Wikipedia misrepresents black soldier flies

Bad Wikipedia!

Update 8/25: Since I’m aware that anyone can modify a Wikipedia entry I went there to investigate the process. I assumed there would be a detailed system of presenting information and waiting for a consensus before changes would be allowed. Nothing of the sort. Registration was simpler than with most internet forums and it was automatic and instant. I registered and then began looking for the form where I could make my recommendations for editing the black soldier fly entry. There is no such thing, but there is an edit button. I clicked “edit”, changed a few things and then saved it. That’s all there was to it. A 10 year old could do it. Wikipedia can be a valuable source of information, but it relies on consensus and this can lead to problems with obscure subjects such as black soldier flies. I will continue to edit this Wikipedia entry until it accurately depicts black soldier flies.

I considered deleting this post about Wikipedia since the issue will soon be resolved, however it can still serve to illustrate the problems with relying on Wikipedia as a reference source.

ORIGINAL POST:

First, it’s important to understand how Wikipedia functions.

This is from the Wikipedia entry about itself:

Wikipedia (pronunciation Spoken content icon) is a free,[5] multilingual, open content encyclopedia project operated by the United States-based non-profit Wikimedia Foundation. Its name is a portmanteau of the words wiki (a technology for creating collaborative websites) and encyclopedia. Launched in 2001 by Jimmy Wales and Larry Sanger,[6] it attempts to collect and summarize all human knowledge in every major language.[7]

Critics of Wikipedia target its systemic bias and inconsistencies[12] and its policy of favoring consensus over credentials in its editorial process.[13] Wikipedia’s reliability and accuracy are also an issue.[14] Other criticisms are centered on its susceptibility to vandalism and the addition of spurious or unverified information.[15]

SOURCE

Wikipedia is an open content “encyclopedia”, and here is their definition of open content:

Open content, a neologism coined by analogy with “open source“, describes any kind of creative work published in a format that explicitly allows copying and modifying of its information by anyone, not exclusively by a closed organization, firm or individual. The largest open content project is Wikipedia.[1]

In other words you, or I, or anyone else can modify any Wikipedia entry.

How does Wikipedia get black soldier flies wrong?

The problem with the Wikipedia entry for BSF at this time is that it’s very unbalanced and poorly referenced. You can click the image below to see a view of the entry as it was on 8/21/08.

Wikipedia image of BSF b

(click to enlarge)

Of the six bullet points about BSF I believe that one is incorrect and another is misleading:

  • The larvae can be destructive pests in honeybee hives

I have heard this before, probably from people who have read this Wikipedia entry, but I have found no research to back it up. All I could find was a reference to BSF larvae inhabiting abandoned hives found in the walls of houses. I can’t imagine how a BSF adult or larvae could survive in an active beehive. BSF are truly defenseless creatures that lack stingers and the adult flies don’t even have functional mouth parts.

I tried finding documentation of this claim from the three sources the article sites as references. The first study didn’t mention bees and in fact the title of the study refers to BSF as “a Non-Pest Native Fly”. The second source deals with forensic science and refers to black soldier fly larvae collected from a couple of  bear carcasses. The third source is a print article and I couldn’t locate a copy of the July 2007 issue of Reptiles magazine.

If anyone finds evidence that BSF can be “destructive pests in honeybee hives” please present it to me because I don’t believe it.

  • The larvae may sometimes cause intestinal myiasis or pseudomyiasis in humans. See this case in Costa Rica[1]

Whoever wrote this did use the word “may”, but an entry like this is unbalanced if it doesn’t describe how rare this potential event actually is in the case of BSF. The point of an encyclopedia is to present information in such a way that the reader gains a basic overall understanding about the subject. Due to the sensational quality of myiasis this statement it is likely to be overemphasized by the average reader. Anyone who clicks on the word myiasis in this Wikipedia sentence will be taken to a page that describes this very disturbing condition where a fly larvae inhabits the inside of person. This is sensational, but not balanced reporting in the case of BSF.

It’s possible that a BSF larvae will survive in a human gastrointestinal tract if it’s swallowed whole which is why I always recommend chewing them well. :) I found references to a few cases worldwide involving BSF over the last 50 years, and in those few cases no serious or lasting damage was attributed to BSF larvae.

The fact is that this possible occurrence is exceedingly rare and would most likely be caused by people eating from garbage cans. A BSF female seeks out rotting food on which to lay her eggs, not fresh. Furthermore, there is research that suggests that BSF larvae actually control pathogens in waste such as salmonella and E coli. That means a person who ate from garbage inhabited by BSF larvae might be spared a severe illness or even death.

How does Wikipedia describe rattlesnakes?

This is the entire overview section from the rattlesnake entry at Wikipedia:

There are approximately fifty species of rattlesnake, with numerous subspecies. They receive their name for the rattle located at the tip of their tails. The rattle is used as a warning device when threatened. The scientific name Crotalus derives from the Greek, κρόταλον, meaning “castanet“. The name Sistrurus is the Latinized form of the Greek word for “tail rattler” (Σείστρουρος, Seistrouros) and shares its root with the ancient Egyptian musical instrument, the sistrum, a type of rattle.

