How to Breed BSFL
Insects at all life stages are rich sources of protein, fat, and many other important nutrients, and can be eaten by humans or used as feed for human food animals like fish, poultry, rabbits, and swine. Fly larvae are particularly recommended for this purpose because they contain a high amount of animal protein.
In Fly larvae, the black soldier fly (BFS), Hermetia illucens, has tremendous potential and capable of digesting almost any organic matter and converting it into insect biomass. The larvae can be fed live to fish or poultry, processed into feed comparable to fishmeal or soy meal, or even used to generate Biofuel. Thus, the fly not only eliminates waste, but also can improve the sustainability of livestock production.
Around the world, black soldier fly farms and composting facilities are being established to process waste into animal feed, with economic and environmental benefits. In this article we will review the breeding technique for BFS and different environmental factors affecting the BFS production.
BFSL Breeding Structure and Design
The preferred product to use is a BioPod Plus Auto-Harvesting Grub Composter. The design of the bin consists of:
- One body, One main lid kit, One inner convenience lid, One drainage plate, One drainage pad, One harvest bucket, One external drainage assembly.
- The main body dimensions are 26 1/2" long by 15 1/2" wide.
16" tall and 9" diameter of circular top.
Ventilation portal Drainage Plate is 27 cm long x 44 cm wide x 0.3 cm thick.
- Pair of angled 40” migration ramps that allow black soldier fly larvae to crawl naturally into the Harvest slit.
- Inner edge of 2” wide ramps have a raised lip to guide larvae into the harvest slit, which acts as an entry chute to the harvest bucket below.
- Weather and mold-resistant.
- Covered harvest bucket collects black soldier fly larvae, naturally separating mature and maturing larvae.
- The bucket has a drip channel that diverts condensation and excess liquid away from the organic matter, and an air slot for ventilation.
In terms of functional capacity, this particular bin can hold a maximum of 2.2 kg/5lbs per day. The bioconversion is projected at 15-20% of food waste into BSFL and a 3-5% bioconversion of scraps into larvae residue.
BSF Life Cycle
BSF have quick life span, consists of almost 5-8 days. After becoming adults, BSF female fly quickly finds its Male mate. Mating occurs in mid air. After mating the female does not waste any time to lay 500+ eggs in a dry environment near edges or crevices of decaying organic matter.
After these eggs are laid, they remain in this stage for approximately 4.5 days or 105 hours. Once the eggs hatch, the larvae find whatever waste they can and immediately start to consume it. Two weeks later, the larvae have reached full maturity given their environmental conditions are favorable.
It may take up to six months for larvae to reach maturity due to black soldier flies’ ability to extend their life cycle in hostile circumstances. The larvae can be up to roughly 27 mm in length and 6 mm in width. They have a pale white color with a small black head containing their mouthparts.
Following the maturity of the BSFL, pupae stages begin where the sixth instars (final molting phase in Hermetia illucens) larvae remove themselves from their feeding sites in search of a dry, sheltered environment.
Once this occurs, pupation commences. As a result, the exoskeleton darkens in pigmentation and a pupa develops inside of the exoskeleton. Pupation takes another two weeks before an adult emerges from the pupae case. Then, the adult emerges to reproduce again and the cycle repeats.
Optimum Environmental Conditions for BSF Breeding
Black soldier flies are extremely sensitive to their environments. Considering black soldier flies are an equatorial and generally a warm-season temperate species, their lifespan is dictated by how warm their environment is. Studies found that a temperature of 27C° for both males and females was most favorable during larval, prepupal, pupal, and adult stage. Once temperatures hit a higher threshold of 30-36 C° , black soldier fly development is acutely inhibited.
Black soldier flies, as previously stated, are extremely temperature sensitive. With this, they are also highly receptive to humidity. Low humidity levels results in water loss through the egg membrane. Studies found that 25% RH (relative humidity) causes higher rates of desiccation and higher mortality rates on black soldier fly eggs. At 70% RH, adults lived 2-3d longer that adult black soldier flies subjected to lower RH levels. A relative humidity of 30-90% promotes mating and oviposition when eggs and larvae are reared in a 27C° environment.
Another aspect to be considered is a light source, considering black soldier flies do not mate in the winter months. Naturally, black soldier flies require direct sunlight to encourage mating. Thus, operations indoors require supplemented artificial lighting. Under natural direct sunlight, 85% of mating activity happened in the morning with 110 µmol m2s -1. A 500-watt, 135 µmol m2s -1 light intensity quartz-iodine lamp stimulates mating and oviposition at rates and times comparable to those under natural sunlight. Studies found that that, insects couldn’t see wavelengths past 700 nm; therefore, wavelengths between 350-450 nm produced by a rare earth lamp should not be used, as they do not produce mating behaviors. A higher wavelength of 450-700 nm is recommended to produce mating behaviors out of black soldier fly adults.
As adults, BSF cannot feed; however, automatic or frequent water misting provides an adequate amount of water to the adults. The mists form droplets, which are then taken up by the adults. The adults’ main energy source is the remaining fat stored from their larval stages. Larvae have a much wider range and greater demands for sustenance. BSF require a certain level of moisture in the organic matter they are consuming.