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BSF project in Colorado
http://blacksoldierflyblog.com/forum/viewtopic.php?f=17&t=178
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Author:  BorealWormer [ Thu Jan 12, 2012 2:55 pm ]
Post subject:  Re: BSF project in Colorado

Looks like you have lots of room in your breeder tote so I would add more different kinds of attractants. I limited my setup to used coffee grounds as they do not smell and my bin is in my residence. If odors are not a problem try a few of the more pungent attractants as suggested by Jerry (link) and PeteB (link).

Author:  biobehaviorist [ Wed Jan 18, 2012 2:22 pm ]
Post subject:  Re: BSF project in Colorado

we had 3 adults emerge over the weekend. One drowned in a dab of water sitting in the corner of the tote and the other two I believe are males, I witnessed them come together in the air and land with lots of wing beats and kicking and then they separated without going tail to tail like the mating couples do. moisture has stayed in the tote, the sponges are dry, but there is condensation on the lid of the tote and the coffee grounds are still wet after a week. I also saw one grub moving perhaps it is another adult ready to emerge or maybe it is just settling in to transform. I hope more adults emerge in time so that the ones already out have a chance to mate before its too late.

Would I really be more successful with other egg traps? At this point i know there are not enough flies for it to matter but there will be soon hopefully. My logic is telling me that If they are confined into a tote, they will lay eggs in whatever they can get, preference is not really important as long as the basic requirements are fulfilled correct?

Author:  BorealWormer [ Wed Jan 18, 2012 3:03 pm ]
Post subject:  Re: BSF project in Colorado

biobehaviorist wrote:
Would I really be more successful with other egg traps?
My attitude is that more can't hurt. Tarvus had a very specific recommendation about what flute size in the cardboard worked best but I can't remember and his site still down. I'd have a few of varying sizes. I should say that in my experimenting the flies never did deposit eggs in the cardboard and Heather Twist had a similar experience (link).

Quote:
My logic is telling me that If they are confined into a tote, they will lay eggs in whatever they can get, preference is not really important as long as the basic requirements are fulfilled correct?
That's true but the larvae are going to be looking for food immediately after they hatch. The attractants (used coffee grounds or other) serve to have the eggs laid where they can be easily found and are a food source close at hand.

Author:  biobehaviorist [ Wed Jan 25, 2012 2:05 pm ]
Post subject:  Re: BSF project in Colorado

the breeder has been set up for 2 weeks now. So far we have had about 5 adults emerge and no eggs laid. The most interesting thing thats happened so far is that some of the grubs are still moving. Today there were about 50 grubs that had moved from the sawdust, across the tote and underneath the sponges, even burrowing into them. Can anyone lend some insight to why this is occurring? It is my understanding that the grubs, after going into the final instar and becoming dark, seek a dry dark area to pupate and become inactive, hence the sawdust, but it is clear they have another preference... It has been two weeks and they are still wiggling and actively seeking moisture. Is this delaying them from emerging as adults? and Is there a way to speed up this process? I think there is something that triggers them into pupating and going into the "cocoon", still the final instar, but I believe there is some sort of transition that happens.

Author:  Tarvus [ Thu Jan 26, 2012 2:02 pm ]
Post subject:  Re: BSF project in Colorado

biobehaviorist wrote:
It has been two weeks and they are still wiggling and actively seeking moisture. Is this delaying them from emerging as adults? and Is there a way to speed up this process? I think there is something that triggers them into pupating and going into the "cocoon", still the final instar, but I believe there is some sort of transition that happens.


About the earliest you can expect an adult to emerge from the "pupation" stage is about 3 weeks. Some take several months. Once they start to emerge, you may see a few each subsequent day. Don't expect to see a "cocoon"-like pupa like you might with houseflies or other insects. The BSF pupa essentially looks the same as the brown grub that crawled out of your bin. They remain at least semi-mobile right up until emergence, but often appear immobile leading you to believe they are dead.

In my personal experience with captive breeding, it seemed I averaged one egg cluster per 40 or so captive adult flies, but that may vary with conditions.

