Black soldier fly, Hermetia illucens (Diptera: Stratiomyidae), is a voracious insect that feeds on organic materials. It consumes material twice as much as its own body weight in one day. This feature gives the BSF the potential to create an engineering wonder in reducing organic waste in underdeveloped or developing countries.
BSF is a useful bug that resembles a wasp in the length of 13-20 mm. It produces 3 generations per year. An adult female leaves 600-800 eggs at a time. After a 2-4 day incubation period, it forms larvae, which will last 21-24 days. During the last phase of the larva form, the pupa term, they cease to eat, empty their guts, their mouth parts change to an appendage that aids climbing, and they seek a humid sheltered area to pupate. This period lasts around 14 days. These times may vary according to nutritional and environmental conditions. During the adult term, they only drink water, mate, lay eggs and die after 4-8 days. If there is enough water, the adult form lasts longer. The adult mates after 2 days and lays eggs 2 days after mating. The female fly tends to place its eggs in the cracks near the food source. The eggs crack after 4 days. At 80% humidity and 26 °C, 88% of the eggs return to larvae. BSF does not approach humans; it is not a good flyer; and it is not found to be the carrier of any pathogenic microorganism.
BSF is a natural species originating from the southern USA, spread all over the tropical and subtropical regions of the world. BSF larvae are used for biological conversion of animal fertilizers, and controlling of animal feed and houseflies.
Figure 1. Black Soldier Fly Life Cycle
The use of BSF larvae in the conversion of wastes:
The developmental setting of BSF larvae varies from vegetable waste to animal corps (Sheppard et al., 2002). BSF is closely related to farming for several important reasons:
1. BSF helps reduce animal waste and converts it into high nutrient compost (Sheppard, 1983, Sheppard et al., 1994, and Erickson et al.2004). The pupa form, with 42% protein, 35% fat, has a conversion rate of 8% dry matter. That is, 100 grams of organic waste turned into 8 grams of larvae (Sheppard and Newton 2000). A 50% reduction in the amount of animal waste will result in a 42% and 26% reduction in the amount of less useful phosphorus and nitrogen. It reduces the negative effects of these substances on the environment. It removes adverse effects on the quality of drinking water that is contaminated with antibiotics and other veterinary drugs found in animal waste.
2. BSF larvae, due to their high protein and fat ratio, have a nutritional value that can be substituted for soy and fish flour mixture, which is used as chicken and fish feed. (Hale, 1973; Newton et al., 1977; Bondari and Sheppard, 1987).
3. BSF larvae prevent the development of housefly larvae in animal waste. They eat housefly larvae; and houseflies do not prefer to lay eggs where the BSF colony is because of the competition between them.
4. BSF decreases the smell of animal waste. It reduces the concentration of pathogenic microorganisms such as E.Coli and Salmonella in the waste, and creates a more hygienic environment by eating the helminth eggs (Sheppard, 1983; Sheppard and Newton, 2000; Newton et al., 2005; Liu et al., 2008; Eawag, www.Eawag.ch). It reduces the Lactobacillus activity to less than 1%. Although the PH of the medium containing the BSF larvae is relatively high, the amount of ammonia released when the fermentation takes place is reduced.
5. Because of its high fat content, BSF, when produced on a large scale, can be marketed as biodiesel.
6. BSF and worms living together is not found to be efficient; however the waste, undigested by BSF larvae but left with altered structure, can be used as compost and also is an excellent raw material for vermicompost.
7. It has been reported that when used as fish feed, BSF helps improve the immunity of fish and therefore contributes to the production of fish that are more resistant to diseases (Indonesia).
8. Since BSF lowers the cost of feed, it encourages small-scale live chicken breeding in rural areas.
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