In this article, we look at the life cycle of the black soldier fly, one of the most important insects for composting and as a feeder.
Nowadays, constructing a black soldier fly farm is quite popular.
These insects are edible and provide excellent amounts of protein, plus they are ideal for organic waste management.
It might seem easy to breed these insects, but it is not; especially when you are unaware of the factors that affect the health and growth of the larva.
This article will help you understand the life cycle of these insects and the factors that affect them.
What Are Black Soldier Flies?
Black soldier flies (Hermetia Illucens) are a tiny wasp-like insect species found buzzing near decaying matter. They get their name from the pitch-black bodies.
These insects might look similar to wasps, but there are many notable differences. For example, these flies do not possess stingers. Also, they have two wings, and wasps have four.
You can spot these insects in various South American, Asian, European, and African regions.
The black soldier fly larvae are beneficial, as they help in food waste bioconversion.
They are also an excellent source of protein and can be used as animal feed for poultry. Also, these are edible insects and contain minerals and various essential amino acids.
Life Cycle of Black Soldier Flies
Like most insects, there are four life cycle stages of the black soldier fly: eggs, larvae, pupae, and adult flies. Let us take a look at all these stages in detail:
After mating, the female flies search for an ideal spot to lay the eggs. She carefully picks an area with abundant food sources, as these insects eat a lot in the larval stage.
An average female adult fly lays between 500 and 900 eggs.
Usually, the eggs hatch within four days. However, the time can differ according to factors like temperature, season, and region.
The larva needs to consume food constantly, as larval development significantly depends on the food they consume during this stage.
These insects have a humongous appetite and will consume almost anything they get.
They mostly rely on discarded grains, food waste, and manure to get big enough to start pupating.
You will be fascinated to know that these larvae can grow almost 1,000 times their initial size.
They continue this feeding spree for almost 18 days before starting the pupation process.
This is why they are often farmed by people, especially poultry owners.
You must note that these tiny larvae can molt multiple times to accommodate rapid larval growth.
Once the feeding larva attains a specific size, it stops feeding and prepares to begin pupation.
To do so, they leave the feeding area and move to a dry and secure location.
Here the larva starts building a protective surface around the body, which takes a pupal shape.
It takes around two weeks for adults to emerge from the pupa.
Throughout the entire adult stage, black soldier flies do not consume food; they rely on the fat reserves built by the larvae meal.
Fascinatingly, these adults do not live for long. An average healthy black soldier fly can live for 7-9 days.
During this time, they focus on mating, finding nesting spots, and laying eggs.
Factors Affecting the Life Cycle and Growth of Black Soldier Flies
Now that you know the life cycle of insects, it is time to uncover the factors that affect them.
Mentioned below are the key factors that alter or affect the black soldier fly’s life cycle:
A specific wavelength of sunlight is required for proper mating, survival, growth, and overall development.
If you have a black soldier fly farm, install artificial light and maintain a certain intensity of light.
Doing so can help increase the population outside of their natural habitat.
You must know that oviposition and mating get better with the presence of quartz iodide lamps.
The moisture content of the waste plays a vital role in the survival and growth of the larva.
Lack of moisture in the items can make them hard to process, and excessive moisture can obstruct the decomposition rate.
Hence, it is crucial to maintain a proper moisture content to tackle these problems.
Ideally, 40% to 60% of the moisture content is needed to boost the larvae’s survival rate. However, this figure is only true for larvae fed with poultry manure
Humidity & Temperatures
Black soldier flies can tolerate temperatures ranging from 15-47°C. However, some previous studies reveal that these insects are extremely sensitive.
The entire life cycle is affected by the rise and fall in temperature. For example, it takes longer for eggs to hatch at lower temperatures.
The larval growth is also affected by the humidity and temperature of the area.
If you want to open a black soldier fly farm, you must know that temperature and humidity can affect the longevity of adult black soldier flies.
Adults live longer at intermediate temperatures as they face problems surviving in high temperatures.
It is ideal to breed these insects at 27 °C in 60% humidity. Doing so creates the perfect egg-laying conditions for the females.
The pH value is a crucial factor that influences the life span of these insects. For ideal larval development, pH should be above 6.
Other studies also state that larval bodies increase at 4 or 2 pH levels. Also, the larvae residing on alkaline substrates can live and grow at pH values ranging from 8 to 8.5.