As far a corrugated cardboard egg traps, use the "b-flute" size (like you find on beer or soda flats) rather than the larger and more common "C-flute" corrugated most packing boxes are made of. I glue 5 or 6 one inch wide strips together and fix them to the sides of my bin with the corrugations running vertically. Ninety percent of your egg clutches will be laid on the lower side. The BSF like to crawl under the strips and insert their ovipositors upwards into the flutes.

Author:  BorealWormer [ Thu Jan 26, 2012 2:22 pm ]
Post subject:  Re: BSF project in Colorado

Tarvus wrote:
As far a corrugated cardboard egg traps, use the "b-flute" size (like you find on beer or soda flats) rather than the larger and more common "C-flute" corrugated most packing boxes are made of. I glue 5 or 6 one inch wide strips together and fix them to the sides of my bin with the corrugations running vertically. Ninety percent of your egg clutches will be laid on the lower side. The BSF like to crawl under the strips and insert their ovipositors upwards into the flutes.
Thank you Brian. I knew that you had that info on your blog but couldn't remember the details.

Author:  BorealWormer [ Thu Jan 26, 2012 2:32 pm ]
Post subject:  Re: BSF project in Colorado

Tarvus wrote:
Don't expect to see a "cocoon"-like pupa like you might with houseflies or other insects. The BSF pupa essentially looks the same as the brown grub that crawled out of your bin.
I came across this while reading - "Some pupae remain inside the exoskeleton of the final larval instar and receive the name of puparium (plural, puparia); the flies of the families Stratiomyidae, Syrphidae and others have puparia"(link). The black soldier fly, Hermetia illucens, is a fly of the family Stratiomyidae.

Also from the same link "Emergence - Insects emerge (eclose) from pupae by splitting the pupal case"

Author:  biobehaviorist [ Thu Jan 26, 2012 11:19 pm ]
Post subject:  Re: BSF project in Colorado

Thanks for the responses guys, I have just one questions about their attraction to the sponges. I thought they would seek dry shelter once they were in the last instar, but that clearly is not the case. I have one theory tho, that the sawdust might not provide them with the "sheltered" feeling. Cockroaches are known to be postively "thigmotactic" which means they seek cracks or crevices that are small enough for them to feel their surroundings pressing against their bodies. Perhaps final instar BSFL are the same way? they might not care about the damp sponges, they just want to burrow and feel safe from being crushed or discovered?

Author:  BorealWormer [ Thu Feb 02, 2012 6:05 pm ]
Post subject:  Re: BSF project in Colorado

Tarvus wrote:
As far a corrugated cardboard egg traps, use the "b-flute" size (like you find on beer or soda flats) rather than the larger and more common "C-flute" corrugated most packing boxes are made of. I glue 5 or 6 one inch wide strips together and fix them to the sides of my bin with the corrugations running vertically. Ninety percent of your egg clutches will be laid on the lower side. The BSF like to crawl under the strips and insert their ovipositors upwards into the flutes.
This is confirmed in Rearing Methods for the Black Soldier Fly (Diptera: Stratiomyidae) by D. CRAIG SHEPPARD et al

"There are several sizes of corrugated card-board and experience indicated that the smaller open-ings were preferred. We used cardboard with three flutes per centimeter."

Author:  Tarvus [ Thu Feb 02, 2012 6:23 pm ]
Post subject:  Re: BSF project in Colorado

biobehaviorist wrote:
Thanks for the responses guys, I have just one questions about their attraction to the sponges. I thought they would seek dry shelter once they were in the last instar, but that clearly is not the case. I have one theory tho, that the sawdust might not provide them with the "sheltered" feeling. Cockroaches are known to be postively "thigmotactic" which means they seek cracks or crevices that are small enough for them to feel their surroundings pressing against their bodies. Perhaps final instar BSFL are the same way? they might not care about the damp sponges, they just want to burrow and feel safe from being crushed or discovered?


