WHAT ARE BLACK SOLDIER FLIES?



  • Pupae
  • Emerges
  • Mates
  • Lays
  • Egg incubates
  • Larvae Eats


Black Soldier Flies (BSF)

are clean, non-nuisance flies, high in protein that require minimal effort to raise. BSF have been tested and found to provide numerous ecological benefits. BSF are voracious eaters and can consume up to 10 times their body weight each day. In a BSF farm, a functional 1 square meter is estimated to process at least 40 kg of food per day! This becomes extraordinarily interesting when taken with their diet– organic food matter. Anything that humans eat, BSF will also eat. BSF preferred diet is fruit and vegetable waste. BSF also eat coffee grinds, bread, meat, and cheese but they cannot digest bones or leaves and other plant materials.

BSF are particularly interesting because while they consume organics, they do not eat rotten food. They cannot exist in an anaerobic (lacking in oxygen/rotten) environment. When faced with these conditions, BSF will try to leave from rotting food in search of a more oxygen friendly, dry environment. Studies have also shown that BSF also reduce the amount of dangerous diseases present in their food environment. When test food was injected with E. Coli and Salmonella, researchers found that BSF digestive enzymes helped clear out the contamination.

BSF are also high in lipid content, about 35%. In addition to converting waste into protein, this factor of BSF larvae also presents another interesting opportunity for developers. First, the lipids can be extracted from BSF and this produces a low cost biodiesel. Second, the residue is still useful as a high protein (70%) refined feed.

Life Cycle.

The total life of the BSF can be between 6-7 weeks. Eggs hatch in 2-4 days. Infant larvae are an off-white color, and darken as they age. When hatched, larvae begin and continue eating for 14-18 days. This time period is the key time period for production. As larvae develop into prepupae, their exterior becomes much harder and their color darkens to black. At this point, BSF prepupae instinctively leave the feeding area looking for a place to pupate. They will naturally self-harvest, climbing up a 30-45 degree ramp to separate from the colony.

The self-harvesting behavior of the prepupae is one of the key factors that makes them easy to rear. The benefits are two-fold. First, by separating out in a predictable pattern, BSF can be harvested with very little effort at the exact time they have reached prime viability. Second, because they pupate and mate away from the group, eggs are oviposited away from food sources– this eliminates them as a vector of disease. BSF will pupate and emerge as an adult, taking between 15-18 days to complete this process. Once BSF have emerged, the only purpose they serve is to mate. In fact, adult BSF do not have functioning mouthparts during their 5-8 day life, living on the fat produced as larvae and drinking water.

Ideal Living Conditions.

BSF are of great interest because of their tough design. BSF are sensitive to environmental conditions, food sources and light, which can affect their growth. However, unlike other insects, fish and animals, BSF will not die unless subject to extreme heat or cold. Variations in temperature from 15C to 50C will only change their growth patterns. Ideally, BSF develop best in temperatures between 30-40C, but will still achieve good growth from 25-45. Temperatures above 45 will quicken harvesting, as pre-mature larvae will exit the group in search of cooler temperatures. Low temperatures will lengthen the development phase. Larvae will become slow and lethargic. In the case of food scarcity, larvae can survive months with little to no food supply. A lack of food only lengthens their development time until they can consume enough organic material to pupate.