The Black Soldier Fly

Curious about black soldier flies, and whether they're a benefit or a nuisance in your garden and compost?

I believe that most insects have a role to play in the garden. Getting to know each bug species that calls your garden home is so important if you want to understand the delicate balance of the ecosystem and to be able to make informed decisions without unintended consequences.

When it comes to black soldier flies and their larvae (BSFL), they are definitely garden friends!

Let's learn about what these critters do, and why you should have some in your garden.

Are Black Soldier Flies Harmful?

Not at all! Black soldier flies should be revered in any organic garden for their ability to break down food waste and cycle nutrients faster than almost any other creature.

Like worms on steroids, the larvae of black soldier flies can transmute almost any food scraps into rich black garden gold in just a few days.

Black Soldier Fly Advantages

For gardeners there are tremendous advantages to befriending and recruiting black soldier flies to help cycle garden nutrients.

Compost With Black Soldier Fly Larvae

One of the main reasons why BSFL are so beneficial to gardeners is because they are absolutely incredible composters.

Everyone is familiar with worms as great composters, breaking down organic matter into rich worm castings that plants love.

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Somewhat lesser-known and more effective are black soldier fly larvae, which can break down organic matter much faster than worms. Some estimates say up to 7x faster!

Black soldier fly larvae have voracious appetites and will chew through large pieces of produce in mere days. BSFL can eat twice their weight in food every day!

They also have incredibly powerful digestive enzymes, which can even break down thinks like bone and cartilage.

While worms works slowly in cooler temperatures, BSFL love the heat and can move faster and eat more in hot temperatures.

As incredibly efficient decomposers, BSFL are a valuable asset for any gardener looking to create healthy soil during the warm season!

Where I live in Arizona, that means worms make great macrodecomposers in winter, and black soldier fly larvae do the heavy lifting in summer.

BSFL Reduce Food Waste

But BSF larvae aren't just good for composting. They also play an important role in reducing food waste.

In fact, BSF larvae have been used in commercial settings too. There they break down food waste and create valuable byproducts like animal feed and biodiesel.

One super common approach people take is feeding their food scraps to BSFL, then feeding the BSFL to their chickens. This is a sweet way to close the nutrient loop and keep everything cycling 'round rather than going to waste.

Black Soldier Fly Disadvantages

While these are one of the most beneficial insects you can attract to your garden, they aren't completely without any disadvantages.

Difficulty Attracting

It can sometimes be difficult to attract black soldier flies to your compost. They're pretty selective about where they lay their eggs, and need a moist pile of decomposing organic matter that's warm enough to lay eggs in.

You'll need to create the right conditions if you want to attract BSF's to your compost pile.

If you're struggling to attract them or aren't seeing any soldier flies showing up, you can always purchase live BSF larvae and introduce them yourself once you've got your compost conditions dialed in.

Require Hot Temperatures

• Ideal temperature range: 80F - 86F (27C - 30C).
• Tolerable temperature range: 70F - 95F (21C - 35C).

Outside of these ranges, their activity diminishes substantially or they disappear altogether - moving onto warmer pastures.

This means that raising BSFL and getting their help with your compost process only work in hot climates of during the hot season.

If you don't experience these temperatures where you live, you may not be able to work with black soldier flies - though some folks do have success with them in greenhouses.

Require High Humidity

Black soldier flies need humid conditions along with the above-mentioned hot temps.

Relative humidity in the 60% - 80% range is ideal, which may be difficult to achieve in dry climates.

Where I live in the desert, this humidity range is unavailable naturally for most of the year, however black soldier flies thrive in compost bins I keep almost completely enclosed and well-watered.

I've observed that black soldier flies do not seem to tolerate my less-enclosed compost piles and prefer the increased moisture in my enclosed bins.

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The more dry your climate, the more you'll want to enclose your compost or BSFL bins in order to keep the moisture level up, and the more often you should water.

Take Some Getting Used To

Some people also find black soldier flies to be a bit scary, as they're easily confused for wasps until you learn to recognize them. With time, you can easily tell them apart.

Black soldier fly larvae can be a little off-putting to folks who aren't used to watching larvae devour food scraps.

Learning to love decomposition is a necessary piece of gardening, though, so if you're not an insect lover you might have success with slowly exposing yourself to them more and more over time (exposure therapy) and learning what you can about them to help overcome any fear.

What Conditions Do Black Soldier Flies Thrive In?

Soldier flies absolutely love the heat. I often notice them show up in my compost bin once daytime temps exceeds 80F (26.6C), which is about the temperature they breed at. In warm conditions where worms often slow down, black soldier fly larvae take over macrodecomposition in compost piles.

If you rely on worms during the cool season to help with your compost, black soldier fly larva, will make the perfect companion for the warmer half of the year if you're in a hot climate.

FAQs

Do Black Soldier Flies Bite?

Soldier flies don't bite or sting, and they don't spread any diseases to people. They're completely harmless to humans and pets.

They also don't harm your garden, nor do they caused any damage to plants. In fact, they don't even eat!

Rather, they'll lend a hand and help your garden to thrive.

Are Black Soldier Flies Good or Bad?

Not only are black soldier flies harmless to humans and pets, but they also play an important role in composting and soil-building!

Final BSFL Thoughts...

With a little bit of effort, attracting these compost friends is definitely worth your while.

BSF larvae are incredibly beneficial for composting and soil-building, and they are completely harmless to humans and pets.

Remember you can always buy the larvae live and introduce them if you're not seeing any show up on their own. Just make sure it's during the warm season and temps are 80F (26.6C)+ so that they breed and multiply in your compost.

Next time you see a black soldier fly in your garden, take a sec to appreciate all their hard work! They are busy keeping your soil healthy and turning food scraps into pure gold.