That may be the case, but I suspect it's more a case of them seeking a bit of moisture or a humid environment. Excessive humidity and rain (even if they are not being directly wetted by the rain), will prompt mass migration. I learned this when some 18,000 final instar larvae decided to migrate out of a 5 gallon bucket I had placed on my patio near the pool one night. I skimmed dozens of larvae out of the pool every day for the next several months and had a massive hatch out of mature BSF that populated the pool cage for about the same period of time. This did not sit well with the spousal unit. If you value your marriage, let me warn you this can lead to severe marital discord! :shock:

Author:  biobehaviorist [ Wed Feb 15, 2012 3:05 pm ]
Post subject:  Re: BSF project in Colorado

Well its been a few more weeks and I think the adults are starting to come out. we have about 15 healthy adults buzzing around the breeder, and two have been observed in the mating position, back to back. I have 2 egg traps set up now, one with coffee grounds and moldy fish pellets, the other with coffee grounds and some soggy bagel pieces. Hope to see some eggs by next week, just have to wait and see... any other advice to encourage breeding/ovipositing? right now it is critical that we get some eggs to get the next generation going as all of my grubs have now gone into the breeding tote. If no eggs are laid, we will be forced to abandon the project or order some more grubs :oops:

Author:  BorealWormer [ Wed Feb 15, 2012 3:19 pm ]
Post subject:  Re: BSF project in Colorado

biobehaviorist wrote:
.. any other advice to encourage breeding/ovipositing?
Soft lighting and mood music ;) :D

Thanks for the update. In my experiments no eggs have ever been laid in the flutes of the cardboard but I think I've figured out why. In the research published from the SE USA it was noted that BSF do not deposit their eggs in wet material and their attractants were purposely kept wet to promote ovipositing in the flutes of the cardboard. I don't know if it's important to you that the eggs are in the cardboard rather than the attractant.

The UCG I've been using is dry enough that the BSF were ovipositing in it. As a test I've outfitted two of the UCG containers with cardboard on the underside of their lids and added enough water to the UCG to make it soupy.

Author:  Tarvus [ Wed Feb 15, 2012 3:36 pm ]
Post subject:  Re: BSF project in Colorado

BorealWormer wrote:
biobehaviorist wrote:
.. any other advice to encourage breeding/ovipositing?
Soft lighting and mood music ;) :D

Thanks for the update. In my experiments no eggs have ever been laid in the flutes of the cardboard but I think I've figured out why. In the research published from the SE USA it was noted that BSF do not deposit their eggs in wet material and their attractants were purposely kept wet to promote ovipositing in the flutes of the cardboard. I don't know if it's important to you that the eggs are in the cardboard rather than the attractant.

The UCG I've been using is dry enough that the BSF were ovipositing in it. As a test I've outfitted two of the UCG containers with cardboard on the underside of their lids and added enough water to the UCG to make it soupy.


This is correct. They won't deposit eggs in wet material. Once the eggs ARE deposited, they won't hatch out if the material becomes wet. Two techniques I've used to hatch out eggs include putting the sections of the egg bearing cardboard in a ziplock back along with a piece of fresh bread and keeping it in a warm, dark place. (The bread provides enough humidity without being soggy, and also provides a food source for the microscopic hatchlings to migrate into.) The second technique involves layering an inch or so of very moist food in the bottom of a rubbermaid tote and suspending the egg bearing cardboard strips on a "table" made from 1/4" hardware cloth (bend the ends of the sheet of hardware cloth down a couple if inches at right angles to make legs so the strips are suspended an inch or so above the food substrate.) Again, keep in a dark, warm place and cover with the tote lid shimmed up a half inch or so. The hatchlings will crawl down into the food. If you snap the lid on tight, the hatchlings will use the resulting condensation to crawl up the sides and escape from the tote. At 90F, the eggs will hatch out in two days or less - longer if it's cooler than that.

Author:  biobehaviorist [ Wed Feb 15, 2012 5:57 pm ]
Post subject:  Re: BSF project in Colorado

Right now my egg traps are little plastic cups with coffee grounds and other food material. I've been keeping them moist daily with a spray bottle because humidity is an issue here, the coffee grounds can turn to dust after a few days. I would expect the tiny little larvae have to find something wet before they dry out and perish. I have cardboard pinned to the top of the cups, suspended above the wet stuff below so I'm expecting them to lay eggs in the cardboard and the larvae to go down into the cup for moisture and food.

Author:  BorealWormer [ Wed Feb 15, 2012 6:16 pm ]
Post subject:  Re: BSF project in Colorado

biobehaviorist wrote:
...I have cardboard pinned to the top of the cups, suspended above the wet stuff below so I'm expecting them to lay eggs in the cardboard and the larvae to go down into the cup for moisture and food.
I think you've got both bases covered then - it won't matter if the eggs are deposited directly in the cups.