Most rattlesnakes mate in the spring. All species give live birth, rather than laying eggs. The young are self-sufficient from birth. As they do not need their mother after birth, the mother does not remain with her young.

No mention of venom or human deaths? If you didn’t already know that rattlesnakes are dangerous you might think they use their rattles to calm little babies. Yes, we all know that rattlesnakes are dangerous, but this still represents unbalanced reporting by Wikipedia. You have to read halfway down the lengthy entry  to the “Safety and identification” section to find a reference to rattlesnakes biting humans. You would think that the the safety section would mention the fact that these beautiful animals can be deadly to humans, but you would be wrong.

Wikipedia entry for Rattlesnake

And finally, the black soldier fly photo from Wikipedia:

Wikipedia image of BSF

I’ve seen a lot of images of black soldier flies and the one at Wikipedia is the only one I would call sinister looking. I’ll bet the vast majority of people who see that image immediately assume that the BSF is stinging the tree. Could these “soldiers” be so aggressive that they sting trees for no reason!? In fact that is a female black soldier fly laying hers eggs. Unlike disease carrying flies, BSF prefer to lay their eggs above and away from the food source and not on it. BSF mimic wasps in appearance as a defense because in reality they are totally vulnerable creatures.

To put Wikipedia’s accuracy into even greater doubt place your cursor over the original image on the Wikipedia page. You will see the file name for this photo which is “Wasp 1454″. If you don’t know the difference between a wasp and a fly you shouldn’t be creating encyclopedia entries.

Doesn’t everyone know to take Wikipedia entries with a grain of salt?

Well hopefully anyone who reads this post will! :)

Black soldier fly composting in the frigid north

frigid north

Black soldier flies are common in tropical and subtropical regions, but their range extends to  the most northern states of the continental U.S. You can easily operate a BSF bio-composting unit in northern states during the warm months, but you can also maintain the colony through the colder months with a little extra effort.

A black soldier fly colony generates it’s own heat

Maintaining a BSF unit in cold weather is possible because the metabolic action of the larvae eating creates heat as a byproduct. Under cold conditions keeping the colony at the optimal temperature range of 85° - 100°F (30°-38°C) is as simple as consistently feeding them and placing an insulating material directly on top of the pile. Simply remove the insulating material, add the food scraps, and then replace it. It’s important to feed the colony consistently in cold weather because without food the temperature will drop and the colony will become dormant.

Maintaining a BSF colony during extended periods of sub-freezing weather is possible, but it may be more than you wish to get involved with. In that case you can enjoy BSF culturing up to the point where the weather in your area makes it difficult and then resume in the spring.

Process more food scraps, harvest less larvae

In cold weather the time it takes BSF larvae to mature increases from the usual few weeks to a period of up to several months. The colony has little or no crawl-off of mature larvae and that enables you to continue bio-composting without the need to replenish the larvae via visiting females.

In warm weather the colony has a tendency to overheat, so in cool weather the larvae are able to consume even more food scraps.

How adventurous are you?

I don’t recommend bringing the BSF unit into your living room, but why not try keeping it in the garage or a shed when the temperature drops? Sure, a few larvae might get out, but so what? The adult fly will just emerge from it’s pupae in the spring and then you’ll have the pleasure of gently capturing it and releasing it outdoors. They are harmless creatures after all.  I don’t think a heated space would be the best choice though, because it might trick the larvae into developing too quickly. I would guess that 40° - 60°F (5°-15°C) is a good range to try testing this theory, and of course you would need an insulating disc of some sort to keep the colony warm.  The degree of insulation would depend on the ambient temperature in the space.

I’m cursed with living in an area that rarely gets cold so if you try this experiment please let me know how it goes. I would love to post photos of your set up (if it works :) ).

Black Soldier Fly cultivation - “nuts and bolts”

nuts and bolts 4

The purpose of this post is to feature a blog that is valuable to anyone researching black soldier flies. It’s called BioSystems Design Weblog and below is an excerpt from their “about” page.

About BioSystems Design

BioSystems Design LLC. is dedicated to the transformation of what was previously considered waste into valuable products.  Our institutional knowledge and designs are based on nature, as nature is the premier designer of BioSystems that use waste as production inputs.

Our studies of nature and Biosystems are conducted in Bogotá, Colombia, at our two research laboratories, with our prestigious partner organizations, La Universidad Nacional de Colombia and Universidad de La Salle.

BioSystems Design LLC.  maintains close partnerships with ESR International and Otterwasser Gmbh.   Our commitment to ESR International is the design, construction, and operation of an industrial production process that feeds crop and food waste to larvae, harvests that larvae, cooks it, pulverizes it, and sells the high protein larvae-meal to animal feed producers.

Our commitment to the German wastewater consultancy, Otterwasser Gmbh, is to sell, build, and operate their innovative energy generation and wastewater treatment systems in the United States.

BSF post from their blog:

Black Soldier Fly: Compiled Research On Best Cultivation Practices

The following represents the “nuts and bolts” facts relevant to Black Soldier Fly cultivation which were found buried inside of research texts. The key distinguishing factor is that they are organized by environmental considerations (in bold). Where inconsistencies are found they are noted. Assistance, suggestions, along the lines of additional sources, inconsistencies, and added environmental considerations are highly welcome. I hope to make this a very active post.

