What the heck is a Black Soldier Fly ( Hermetia illucens)

Hermetia illucens, or as they are more commonly known the Black Soldier Fly ( BSF for short), is a small black fly that is part of the Stratiomyidae family. Often mistaken for a wasp, the adult black soldier fly is approximately 5/8” long (16mm) and has two clear windows on their abdomen (that last section of their body). These little windows serve as a defense mechanism so that when light hits them it confuses birds and other predators. The adult fly also features blackish-blue metallic looking wings and big eyes with iridescence on them. (similar to dirty soap water or oil on the road makes that rainbow color when the light hits it if that gives you an idea)  Any of the above physical characteristics imply BSF, but where you find them is the real indicator.

Adult black soldier fly on white background
The adult black soldier fly is approximately 5/8″ long and features blackish-blue metallic looking wings.

The adult black solider fly is almost always found near a source of waste or decaying food. BSF is found in nearly all temperate or tropic places throughout the world; this includes much of SE Asia, Africa, Southern Europe and the American continents. If you can’t find them in your area; there is no need to worry. Soldier flies can be grown indoors with conditions that simulate their natural environment.

Like most insects, soldier flies start their lives as eggs. The larvae hatch from the eggs and feed on anything they can find. BSF larvae are a sturdy, cream colored grub that are usually covered with fine rows of hairs. After a period of time, the larvae stop feeding and begin to pupate. Once they stop moving and have turned completely black, the larvae are pupae and almost ready to become an adult. Soon after pupating, an adult fly emerges and begins mating to start the cycle over.

What do we feed them? Well the answer really is, take your pick! They can eat anything from a cheeseburger to animal manure. It really just depends what you have. The BSF larvae will be able to eat mostly anything as long as it has a good balance of proteins, fats and carbohydrates.

So, we know we can feed them anything, but what can we use these little bugs for? Well, we can use them to make food for chickens, fish, or even the pets in your house! We can use their fats to make bio-diesel, soaps and detergents. We can use whatever they don’t eat to make a amendment (fertilizer) for your garden. BSF will eat upwards of 60% of the food you give them (even more if you mash it up) meaning they take most of the waste you give them and bio-convert (or recycle) it. How? Well they eat it, that food turns into fats and proteins in their bodies which we can then harvest and feed to our animals or use for other useful items!

So now that we know what the heck BSF are and how to identify them; we can look at how we can grow them! Stay tuned for the next blog on that!


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5 thoughts on “What the heck is a Black Soldier Fly ( Hermetia illucens)”

  1. Concerned about the dead lumber in my home. Will the BSF find a way to lay eggs in my home causing an infestation? In regards to these critters I try to use larvae all up before THEIR metamorphosis.

  2. Hey Kelly

    BSF won’t generally lay in a home without a food source close by. It is very unlikely you will have BSF lay in your home, especially if you keep food wastes away from that lumber. Where you live will also have an impact as they really can’t survive in the wild through harsh summers or winters.

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