Mythbusting black soldier flies

Sep 152008
 

bsf-magnifying-glass-b

There are more than 100,000 species of flies, but in most people’s minds a fly is a fly, period. The species most people automatically think of are the house flies, blow flies, and bottle flies. Our disdain for these pests is understandable because they are known transmitters of human diseases, but non-pest black soldier flies (Hermetia illucens) are different in several ways. The most important difference is that BSF are not vectors of human pathogens. Black soldier flies rarely go into human habitats or land on people, and the adult black soldier fly doesn’t even eat during it’s short lifespan. Now that I’ve gotten that out of the way, on to the mythbusting. :)

Swarms of black soldier flies = myth

I’m convinced that most people imagine a swarm of black soldier flies hovering around a BSF composting unit such as a BioPod. They would be wrong. I’ve been culturing black soldier fly larvae for one and a half years and the greatest number of winged adults I’ve seen at any one time is less than 10. Most of the time when I check my BioPod there are no flies near it. I don’t think I’ve ever seen one before noon (apparently they sleep in), and you don’t see them when the sun is low or at night.

In case I haven’t made my point, BSF adults (winged stage) are relatively rare. One reason is that the adults only live a few days, just long enough to breed and lay eggs, and then they die. Contrast this with house flies that live 30 days or more. In the short period that BSF spend as adult flies there just isn’t enough time for big social gatherings such as swarms.

Black soldier flies pester people = myth

Black soldier flies can’t bite or sting and they don’t eat so they have no interest in people. As mentioned above you probably won’t see many BSF adults and if you do they will usually ignore you. On the rare occasions when a BSF adult lands on me it’s most often when I’ve been handling larvae and I have their scent on my hands. They land then because the subtle scent of BSF larvae is a powerful attractant to BSF females and if one lands on me I always pause to admire this beautiful beneficial insect. To be honest, I usually refer to any BSF adults I see around the BioPod as “the girls”, because males are not attracted to the unit. All of the BSF near the BioPod will be females looking for a good site to lay eggs.

BSF larvae are pests in honey bee hives = myth

I believe the BSF page at Wikipedia was the main source of this myth. Earlier versions of Wikipedia’s page about BSF stated that “The larvae can be destructive pests in honeybee hives”. There was no reference cited (that I could see) for that statement. I’ve searched the web for evidence that this is a true statement but I have found none. Perhaps the error happened because of reports that BSF larvae have been found in abandoned beehives. That is very likely since no self respecting BSF larvae would let perfectly good beehive waste go to…. waste! This is a very different scenario than the larvae being pests.

Today I spoke with Ellen Hudson, a previous head of the Apalachee Beekeepers Association, and she was unaware of any issues caused by BSF. If there really was an issue with beehives it would surely be a concern in this region where tupelo honey is a big business and BSF are plentiful.


To be continued…              solider

Black soldier fly composting in the frigid north

Aug 162008
 

frigid north

Actually, this post applies to any region that has seasonal temperatures below that which support BSF mating. This encompasses the entire continental U.S. except for a few extreme southern areas.

Black soldier flies (Hermetia illucens) are common in tropical and subtropical regions, but their range extends into many 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 its own heat

Maintaining a BSF unit in cold weather without heating it is possible because the churning action and digestion of the black soldier fly grubs 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. You can think of it like a diesel engine, if it gets cold then it’s hard to get it started again.

If the larvae are exposed to freezing temperatures they will die. Also, any insulation on top of the colony needs to have an air gap between it and the BioPod.

Maintaining a BSF colony during extended periods of sub-freezing weather will probably be a challenge for a novice, but it’s worth tying because at worst you’ll learn more about this fascinating creature. If you aren’t up to the challenge just yet then you can enjoy BSF culturing up to the point where the weather in your area makes it difficult and then resume in the spring. If you can store some or all of the compost through the winter it should make attracting the BSF easier in the spring.

Process more food scraps, harvest less larvae

The time it takes BSF larvae to mature increases in cold weather from the usual few weeks to a period of up to several months. I’ve maintained BSF larvae in the juvenile stage (light color, actively feeding) for five months through winter keeping the unit outdoors with some insulation. The same individual larvae will eat all winter which enables you to continue bio-composting without the need to replenish the colony with visiting females. However, since reproduction doesn’t happen at this time you must stop harvesting larvae if you wish to continue processing waste through the cold season.

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

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 :) ).

Mike made a comment below reminding me of a presentation by ESR about BSF culturing in winter. Here is a link to that article: http://www.esrla.com/winter/frame.htm

solider

Black Soldier Fly cultivation – “nuts and bolts”

Aug 062008
 

nuts and bolts 4

The purpose of this post is to feature a blog that is valuable to anyone researching black soldier flies (Hermetia illucens). It’s called BioSystems Design 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.

A US company founded by Grant Canary in Portland, Oregon, 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 La 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.

From the BioSystems Design blog:

A Primer on Black Soldier Fly

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.

solider

Take the black soldier fly challenge

Jul 292008
 

I believe black soldier fly larvae (Hermetia illucens) 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.
  • BSF grubs can be processed to create bio-fuels and other valuable products

The challenge

I’m making the claim that bio-conversion of putrescent waste with BSF larvae is the best way to deal with the constant stream of rotting waste that goes into landfill. The challenge is simple, state any significant problem that might be caused by using BSF to convert our organic garbage into nutritious animal feed or high quality products for industry such as bio-fuels.

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?

The cutest black soldier fly researcher EVER!

Jul 082008
 

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

YouTube Preview Image

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.

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