Take the black soldier fly challenge

I believe black soldier fly larvae represent the most logical method for dealing with the constant stream of putrescent waste that humans create. Putrescent waste is anything that gets putrid (rots) and is mostly wasted food.  BSF aren’t magic but it’s hard to imagine a much more efficient solution to a growing problem.

adult bsf

Bio-conversion

The process of feeding organic wastes to black soldier fly larvae is called bio-conversion. That’s because the process doesn’t exactly eliminate the garbage, it converts it into BSF larvae. Rotting garbage is a liability and BSF larvae are a valuable asset. You can read more about bio-conversion HERE.

BSF prepupal larvae

Generally accepted data about black soldier flies and larvae

  • They are not associated with the transmission of diseases.
  • They don’t bite or sting and they avoid human habitats.
  • Their presence in waste deters or even eliminates house fly reproduction in that waste.
  • Larvae rapidly consume almost any organic waste except for high cellulose items like yard waste or paper.
  • Larvae reduce the volume of household food waste by up to 95%.
  • A 2 foot (60cm) container of larvae can process several pounds of household food waste in 24 hours.
  • When larvae mature they will self harvest using a simple ramp system.
  • Live larvae are very nutritious and are readily consumed by many different animals (pigs, chickens, reptiles, fish, etc).
  • Meal made from dried larvae is roughly equal to Menhaden fish meal, a valuable and widely used ingredient in animal feeds.

The challenge

I’m making the claim that bio-conversion of putrescent waste with BSF larvae is the best possible method for processing putrescent waste. The challenge is simple, state any significant problem that might be caused by using BSF to convert our organic garbage into nutritious animal feed.

Let’s not wait

Burying our food waste in giant rotting mounds is ridiculous given the elegant solution represented by bio-conversion with black soldier fly larvae. The technology already exits and represents the essence of sustainablity. What in the world are we waiting for?

Collecting the immature larvae

This method doesn’t involve the dark, prepupal larvae which are self-harvesting

The coffee colored BSF larvae (prepupae) are the final stage before pupation into adult BSF. To our advantage they are programmed by nature to crawl away from the food source in search of a suitable pupation site. In a properly designed BSF unit these larvae crawl up a ramp and drop into a collection bucket where they will live for weeks without any maintenance.

The method described below is for harvesting the earlier stages when the larvae are actively feeding and growing. It doesn’t work for the mature larvae because they don’t eat therefore aren’t attracted to the bait in the collection container. It works very well for the light colored immature larvae.

The Immature Larvae Collection Device or ILCD (old butter tub)

Take a cheap container and cut some small holes around the bottom edge.

immature larvae collector with fish pellets

(click on images to enlarge)

Add something delicious (any food scraps will do), and simply place it on the surface of the compost. I used fish food because I’m training my fish to eat it and this is a good way to introduce them to the flavor (I feed the larvae to the fish). Just about anything will work, but drier items might make handling the collected larvae easier.

The photo below was taken 2 minutes after placing the tub on top of the compost.

immature larvae collector after 2 min

This is after 11 minutes.

immature larvae collector after 11 min

The photo below was taken 40 minutes after adding the container.

immature larvae collector after 40 min

This quick harvest totaled about 2 cups (.5 litre) of small to medium larvae. I don’t have many large larvae at this time due to the crash I caused in the colony a few weeks back. I do have a lot of larvae, just not large ones yet.

Feeding black soldier fly larvae to Redear Sunfish

redear sunfish preparing for supper

I’ve been feeding BSF larvae to my redear sunfish (shellcrackers) everyday for about a week and they are taking them with enthusiasm. They have a preference for the immature larvae over the dark prepupal larvae, but they still eat the dark ones pretty well. I think the prepupal larvae might be more foreign to them than the light colored larvae, but I think with some conditioning they will eventually accept  them just as well. There are some individual fish that already take the prepupae well which is why I suspect it isn’t a taste issue or something like that.

(Wow. That video quality is terrible. I’m open to suggestions if anyone would like to offer some advice about uploading video. I’ll leave this up for now, but I have to do something! I tried blip.tv and PhotoBucket which were better quality, but the embedded players for these sites ruined the xhtml validation for my blog, the YouTube videos don’t.)

Here’s a link to a better quality version of the same video at Blip.tv - VIDEO

Update - August 14

These fish are in a pond that was built in January 2008 and I only stocked 24 adult redears. (I also stocked 110 very small redears in late March and you can see a few of them feeding with the larger fish in the video) At first when I began feeding them BSF larvae the fish were concentrated in one area of the pond because they were on spawning beds. This made it very convenient to hand feed them, but I assumed they would disperse once the spawning season passed. Well, the spawning seems to be over and they’re still concentrated in the same spot, and I’m pretty sure it has something to do with the daily offerings of black soldier fly larvae. Lately when I walk up to the feeding area I see the fish lining up just off the bank of the pond about one meter from the water’s edge. All fish are oriented on me as they wait for the rain of tender BSF morsels. They will swim into water that is only a few inches deep to snatch up the larvae. Previously I was unaware of the popularity of fly larvae as fish bait, but now I can understand why they are so effective.

