Rearing black soldier fly to supplement natural populations in waste composting systems

The black soldier fly, Hermetia illucens L. (Stratiomyidae; Diptera), is a common and widespread non-pest fly and an essential decomposer of organic material. Because of its ability to decompose wastes and return nutrients to the environment, it is considered to be a beneficial insect for manure management in confined animal facilities. Larvae are an excellent source of protein and other nutrients and are used for fish and animal feed. The development of efficient rearing systems for black soldier fly is important in order to provide a source of larvae to initiate soldier fly-based waste-recycling systems and to augment populations in existing systems. However information on black soldier fly rearing is relatively limited. The objectives of this study were: (1) to compare different media to identify those that result in optimal black soldier fly pupation rates and to track effects on subsequent adult emergence and oviposition, and (2) to determine the influence of moisture level in the pupation media on adult emergence. Three different pupation media were evaluated in the first experiment; compost, mulch and vermiculite. The results indicated that adult emergence rates were not significantly different among the different pupation media suggesting that all three media are suitable for pupation. A second experiment was done to evaluate the influence of moisture in mulch pupation media. In this experiment, the average number of adults emerging from the medium and high moisture level treatments were significantly greater than in the low moisture treatment. In addition, the overall total adult male and female emergence rates were also significantly higher in the high and medium moisture treatments compared to the low moisture treatment. These results suggest that moisture levels in pupation media should be maintained between 50-85% to achieve optimum adult emergence rates. However, about 10% of emergent adults in the high moisture level treatment had malformed wings. Therefore, moisture levels between 50-55% may be ideal to achieve optimum adult emergence without the occurrence of abnormal wing development. Successful adult mating and oviposition was achieved in commercially available BugDorm(TM) tents kept inside a greenhouse with supplemental lighting. These results demonstrate that successful black soldier fly mating and oviposition can occur in small cages with sufficient numbers of adults present and if they are kept in a greenhouse under the conditions described herein.