What Do Black Soldier Flies Eat?

Black soldier fly (Hermetia illucens) is a species known for their ability to consume and recycle a wide variety of organic (waste) materials, making them highly valuable for waste management and sustainability efforts. However, it’s their larvae—not the adult flies—that are responsible for this remarkable feeding behavior.

The Larval Diet

Black soldier fly larvae are voracious feeders and thrive on decomposing organic matter. Their diet includes:

Food Waste:

◦ Fruits, vegetables, and other kitchen scraps.

◦ Spoiled or leftover food that would otherwise go to landfills.

Agricultural Waste:

◦ Crop residues, plant material, and other byproducts of farming.

Brewery waste, including spent grains.

Manure:

◦ Animal manure, including that from poultry, cattle, and pigs. This ability makes them useful in agricultural systems for managing livestock waste.

Other Organic Materials:

◦ Rotting meat, fish, or dairy.

What Adults Eat

Adult black soldier flies do not eat solid food. Instead, they rely on the energy reserves accumulated during their larval stage. They may sip on water or nectar but do not contribute to waste recycling.

Why Their Diet Matters

The black soldier fly’s feeding habits have significant environmental and economic benefits:

• Waste Reduction: Their larvae can reduce organic waste volume by up to 70% (depends highly on the source material composition, recipe and growth environment).

• Sustainability: They convert low-value waste into high-value protein and compost (frass).

• Circular Economy: The larvae themselves can be harvested as a sustainable feed for livestock and aquaculture.

In summary, black soldier flies primarily consume organic waste, with their larvae being the true powerhouse of this process. Their ability to transform waste into valuable resources makes them a cornerstone of sustainable waste management practices, alternative protein source for farm animals and pets, but also for human food consumption as an ingredient.