adults. Now it's probably less than 100. New ones still coming out, though - I just caught 6 or 7 more in the compost bin and moved them over. One was just emerging from the substrate, wings still wrinkly. It's almost funny how easy the adults are to catch, even with flight-capable wings. Even when they take flight they tend to circle around and land inside the bin again. That said, there have been a few that buzzed straight off. Godspeed, little black soldiers.

I'm hoping that there's been some egg-laying going on down in the bait bowl of the breeding enclosure, because I would guess that there's only about 5 egg clusters on the egg trap. I have observed several mating pairs over the last couple weeks, but less than I'd hoped given how many adults there were. They seem to stay coupled for quite a while, so I'd expect to catch them in the act more often.

I'm also thinking that my egg clusters look fairly small, possibly owing to the fact that a lot of my flies appeared to be undersized (maybe even sterile?). I'm guessing that because of stresses on the compost bin I had quite a lot of of relatively small larvae stop feeding and go ahead into the pupae stage.

Even if my concerns turn out to be true - I think I've got a pretty firm foothold here. Soon (perhaps today), I'll go ahead and move some of the larvae-laden bait bucket contents into the composting bin and get that started again. I don't have anything to feed ripe larvae to yet - so I'll just continue to feed my closed cycle for now. I'll keep learning from my mistakes and hopefully avoid catastrophe.


Wed Jul 29, 2015 4:21 pm
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