If you’re a sensative person you may hesitate at the idea of sacrificing the larvae to fish this way but there is another way to look at it. In nature fly larvae have a high mortality rate and the balance of the population is based on the vast majority of them not surviving to reproduce. Two BSF can produce between 500 and 900 eggs depending on which report you read, and to maintain the normal population only 2 of those several hundred will survive to lay more eggs. I address this issue in more detail here: Feeding black soldier fly larvae to other animals

My new (ESR/ProtaCulture) BIOPOD™

My first BioPod

After working with and blogging about black soldier fly larvae for over a year I finally have one of the first BioPods. For the past year I’ve been getting by with my homemade unit and I’m looking forward to testing this product. With that previous experience I’m pretty familiar with the shortcomings of my unit and from what I can tell by looking, the BioPod addresses those problems.

I’m starting this colony from scratch

I already have a colony of BSF larvae established, but I want to take this opportunity to start a BioPod from scratch. On one hand it seems like I’ll have an advantage starting this new colony because I have an established BSF population on my property, but that may not be an advantage. My existing colony which is 200 feet (60 meters) from my new BioPod is a powerful attraction to any female BSF looking to lay their eggs. BSF larvae do not have a strong or unpleasant odor, but their scent is easily picked up by the adult females.

The bait

The BioPod user’s guide recommends starting your colony with normal household food scraps except for meat or fish. It’s not a problem to feed meats or fish to an established colony, but before that stage those items will attract too many unwanted critters. I started my first colony using assorted scraps, but for this unit I’m using only dry dog food. I added 2 cups (.5 liters) of it, slightly moistened. The humidity where I live is usually 50% or higher so I don’t think I’ll need to wet it further. The purpose of wetting it in the first place is to enhance the smell and it may not even be necessary. The reason I’m testing with the dog food is because some types of food scraps start to look nasty after a few weeks and the dog food is fairly stable. In the end it probably doesn’t make much difference, but it’s hard for me to follow instructions sometimes. :)

JULY 10

This is the day my BioPod arrived. I set it up in about 20 minutes, added the bait, and so far that’s all I’ve done. It’s important to deter ants from entering the BioPod so I’m going to treat the legs of the stand with a small amount of Bug Stop.

JULY 15

It’s been raining a lot lately and that seems to slow down the BSF adults. I haven’t observed any BSF or seen any eggs on the new BioPod yet. This morning when I checked it there were a few house flies on the lid and I could smell the dog food from outside. Inside there were a few fruit flies and nothing else.

JULY 20

Still no sign of black soldier flies in the BioPod, even though they’re active only a few hundred feet away.  I guess this reinforces the idea that if you maintain a BSF colony that you won’t have them all over your property. I’ve seen a few house flies on the BioPod lid but none inside. This may be because they aren’t willing to enter the small opening in the BioPod. My homemade unit had a fair amount of house flies entering it at this stage.

The dog food I used as an attractant is beginning to mold and I don’t think it was necessary to moisten it. Still not bad for 10 days in the summer though. :)

It can be frustrating waiting for the BSF to show up at your BioPod. I think the key is getting that first female  to lay her eggs in your BioPod. Once that happens I think the others will quickly follow.

JULY 24

Still no luck in the new BioPod and I may have a clue why it’s taking this long, even with the healthy BSF population on my property.

frog on the BioPod lid

I’m sure this one frog isn’t the only reason it’s taking a while and it may be the other colony I have on the property is getting all of the attention. Still, that is one well fed frog. :)

JULY 27

Okay, first of all, the frog was back! The frog from the photo has some unique markings and I believe the one I saw today was the same frog. The first time I moved it about 50 feet, this time I tried 100. :)

Other than that I want to say UEREKA! I now have BSF eggs in my new BioPod. I’m surprised how long it took, but as I mentioned earlier I believe my other colony was attracting most of the females.

It won’t be long now!

Black soldier fly eggs on egg disc

(egg disc removed from BioPod for photo)

AUGUST 1

I have a few different types of larvae feeding in the BioPod now which are too large to have come from the eggs in the photo above. I think I’ve seen one of these species in the past when starting a BSF colony, and I think it may be one of the other soldier fly variaties. Here’s a photo of that fly:

possible soldier fly - not bsf

(unidentified fly - not bsf)

There are over 200 members of the soldier fly family (Stratiomyidae) in North American, but I assume the other soldier flies won’t work well for bio-composting.

I’m fairly certain some of the larger larvae feeding in the BioPod are black soldier fly larvae, so it shouldn’t be long before they become the dominant species.

Frog removal is becoming a daily chore. :/

AUGUST 2

I may have been too conservative with the food scraps added to the Pod so far. I’ve limited the food source to the original few cups of dry dog food put in at the beginning. Since there are larvae now present I decided to add more food today. When I removed the BioPod lid I was happily surprised to see 4 female BSF laying eggs. If they all survive that could be a few thousand larvae.  Two of them kept laying will I poured the sloppy scraps in.

AUGUST 10

Today there were prepupae in the collection bucket. Prepupal larvae (prepupae) are simply the mature, dark colored larvae that are in the final stage before they pupate and change into adult black soldier flies. Although the light colored immature larvae sometimes migrate out of the BioPod the majority are these prepupal larvae.

prepupal black soldier fly larvae

Above: The BioPod collection bucket

The number of larvae actively feeding in my new pod is steadily increasing as is to be expected. I’m short on food scraps so I’ve been feeding this colony a type of hog feed that is made from cornmeal. Ideally I’ll find a source of food waste to use but for now I don’t have the time to find it or fetch it. : /

bsf colony on August 10, 2008

The cutest black soldier fly researcher EVER!

