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Development of Black Soldier Fly, Hermetia illucens (Diptera: Stratiomyidae) in Selected Organic Market Waste Fractions in Accra, Ghana
Aims: To assess the effect of organic waste and their formulations on the development of the black soldier fly larvae.
Study Design: The experiment used one time feeding (lump feeding) of feedstocks obtained from organic market waste fractions and their combinations. The arrangement of composting containers followed a Randomized Complete Block Design (RCBD), replicated three times.
Place and Duration of Study: The study took 3 months and was conducted at the BSF laboratory of the Soil and Environmental Science Research Centre, Biotechnology and Nuclear Agriculture Research Institute of the Ghana Atomic Energy Commission in Accra, Ghana, West Africa.
Methodology: Two hundred and forty (240) hand counted 5-day old BSF larvae were inoculated onto 2 kg each of organic market waste fractions and their combinations in 60 L plastic containers covered with a mesh. Equal quantities of the above feedstock without larvae served as control. The arrangement of the containers followed a Randomized Complete Block Design (RCBD), replicated three times. Moisture content, larval growth parameters, temperature, relative humidity, prepupal development were recorded.
Results: Whiles moisture contents of most of the feedstock decreased gradually over the trial period, that of fruit waste only, fruit waste + corn husk and fruit waste + vegetable waste increased with time and was higher at the end of the trial than at the beginning. Composting temperature in all the feed stocks never reached the thermophilic stage and was between 29 – 38°C. The lowest temperature of 28.88°C was recorded in the mixture of vegetable waste and fruit waste whiles the highest, 37.55°C was recorded in the mixture of corn husk and uncooked food waste compost. Composting humidity ranged between 59 and 87% with significant differences being observed across treatments on days 0, 10, 15, 20 and 25. Larvae reared on a mixture of all the feedstock was significantly the heaviest (176.66 mg). Significant differences were observed in larval length and those fed with a mixture of fruit waste and uncooked food waste were the longest (17.66 mm). A highly significant number of eclosed adults, number of females and the number of egg clutches were observed among treatments.
Conclusions: Vegetable waste only, fruit waste only and a combination of vegetable waste + uncooked food waste; fruit waste +uncooked food waste; and a combination of all the wastes were the most preferred organic waste as they produced the optimum larval characteristics. The composting bins should be fitted with an outlet for leachates from the compost to drain out to avoid increase in compost moisture which will create anaerobic conditions that might delay compost maturity.