How does insect farming work?
An entomology technician inspects larvae in an Entocycle Growth Unit. Credit: Entocycle
Introduction
Insect farming is the process of raising insects for animal feed, pet food or other uses such as fertiliser and bio-based materials. It’s gaining popularity due to its environmental benefits, high protein yield, and efficiency compared to traditional livestock farming.
Commonly farmed insects include mealworms, crickets, and superworms; however, this guide focuses on the most widely farmed insect species worldwide – the black soldier fly (Hermetia illucens). Due to their high feed conversion ratio, rapid life cycle, and ability to efficiently convert a diverse range of organic waste into protein, black soldier fly larvae (BSFL) have become the preferred choice for large-scale insect protein production, with the sector projected to reach £4bn by 2033.
The black soldier fly farming process. Credit: Entocycle
The black soldier fly (BSF) production process
Commercial-scale BSF farming demands careful attention to various production stages to ensure efficiency and maximise yields. These stages reflect the fly’s natural life cycle and should support its biology and natural behaviours. This guide covers six key process areas of BSF production.
1. Feed Preparation
Feed preparation is essential for optimising BSFL growth and maximising conversion efficiency. BSF larvae can consume a variety of organic waste materials, and in principle, any form of organic matter can be used, subject to availability, cost, and regulatory restrictions. In the UK, currently permitted waste streams include brewers’ grains, dairy by-products, and vegetable by-products, while in other parts of the world, the allowable inputs are broader, with household food waste and animal manure often used as a substrate.
Despite BSF larvae's wide-ranging appetite, proper feedstock selection and preparation significantly influence their growth rate, yield, and nutritional composition.
Depending on the feedstock obtained, contaminants may need to be sorted and removed from the waste, and the feedstock may be treated using heat or fermentation to eliminate any pathogens that could be present and pose a risk to the larvae.
The larvae prefer fine to medium-sized particles to digest the material and enhance nutrient absorption. Therefore, the feedstock may need to be chopped or macerated to achieve the correct consistency. To ensure digestibility, the moisture content of the feedstock should be approximately 70%, so water may need to be added or, in some cases, evaporated to reach this level.
2. Larvae Dosing
Once the feed is prepared, it is then distributed evenly into crates. Neonates or 5-day-old larvae are then properly dosed onto the substrate contained within each crate to ensure even distribution and optimal growth.
Different approaches to dosing the larvae exist in the insect industry.
A conventional method involves operators counting a small sample, determining the average weight per neonate, and then using that data to roughly estimate larger populations by weighing. However, weighing can introduce errors due to variations in moisture content and individual larval weight differences. Inefficiencies in dosing and inconsistencies in larval populations can significantly affect feed conversion ratios (FCR)—a critical metric that determines the financial viability of a farm. Inaccurate estimates can lead to poor feed distribution, wasted resources, and potentially lost profits for operators.
A more contemporary method involves counting the number of neonates using an optical dosing machine equipped with a line-scan camera. Entocycle’s Entosight Neo employs machine vision technology to automate the counting and dosing of neonates into crates at a rate of 3000 per second. By tackling one of the most overlooked variables at the beginning of the production process, optical dosing technology can help unlock new levels of efficiency throughout the entire production system.
Entocycle’s industrial-scale facility design shows the distinct areas for Production, Breeding and Nursery stock. Credit: Entocycle
3. Larvae Growth
Once the crates have been accurately dosed to ensure an optimal feed level for the larvae, they are transported to the facility’s Larvae Growth area. The larval growth stage is where the majority of biomass conversion takes place, with larvae feeding voraciously and swiftly gaining weight. BSFL will gain approximately 5,000 times its body weight during this phase.
BSF larvae favour dark conditions, so keeping the growing trays covered or enclosed can enhance feeding activity. Climate control is crucial here, with a temperature of 27–32°C ideal for rapid growth and efficient digestion. An HVAC system provides consistent airflow and prevents the buildup of ammonia and other gases.
Depending on the type of facility, the Larvae Growth area may have several units dedicated to breeding and production and a nursery unit for housing neonates to 5-day-old larvae.
Typically, after 12 to 14 days, the larvae attain their maximum biomass and protein content, making them ready for harvest and processing into feed or pet food ingredients. Approximately 2% of the population is separated and permitted to enter the prepupal stage to become ‘Breeding Stock’ and repeat the breeding cycle.
4. Pupae Development
BSF larvae enter the prepupal stage after consuming sufficient nutrients, signalling their readiness to transform into adult flies. The pupation area should remain completely dark, mimicking natural conditions to encourage successful metamorphosis. Pupation lasts approximately 7 to 10 days, and once fully developed, adult flies emerge, prepared for the breeding cycle and ready to enter the Fly Rooms in search of a mate.
5. Breeding (Fly Stage)
Successful BSF reproduction is essential for ensuring a consistent supply of larvae for commercial operations. Once the adult flies emerge, they are moved to a designated area for breeding, where individual rooms or cages are populated with the flies to facilitate mating.
BSF mating necessitates bright light (natural sunlight or artificial UV light at 10,000–20,000 lux) and a room temperature of 27–30°C. The design of the fly room also plays a crucial role in promoting mating and consistent egg production. Key factors include optimising the fly density in each room to ensure sufficient surface area for the flies to rest, as well as strategically positioning egg traps to encourage females to lay their eggs. It may seem obvious, but happy, un-stressed flies produce more eggs, and by fine-tuning these factors, a facility can maximise reproductive output, thus ensuring a steady supply of neonates for the production process.
Egg traps are then collected and moved to another environmentally controlled location, typically called a hatchery, where the eggs hatch and the production cycle begins anew.
An entomologist holding a full egg trap. Credit: Entocycle
6. Product Processing
Once the larvae (from the production stock) have reached their maximum protein content, they are separated from the frass, which is primarily composed of insect excrement, and harvested for processing into feed or pet food ingredients. The larvae are cleaned to eliminate any leftover feed or debris and then swiftly terminated to minimise any potential suffering.
Depending on the extent of the post-processing facilities on site, larvae may be processed and packaged whole, then frozen for offtake or dried to reduce moisture content for long-term storage. Further processing may involve milling the dried larvae into a fine powder and extracting the oils or fats from them.
Whole BSFL is most commonly used in pet food, while protein meal and separated fats are frequently used in animal feed or aquafeed. The frass, rich in nitrogen and chitin, can be dried and packaged as an organic fertiliser to promote plant growth, subject to local regulations.
Whole frozen BSF larvae. Credit: Entocycle
Conclusion
Farming black soldier flies on a commercial scale demands careful management at every stage, from feed selection and preparation to product processing. Optimising these stages ensures high efficiency, maximum biomass yields, and profitable outputs. As the demand for low-carbon protein sources increases, BSF farming emerges as a promising and scalable solution for waste management and animal feed production.
By adhering to best practices in feed selection, environmental control, and processing techniques, commercial BSF farms can realise sustainable and profitable operations while contributing to a circular economy.
If you’re looking for expert guidance on planning, designing, and delivering commercial insect farms, get in touch with Entocycle. Our experienced team is here to provide comprehensive solutions to help you successfully establish and scale your BSF operation. Entocycle – your full-service build partner for commercial insect farms.