How Long Do Black Soldier Flies Live?
Black soldier flies do not live long as adults. These adults focus on mating and laying eggs. Average, healthy black soldier flies can live for around nine days.
These insects can survive for a total of 45 days in all four life stages (4 days as eggs, 18 days as larvae, 14 days as pupae, and nine days as adults).
Black soldier flies are excellent tools for organic waste control and handling various environmental issues.
These insects are loaded with proteins, amino acids, and fatty acids. These are edible insects and can also be used as poultry feed for chickens.
If you want to build a black soldier fly farm, you must understand its life cycle and the various factors that affect its lifespan.
Keep a close eye on factors like moisture, sunlight, temperature, humidity, and pH to have a healthy population of black soldier fly larvae on your farm.
Use the tips and tricks mentioned in the article to maintain the ideal sunlight, temperature, and humidity on your farm.
Thank you for taking the time to read the article.
Frequently Asked Questions
How long does black soldier fly live?
The black soldier fly has four life cycle stages: eggs, larvae, pupae, and adult flies. The female lays between 500 and 900 eggs in an area with abundant food sources.
The larvae have a huge appetite and consume discarded grains, food waste, and manure.
They can grow almost 1,000 times their initial size before starting the pupation process, which takes around two weeks for adults to emerge from the pupa.
The adults do not consume food and live for only 7-9 days, focusing on mating, finding nesting spots, and laying eggs.
These flies are often farmed by people, especially poultry owners, as they break down organic material into manure and animal remains.
How many times does a black soldier fly lay eggs?
The black soldier fly is used for reproduction in cages, with each female laying around 700-900 eggs at once.
The eggs hatch into larvae, which are sorted and prepared for growth stalls.
Effective reproduction is a focus, with multiple generations of fly cages and optimized egg harvesting. The black soldier fly has a lifespan of around 10 days.
Where do black soldier fly lay eggs?
The black soldier fly lays eggs near decaying organic material instead of directly on it, and the larvae consume it upon hatching. The adults only fly during the warm months, from April to October.
How long does it take black soldier fly larvae to fly?
The black soldier fly lays 200-600 eggs, which hatch after 4 days.
The larvae grow to 25mm in length in 10-28 days before entering the pupa stage and transforming into adult flies.
This lifecycle is shorter than that of other insects popular in the farming industry.
For those wanting to start a black soldier fly farm, understanding their lifecycle and the factors that help them grow is extremely important.
Over the years, many of our readers have taken an interest in this activity, and here are a few emails from them expressing their questions and doubts.
Letter 1 – Ovipositing Soldier Fly
Subject: Bug identification Location: Huntsville, Ontario, Canada June 14, 2016 3:39 pm Hello, I noticed this interesting horsefly-like bug laying these green eggs on our car mirror in late spring (June 14th) in Huntsville Ontario. I was hoping you could help identify? It seems like a horse fly, but the eggs are green rather than milky white as many sites have suggested they would be. I wondered if it was a bee at first? I appreciate any help. Thanks! Signature: Matt Dear Matt, We believe we have correctly identified your ovipositing Soldier Fly as either Stratiomys adelpha or Stratiomys discalis based on images posted to BugGuide. According to BugGuide: “S. adelpha and S. discalis are very similar and may turn out to be the same species. The taxonomy of the Nearctic Stratiomys is a mess. There are a few easily distinguished species, but several spp. are defined based on coloration which is variable. The male genitalia have never been examined carefully, and they could be helpful. –N.E. Woodley, pers. comm.”
Letter 2 – Wingless Soldier Fly from Australia
Subject: Found a bug I’ve never seen before Geographic location of the bug: Central Victoria, Australia Date: 04/28/2018 Time: 05:47 AM EDT Your letter to the bugman: Dear bug man, found this sick looking bug when out camping. I’ve never seen anything like it before How you want your letter signed: From brett Dear Brett, The first time we received an image of this species of flightless Female Soldier Fly, Boreoides subulatus, we did not know if we were looking at a mutilated individual that was missing its wings. The species is pictured on iNaturalist and on Atlas of Living Australia, and according to the Museums Victoria site: “Female Wingless Soldier Flies are seen on walls and fences, laying masses of long white eggs. Larvae live in damp soil or rotting vegetation, especially in or near compost.”