Assessment of Vegetable and Fruit Substrates as Potential Rearing Media for Hermetia illucens (Diptera: Stratiomyidae) Larvae

Abstract

Hermetia illucens (L.) (Diptera: Stratiomyidae) is able to consume a wide range of organic matter and is of particular interest for waste management. The nutritional value of preimaginal stages, in particular the protein content, makes this species a valid candidate for use as feed for other organisms. Vegetables and fruits are promising rearing substrates for insects produced for this purpose according to the EU regulation. In order to examine the effects of diets on insect performance and chemical composition, larvae were reared on the following substrates: 1) fruit (apple, pear, and orange); 2) vegetable (lettuce, green beans, and cabbage); and 3) mixed fruits and vegetables. High percentages of survival were observed on all diets, but there were differences among weights of larvae, pupae, and adults, with weights of larvae reared on mixed fruits and vegetables lower than on other diets. Pupae reared on the mixed diet were heaviest, and also morphometric measurements of adults were highest. Larvae reared on fruit diets had the highest fat content, comprising mostly saturated fatty acids; the highest content of essential n-3 fatty acids was found in vegetable reared larvae and that of n-6 in mixed reared larvae. Larvae reared on the mixed diet had the highest protein content. Calcium contents were high and moderate amounts of iron and zinc were found. H. illucens showed the capability to develop on vegetable and fruits diets displaying different nutrient profiles and biological performances. The best-performing rearing strategy should vary in relation to the final use of H. illucens.

Nutrient Recapture from Insect Farm Waste: Bioconversion with Hermetia illucens (L.) (Diptera: Stratiomyidae)

“…Survival results were in line or higher with other research where H. illucens was reared on artificial diets (e.g., Tomberlin et al, 2002) [51] or on organic substrates derived from different waste streams or byproducts [20,25,43,52]. The percentage of adult emergence was above 96% in all the experimental conditions, which is comparable to other studies on artificial diet or hen feed [50,53], but in contrast with other research conducted on diets of vegetal or animal origin [25,49,51]. Although the experimental substrates differed in chemical composition, no relevant differences were noticed in the larval development time, except on locust chopped waste where the larval growth was slower (up to seven days more).…”

“…We assessed how different rearing substrates influenced the larval growth in terms of final larval weight reached and development time, and the efficacy in waste reduction and bioconversion. As already observed, growth parameters for both larvae and adults were greatly influenced by the composition of feed substrates [22,25,41,49,50]. All experimental substrates allowed larval growth and emergence of H. illucens adults.…”

“…In particular, the weight observed in larvae grown on cricket waste was the highest and comparable, for example, to what was observed by Tschimer and Simon (2015) [19], rearing H. illucens on dried distiller and beet pulp. Many other studies showed lower weight of larvae when reared on waste streams, of either animal or vegetal origin [22,25,54]. Adult dimension (weight and length) strongly reflected the trend of the weight of the preimaginal instars.…”

Effects of microplastics and salinity on food waste processing by black soldier fly (Hermetia illucens) larvae

“…However, a higher pupation ratio and a lower substrate reduction rate were observed in the BSFL reared on food waste treated with PS and PE microplastics, compared to the control. Previous studies have been reported for the decomposition of diverse organic wastes including fruit and vegetable mixture and pig manure using BSFL, and the growth and development of BSFL differed depending on the substrates employed (Jucker et al 2017;Liu et al 2018;Meneguz et al 2018); this is not surprising given that various substrates including food waste have heterogenous traits in their composition (Hossain et al 2014). More studies are required to apply BSFL in processing of diverse types of food waste.…”

The Intestinal Microbiota of Hermetia illucens Larvae Is Affected by Diet and Shows a Diverse Composition in the Different Midgut Regions

“…However, the rate of waste recycling and the final value of the biomass obtained depend on the rearing strategy, in terms of feeding substrate composition, feed consumption rate, and environmental parameters (i.e., temperature, humidity, and photoperiod) (1). For this reason, many research efforts now focus on the characterization of nutrient and micronutrient content of BSF larvae in response to different rearing conditions and substrates, in order to optimize biomass yield and quality (1,(6)(7)(8)(9)(10).…”