(Sorry Dr. Sheppard, Dr. Olivier and Dr. Tomberlin…)

Alana is hands down the cutest of all black soldier fly researchers. Apparently her folks forgot to tell her that BSF larvae are yucky! Good parents. :)

Anyone concerned about Alana handling BSF larvae may want to read this which references scientific studies showing that black soldier flies are not carriers of diseases. There is also a brief discussion in the comments for this post.

black soldier fly emerging from it’s pupa

I think I spent over six hours shooting video to capture this five second long event. I’m not really sure what value it has other than general coolness. :)

After exiting the pupa it ran to the outside of the bowl and spent about 10 minutes inflating it’s wings. Soon I hope to record that process and speed the video up.


The BioPods have landed!

ufocrash

The first shipment of BioPods has arrived at the ProtaCulture warehouse and will begin shipping out soon. I can’t wait to retire my homemade BSF unit!

I crashed my pod

Hindenburg

Experiment causes black soldier fly larvae colony to crash!

Okay, maybe the Hindenburg image is a little extreme, but it’s difficult to get attention on the internet these days. The good news is that bringing my BSF colony back into balance shouldn’t be all that difficult. In the past when I’ve run into problems I’ve corrected them by lessening the amount of food scraps that I introduced into the unit, and that is what I’m doing currently.

BSF larvae can eat almost anything

BSF larvae will consume almost anything organic except high cellulose materials like woody stems and grasses. They will quickly eat just about anything that has available calories including food waste that would probably be toxic to humans, like decomposing fish for example. The fact that they are able to efficiently digest such a wide range of material is what makes BSF larvae such a powerful tool for processing waste.

About those decomposing fish…

I help my neighbor manage the small pond behind his house. Recently several of his fish died and I did him the favor of removing them a few days after they floated to the surface. The fish weighed about 5 pounds (2.3 Kg) total and by the time I removed them they were already very stinky. Instead of disposing of them like a normal person I decided to see how quickly my BSF would process them. I’m happy to report that my small colony completely consumed the fish within about 2 days. I am unhappy to report that after I added the decomposing fish to my BSF unit it began attracting blow flies and house flies.

Black soldier fly larvae produce an info-chemical that repels pest flies, but there are limits as this test illustrates. The odor of these decaying fish was a powerful attractant to undesirable flies and it overpowered the repellent properties that are normally very effective in a BioPod.

I’m currently using a homemade BSF unit (not any more!) because BioPods are not yet available. My homemade unit is a less efficient design and I’m sure that this made my recent problem worse than it would have been. My unit doesn’t deal with liquids as well as a BioPod so the problem was less contained than it would have been with the commercial product. I will be happy when the first BioPods arrive.

And now the good news

Even the extreme imbalance created by adding these decaying fish to my colony can be corrected with a little time and care. Of course I’m more cautious about sanitation while the pest flies are present, but in reality I don’t need to do much other than stop feeding the colony and let the other flies cycle through. It’s now been about 5 days since I added the fish and my colony is almost back to a balanced state again.

You can avoid this type of problem easily

My test with the decayed fish was something that most people wound not have tried, but I’m involved in testing the limits of this technology. If you use BSF larvae to process your normal household food scraps it’s very unlikely that you’ll experience anything like the crash I just created. You can even add food that is quite spoiled and you shouldn’t have a problem like my recent experience.

Black soldier flies are not vectors of human pathogens

Can I guarantee that you won’t get sick from contact with black soldier flies?

There is no species of animal on Earth that could live up to that guarantee, but researchers agree that black soldier flies (Hermetia illucens) are not disease carrying pests like common filth flies.

handful of black soldier fly larvae

Black soldier flies are different

I can understand people’s revulsion at the thought of flies in general. The common house fly is associated with 277 disease organisms. On the other hand, BSF have been the subject of many scientific studies and they are not known to be transmitters of disease causing pathogens. I’ve read dozens of articles about using the larvae to process manure and about feeding them to animals and I’ve never come across any warnings about handling BSF. It’s easier to find information about humans transmitting pathogens than about BSF doing so. You can, however, find some nice photos of researchers holding big handfuls of BSF larvae and smiling broadly (the researchers that is). There are several aspects of the BSF life cycle that result in their non-pest status.

black soldier fly blog logo

All flies emerge sterile

The process of pupation results in all flies emerging free of pathogens. It’s the lifestyle of the adult flies after that point that makes the difference.

BSF adults (winged stage) only live for a few days as opposed to 30 or more days for house flies. Because of their short lifespan adult BSF don’t need to eat and in fact don’t even have working mouth parts. For that reason they rarely enter human habitats and they don’t compete with humans for food. House flies must eat so they cycle back and forth between waste material and our food. It’s that cycle that results in the transfer of pathogens and it’s the absence of that behavior that keeps BSF relatively clean.