I also have problems maintaining humidity and resorted to using lids on the cups. Each had a hole to allow the BSF access.

Remember that cardboard is primarily used by researchers to measure the rate of oviposition as determined by recording egg clutches deposited daily. To be able to make this measurement limited wet attractants are provided with corrugated cardboard strip or rolls placed close by. BSF will not lay eggs in wet material but want their eggs close to the attractant and so use the cardboard ovipositing in the flutes. The cardboard is replaced daily and the numbers of egg clutches recorded.

In an enclosed system cardboard not really required unless you want to document the rate of oviposition..

Author:  BorealWormer [ Fri Feb 17, 2012 4:50 pm ]
Post subject:  Re: BSF project in Colorado

Tarvus wrote:
... I suspect it's more a case of them seeking a bit of moisture or a humid environment.
Thought I'd mention my recent experience although there was only one larvae involved. Recently I transferred the new larvae from the cups of used coffee grounds where they hatched to a rearing tub. In amongst the 4mm larvae was one lone 20mm dark prepupal larvae that must have migrated out of the rearing tub, across the animal bedding on the bin bottom and up into the cup of moist coffee grounds.

Edit to add I found another dark larvae in each of the wet cups of UCG today so there must be something to this attraction to a humid environment.

Author:  biobehaviorist [ Wed Feb 22, 2012 2:29 pm ]
Post subject:  Re: BSF project in Colorado

Another update as of 2/21. We have eggs! On one of the cups, there were eggs deposited not in the cardboard gaps, but underneath the clothespin in the space of about a dime. since last week the soggy bagel and banana have now turned to a nice filamentous, technicolor pile of mold, on top of the UCG. I was curious is this mold a concern? should i remove it to encourage the grubs to get to the UCG or will they work their way into it anyway?

Author:  BorealWormer [ Wed Feb 22, 2012 3:28 pm ]
Post subject:  Re: BSF project in Colorado

biobehaviorist wrote:
We have eggs!
Great stuff :D

Quote:
I was curious is this mold a concern? should i remove it to encourage the grubs to get to the UCG or will they work their way into it anyway?
I don't think the mold is anything to worry about but I guess it couldn't hurt to remove it (file that under 'better safe than sorry').

Author:  biobehaviorist [ Wed Feb 22, 2012 6:38 pm ]
Post subject:  Re: BSF project in Colorado

Some of the eggs have now hatched, as I closely observed a miniature piece of rice start moving along the side of the tote. I was expecting them to go down into the cups, but they are probably going to be all over the bin and For all i know, an adult could have just laid eggs in the sawdust. However, my plan is to give the bin another week or two for all of the adults to die off. There are even still a few active prepupae crawling around and I witnessed and adult comically hitching a ride on one of the grubs ascending the damp sides of the tote 8-). Inside the tote it hit 45C today so everything was very active. I will be reconsidering the bin design and locatino for the warmer months ahead.
I think the newly hatched larvae will begin to feed off the dead adults and other mushy bits laying around the tote and I will add a few food scraps to the tote as well, in attempt convert it from a breeder to a composter so the new grubs can grow a bit bigger before I collect them and set up a new container. Overall, I'm really pleased with how this has gone so far and want to say thanks for everybody's help (especially BW) . In retrospect I would have probably ordered grubs of varying sizes, to stagger their production instead of doing it all in one big wave. More updates in the weeks to come.

Author:  BorealWormer [ Wed Feb 22, 2012 8:07 pm ]
Post subject:  Re: BSF project in Colorado

Glad you've got the next generation started :D
biobehaviorist wrote:
In retrospect I would have probably ordered grubs of varying sizes, to stagger their production instead of doing it all in one big wave. More updates in the weeks to come.
The fellows on the German reptile forum mention alternating between mostly larvae and mostly flies too. For me this second generation will spread it out enough that I don't get the boom and bust. There were still a few large white larvae in the rearing tub 45 days after the first flies emerged. I counted about 30 flies today so they're still emerging. All of this generation are from eggs laid around the end of September 2011.

I believe the length of their life cycle is determined to a large degree by the temperature of their habitat. Mine are kept at about 21°C and so grow slowly.

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