What Do Black Soldier Fly Larvae Eat?

In this article, let us look at what you can feed the feeders: what do black soldier fly larvae eat? We cover various types of organic matter that you can feed your BSFLs.

Black soldier fly larvae are a great way of turning food scraps and other agricultural waste into high-quality compost. 

The insects, as a by-product, can be further turned into chicken feed or poultry food. 

Being a great food source and efficient compost producer, they are largely used in food waste management and the animal food industry to break down organic wastes. 

They are also certified for human consumption as a source of protein –  though they’re yet to be viewed as a common food source by the general public. 

Let’s take a look at how the larvae are reared, fed, and used for this purpose. 

What Do Black Soldier Flies Eat in Nature? 

Black soldier flies help with decomposition and, hence, thrive on decaying organic matter. 

This includes all types of kitchen scraps, dying vegetation, fruits, vegetables, manure, and even animal carcasses. 

In fact, they help with the decomposition of some particularly difficult agricultural waste materials, such as rice straws. 

Rice straws have high lignocellulosic matter but are too low quality for feeding livestock. BSFL (black soldier fly larvae) helps to valorize these into compost. 

Due to their ability to eat almost anything, it’s easy to rear black soldier flies. 

There are many low-cost CORS (Conversion of Organic Refuse by Saprophages) systems that utilize BSFL for producing compost. 

Industrial-level BSFL-rearing facilities also exist, but these are governed by various laws regarding treatment and quality standards. 

Best Nutritional Content For BSFL 

Despite the ability of BSFL to break down any organic matter, what they feed on defines how nutritious the larvae are. 

This is especially important if one plans on using the larvae later on as fish or livestock feed.

This is because, if fed on toxic waste or exposed to biohazards and heavy metals, the larvae can retain these substances within their system. 

When consumed by livestock, the toxins get introduced into the food chain – resulting in a hard-to-break cycle. 

Currently, Hermetia illucens, or BSFL, is one of the seven recognized insect species that can be used for compost treatment and animal food. 

Some Union laws for the best nutritional content to be fed to BSFL are:

• BSFL should only be fed contents that are non-animal in nature of origin. This means they can mainly feed on vegetative matter. 
• Some animal products such as honey, eggs, fishmeal, and gelatin are allowed – but only leftovers from human consumption (as these have been treated and blacked). Animal manure, human waste, or flesh is not on the list. This is to prevent the introduction of potential pathogens in the BSFL. 
• The feed given to them should contain at least 34% crude protein and 32% fat. 

When composting locally, farmers do not follow these rules. Chicken manure and fish intestines are very common BSFL feeds within the US. 

What to Feed Your BSFLs When Raising Them as Feeders

If you’re raiding BSFL by yourself, providing them with a varied diet is paramount. 

A good diet also helps with quick development and a more efficient breakdown rate. 

Besides, it creates healthy, nutritious larvae for your livestock to feed on. Here’s what you can feed them:

Food waste (Leftovers)

Any leftover food, both cooked and uncooked, is a good food source for BSFL. 

Human-grade food is also free from pathogens and potential contaminants, which makes it ideal for BSFL to feed on. 

It will eliminate any worry on your end about further affecting your livestock. 

Rotten fruits and vegetables

Rotten fruits and vegetables are a close second addition to the BSFL compost pile. 

Generally, if something starts decaying, it means there is significant bacterial growth, – and it’s best to provide the food to the BSFL before decomposition sets in. 

However, they can still consume decaying fruits. 

In fact, you also need to monitor your compost pile to ensure that the BSFL is able to decompose the food added every day before you add new amounts. 

BSFL compost does not smell – so if you do smell decay, it means you need to reduce the amount of food added every day. Or add more BSFL. 

Corn, soybeans, and other waste

Corn and soybeans are high in fat content and great food sources for the BSFL to break down and absorb. 

In the wild, BSFL tends to colonize these harder foods (and fruit rinds) naturally since they’re hard and form effective ovipositor traps. 

In other news, BSFL can actually fully replace any soybean-based diet fed to chickens. 

Fish waste

Fish waste can be a potential feeding item for BSFL – though it’s usually suggested to give them fish feed instead. 

And especially the ones used for non-salmonid species. The only downside to using fish waste is that it can introduce potential pathogens – if your fish was carrying them. 

Usually, farmers feed them fish intestines. You can also add whole fish since BSFL can break down bones.

Poultry manure

Chicken feed and poultry manure can be used if you are rearing BSFL locally. Industries do not use any form of manure due to pathogen introduction. 

We’ve discussed how to mix manure next. 

Animal manure

BSF naturally lays eggs in animal manure since it provides a rich substrate for the larvae to feed on. 

In fact, it’s best to create a manure mixture that contains 40% swine manure mixed with dog food. 

Or you could consider 50% kitchen waste mixed with chicken manure and some coarse minerals or coffee grounds. 

Coffee grounds waste disposal

Coffee grounds help boost metabolism but should be used as a sprinkle rather than an actual item. 

BSFL can survive fully on coffee grounds for a few weeks – however, the grounds in themselves do not have enough nutritional value to produce high-quality larvae and pupa. 

Cashew fruit

When cashews are harvested, 90% of the fruit is thrown away – with only the nut being used. 

The cashew fruit is being increasingly used as BSFL feed by many farmers. 

It contains sugar, amino acids, and vitamin C and is an efficient way of reducing the waste from cashew harvesting. 

Do You Need to Give BSFL Water? 

BSFL needs a certain amount of moisture content to thrive. Too dry, and they can shrivel, whereas too much water content can drown them. 

You can use a lid on the compost pile to maintain the humidity, along with a sensor. 

BSFL do not need water separately, as there is enough water content in most organic matter for them to survive on. 

If the feed is too dry (or consists of low water content items such as bones), you can spray some water onto the surface. 

For manure, you can consider adding it as a paste rather than as it is. 

Frequently Asked Questions

Wrap Up 

The consumption rate of the larvae is incredible, and each one consumes multiple times its body weight every single day. 

It’s best to provide a balanced diet for optimal larval growth. 

Using them allows farms to become more sustainable by recycling their kitchen and animal waste. 

BSFL are even being shipped now, packed within bales of hay and food items from proper rearing industries. 

Since they survive in most climates (unless it’s extremely cold) – it’s no wonder they’re becoming a popular decomposer insect. 

Thank you for reading.