After emerging, the adult BSF mate and the female flies away in search of a suitable food source to lay her eggs near. The female’s preferred site for depositing her eggs is close to, but not on the food source. Eggs laid on the food source will have a high chance of being inadvertently consumed by already feeding larvae. This is another characteristic that contributes to the BSF status as a non-pest species.

Unlike many other flies, BSF adults do not go into houses, they do not have functional mouth parts, they do not eat waste, they do not come into contact with waste, they do not regurgitate on human food, and consequently, they are not associated in any way with the transmission of disease. They do not bite, bother or pester humans in any way. - Dr. Paul Olivier

SOURCE

The amazing digestive system of BSF larvae

In contrast to spreading disease there is evidence that the presence of BSF larvae can reduce pathogens in waste material.

Bacteriological interactions associated with manure digestion by maggots are favorable. Maggots are competitors with bacteria for nutrients and often reduce bacterial numbers greatly, or eliminated them altogether (Beard and Sands, 1973; Sherman, 2000). Maggots may consume and digest microorganisms, and produce antibacterial and/or fungicidal compounds (Landi, 1960; Hoffmann and Hetru, 1992; Levashina et al., 1995 and Landon et al., 1997). As maggots reduce pathogens in manure they may make it safer for organic vegetable production.

From the same article:

Flies that have been used experimentally to process manure include house flies (Musca domestica), face flies (Musca autumnalis), blow flies (usually Sarcophaga sp.) and the black soldier fly (Hermetia illucens). Except for the black soldier fly (Furman et al. 1959), all of these are considered pests as adults due to their disease vector potential, behavior and preferred habitats.

Preliminary studies with black soldier fly larvae indicated a reduction of pathogens in an artificial medium or manure innoculated with larvae. Numerous studies using dried, rendered and fresh maggots as animal feed have revealed no health problems resulting from this practice. Preliminary bacterial culturing of self-collected soldier fly prepupae from a recent swine trial revealed no pathogens

SOURCE

BSF larvae lessen or eliminate the breeding of pest flies

When a food source has an established colony of BSF larvae other species of flies are rare or even absent. The larvae produce an info-chemical that alerts other flies to the fact that the source of food is already being dominated by BSF larvae.

Common sense about working with black soldier fly larvae

I’m not suggesting that black soldier flies or their larvae are perfectly sterile. You and I are not perfectly sterile. Pathogens are everywhere and it is common sense to wash your hands after working with BSF, just as you would after petting a dog or shopping at the grocery store.

Earthworms + black soldier fly larvae = composting²

Composting with black soldier fly larvae and composting with earthworms (vermicomposting) are not competing technologies as much as they are complimentary. I’m not speaking from personal experience or research, but I believe it because I was told this by Dr. Paul Olivier, the inventor of the BioPod and one of the pioneers of black soldier fly research.

earthworm on stone background

Add another hobby to the list

It was Dr. Olivier’s work that first inspired me to work with black soldier fly larvae, so his enthusiasm for vermiculture is enough to motive me to try my hand with worms. Apparently the friable compost that is a byproduct of BSF composting is a superior medium for raising earthworms. As soon as my larvae have produced sufficient compost I’ll start a worm bin.

Calling all earthworm enthusiasts

I would like to exchange ideas and information with anyone experienced in vermiculture and who is interested in incorporating black soldier fly larvae into their systems. Feel free to post a comment, send me an email, or better yet, join the BioPod forum and post in the Vermiculture section. The forum is brand new so it’s pretty quiet now, but it should be a good place to discuss these two composting techniques. I started a thread in the Vermiculture section and you can find it here.

Up the food chain - feeding black soldier fly larvae to other animals

toad stalking black soldier fly larva

In my previous post (below) I described how a person can develop something like affection for a colony of black soldier fly larvae (BSFL). If that’s the case then why do i enjoy feeding the larvae to other animals? A big part of it is the same pleasure I mentioned that you get from feeding animals in general. There is just something satisfying about watching animals eat, especially when you provide the food. I don’t feel like I’m being hypocritical, let me explain…

Maintaining a natural balance

Black soldier flies lay from 500 - 900 eggs in the few days they live as adults. In nature the vast majority of these eggs don’t live to reproduce, if they did it would lead to an unbalanced population. Assuming that there is one female BSF for each male, then the proper balance would be maintained if two of the several hundred eggs survived to reproduce. That’s a high rate of loss, just as nature intended.

In an uncontrolled setting the BSFL would be heavily preyed on by frogs, toads, birds, lizards, little furry things, etc. Protecting the larvae in a container serves us because we can employ them to process our food waste, but it does result in a much larger number of larvae surviving to the prepupal (last larval) stage. By feeding most of these larvae to pets, pond fish or wildlife we maintain a more natural balance.

toad eating black soldier fly larva

Enjoy feeding local wildlife

By keeping a BSFL bio-composting unit you convert what would have been nasty landfill into a nutritious, and I assume delicious, source of food for your local wildlife. As in nature you can allow a small number of larvae to pupate, but you also have a great opportunity to enjoy feeding critters.

There is a long list of birds that love to eat BSFL, and there are feeders that make it relatively simple. You can search for information about feeding mealworms to wild birds and simply use black soldier fly larvae in place of the mealworms. Check the link below for more information.

Web search: “feeding birds mealworms”

As you might guess from the photos in this post I often feed the local toad population with BSFL. One nice thing about feeding the toads is that they’ll eat while you’re fairly close to them. I’m sure it’s serious business to the toads, but it’s still fun to watch the way they “stalk” the larvae. Keep in mind that some of the larvae I offer to the toads and other wildlife will escape and survive.

The joy of feeding animals-nurturing black soldier fly larvae

As unlikely as it sounds, feeding a black soldier fly colony taps into the fun and satisfaction you usually experience feeding more “cuddly” types of animals. I believe most people will develop something like affection for the colony after a while. It’s true that some people feel initial discomfort with the larvae but this usually changes to appreciation after a short time.

black soldier fly larvae eating an apple

Appreciation for the colony

The affection I’m describing isn’t so much about individual larvae, it’s about the colony as a whole. When you keep a BSFL colony a relationship is created where you provide them with food and they provide the service of processing your garbage.

The end of guilt

… about wasted food anyway. Like most people I used to feel guilty when I mismanaged my groceries and ended up with wasted food. I still generate excess or spoiled food, but now I don’t view it as waste, instead it’s BSFL food. I no longer put it in plastic garbage bags and ship it off to rot in the landfill. What used to be discarded is now a source of great celebration for several thousand tiny creatures. (Yes I’m anthropomorphizing, there’s more to come too).

There’s a party goin’ on!

Just imagine what takes place when you toss your unfinished pancakes into the bio-composting unit. One thing I’m sure of, these little creatures love to eat. Maybe it’s not joy the way we know it, but it’s still rewarding to see the mad dash the larvae make to whatever delicious (to them) new scraps you supply. You can enjoy feeding most pets a few times a day, or even less for lizards, snakes, etc. On the other hand you can feed a black soldier fly colony anytime you want to. BSFL don’t replace a dog, or a cat, or a pet lizard, but few pets “appreciate” being fed as much as these fascinating creatures.

black soldier fly larvae eating an apple

Timing the transition-larva to adult black soldier fly


MAY 30

Today I harvested the first of the prepupal black soldier fly larvae from this year’s colony. At this stage their instinct is to leave the food source and find a suitable place to pupate. I don’t know much about this part of the BSF life cycle so I want to find out first hand. I put the harvested larvae into a closed container and I’ll be observing their behavior and changes, hopefully until the point where they emerge as adults.

testing black soldier fly development

When BSFL enter into their 5th and final stage as larvae they undergo some interesting changes. They go from a pale “grub” color to a dark coffee brown, and their mouth is replaced by a hook-like appendage to help them crawl in search of a good pupation site. They also empty their gut and excrete an antibiotic, a behavior which I find fascinating. A veterinarian friend of mine wonders if animals that eat the 5th stage larvae might benefit from ingesting the antibiotic.

Update MAY 31

Yesterday I placed about 15 prepupal BSF larvae into a one gallon container with some leaves and grass. If you click the photo above to enlarge it you can see a few of them. I added a handful of sand to one corner of the container and the larvae quickly buried themselves in it. One entered the sand but came back out and settled under a leaf.

I found a great poster by the Swiss Federal Institute of Aquatic Science and Technology (eawag), which outlines the BSF life cycle. BSF LIFE CYCLE

JUNE 2

They’re just laying there…

JUNE 6

*tap tap tap*

JUNE 9

I spoke with Dr. Olivier and he said that sand isn’t the best material for a pupation site. He recommended using sawdust to house pupae. He also puts some in the BioPod collection bucket to help keep it dry. He told me about a hamster bedding that works well, I think it was Aspen Bedding.

My pupae are still pupating…..

JUNE 19

Still waiting!

JUNE 26

Today I noticed adult BSF emerging from the pupae for the first time. It’s very possible that they started coming out before that but what can I say, I’ve been busy. :) I tried to photograph the process of the adults emerging but it happens very quickly. I checked on the pupae at one point and I noticed that an adult had it’s head out of the casing. I ran for my nearby camera and in the 20-30 seconds it took me to return the fly was already out and expanding it’s wings.

newly emerged black soldier fly


newly emerged black soldier fly 2

getting started - Attracting the BSF

To establish black soldier fly larvae (BSFL) you first need to attract the adult (winged) females so they can lay their eggs. To do this you need to bait them with some type of food.

black soldier fly bait box

Types of food for baiting BSF

You may use almost any food scraps, but I’m experimenting with different types to see which are the best. To find the bait the flies will need to be able to follow a scent trail, so items like vegetable peels or bread might not be the best choice. You may not attract the BSF right away so choosing a type of bait that won’t spoil too quickly may be a good idea. When I started a new colony this year I put out dry dog food (slightly moistened), used tea bags, refried beans, cottage cheese and coffee grounds. The teabags helped hold in moisture and the BSF like to lay their eggs on paper. I’ve noticed that the larvae seem to like coffee grounds so I thought they might be good for attracting adults. I kept this bait outside in fairly warm weather for two weeks and it never did get too nasty and it worked pretty well also. I think it’s a good idea to keep the bait moist for two reasons; the smell will be a little stronger (better attractant) and any eggs may develop more effectively.

Bait boxes

This year instead of putting my BSF bait directly into the BioComposter I tried putting out four individual bait boxes (see photo above). I made them by cutting the ends off of 12 pack soda cartons. Since I added water to the bait everyday it would have been a good idea to reinforce the bottoms with tape, but they held up just long enough. One reason I tried these boxes was to make it easier to swap out the bait if it spoiled too much. The main reason I tried it was so that I could easily move the bait to different areas. I think one of the best places I found was near a garbage can that was a little past the point when it should have been picked up. I moved the boxes into a closed container at night because the BSF aren’t out then. In fact, I’ve rarely seen one laying eggs before noon, they seem to be active during the hottest part of the day. Maybe that will change as we move into summer.

Once you have established a balanced colony of BSF larvae the number of houseflies near your colony will be dramatically reduced. Most likely you will have to put up with them until then. Either way it’s wise to wear latex gloves when handling the boxes. With an established BSF colony I usually just wash my hands immediately after working with them. Unlike houseflies, black soldier flies aren’t associated with the transmission of disease.

bsf-bait-near-garbage-can

After about a week I was seeing a good number of BSF laying eggs in the bait boxes so I moved them all into my BioComposting unit. Two weeks after setting out the bait I removed the bait boxes. The photo below shows my progress at that point.

bsfl-two-weeks-after-beginning

Trial and Error - Starting My First BSF Colony

I put out my first bucket of food scraps to attract black soldier flies in the spring of 2007. I soon observed the adult flies laying eggs in my bucket so I assumed that in a few days I would see larvae.

The literature I’ve read states that BSF eggs will hatch in roughly 100 hours.

After six days of seeing BSF in my bucket I had observed what I correctly assumed were BSF eggs, but still no larvae. The evenings had been cool and I imagined that temperature was the limiting factor. I took this photo on the sixth day and you can see a group (clutch?) of eggs which are about 1/2 inch (12 mm) across:

bsf eggs on cabbage

More than two weeks after observing BSF all I had to show was a few fruit flies and some dehydrated food scraps. I wasn’t even seeing BSF anymore. At that point I began to lose interest in the project and I stopped checking the bucket on a daily basis. We were experiencing drought conditions then and the last time I had checked the bucket I didn’t even replace the lid. We finally got a good rain but since I had lost interest I didn’t bother checking the bucket. A few days after the rain I passed by the bucket and noticed some flies buzzing around. I took a closer look and saw that they were black soldier flies. I looked inside the bucket to see some sloppy food scraps, and finally, BSF larvae.

first batch of black soldier fly larvae

black soldier fly larva and a penny

The fact that some of the larvae were almost full size seems to indicate that they had hatched even before the rain. Maybe the dry conditions didn’t stop the development of the eggs but instead just slowed it down and possibly limited the number of survivors. I think it may be best to keep the food scraps shaded and moist to help the eggs develop. Also, when the larvae first hatch they’re very small and it won’t be easy to see them for several days.

My First Attempt to Attract Black Soldier Flies - May 2007


As soon as I realized that black soldier flies were present around my home I put some food scraps into a bucket with a lid and cut a few small holes into the sides.

my first bucket of black soldier fly bait

BSF will crawl through a small opening to access a food source for their eggs. They don’t eat in their winged stage which is referred to as the adult stage. In fact, they don’t even have fully functional mouths because they only live a few days, just long enough to mate and lay their eggs.

I initially put out dog food, cottage cheese, bread, and assorted fruits and vegetables. Note: You can and probably will also attract ants (and most importantly, dogs) with this type of mixture so do what you can to keep these undesirable animals out of the bait. Within a few hours I had a few ladies (female BSF) checking out the offering and depositing eggs.

black soldier fly laying eggs on cardboard


If you look at the left side of the bucket in this next image you can see a BSF just before it entered the bucket through the small hole.

black soldier flies entering bait bucket

Be sure to keep the container with your food scraps out of the direct sunlight or you may overheat the larvae. If this happens they will evacuate the container if possible and if not they may die. I learned this the hard way.

An established and properly balanced container of Black Soldier Fly larvae will not have a bad odor. BSFL will consume the food scraps so quickly that it doesn’t have time to develop the bacteria that causes bad odors. If you overload the colony with food it can begin to smell before it’s eaten. A two foot diameter (60 cm) BioPod can process 5 kg (11 lbs) of food scraps each day.

Boy Meets Girl (fly) - my first encounter with a Black Soldier Fly

possible-black-soldier-fly-wtrmk2

In May of 2007 I was sitting at the computer in my home office researching black soldier flies. I had not yet seen one at that point in time, at least not that I was aware of. It was a warm south Georgia spring day and I had left the door open. A few bugs flew in and out, but it was just too nice to close the door. One bug in particular was rather loud as it buzzed at the window apparently looking for a way out. I’m in the habit of photographing insects that I find around the house so I snapped a pic of this bug. I went back to my research and entered “black soldier fly” into Google and clicked “search images”. As you’ve probably figured out already the “bug” that had entered my office and buzzed my head as I did the search was a black soldier fly. In the year that I’ve worked with them since there has been only one other time that a BSF entered my office. The photo above is the BSF from that day, the first that I had seen. And, yes, I should clean the windows more often…

One of the best ways to identify a Black Soldier Fly is to observe the white legs, or tarsi.