Food futurists accept that sustainability-minded humanity will increasingly incorporate insects as alternative protein. The most studied and easily reared species are not necessarily the most sustainable, acceptable, or delicious. Here, we review the literature on the black soldier fly, Hermetia illucens, which is capable of efficiently converting a wide variety of organic materials, from food waste to manure, into insect biomass. They can be grown and harvested without dedicated facilities and are not pestiferous. Their larvae are 42% crude protein and 29% fat, although they are higher in saturated fats than most insects. They do not concentrate pesticides or mycotoxins. They are already grown and recommended for use as animal feed, but with regional legal restrictions on how this is done. For commercial use in human foods, larvae could potentially be milled and converted into a textured protein with a strong flavor. Their biggest advantage over other insects is their ability to convert waste into food, generating value and closing nutrient loops as they reduce pollution and costs. This general advantage is also their greatest disadvantage, for the social stigmas and legal prohibitions against eating organisms that eat waste are added to extant taboos facing insect consumption.

Review of Black Soldier Fly (Hermetia illucens) as Animal Feed and Human Food

The black soldier fly (BSF; Hermetia illucens L; Diptera: Stratiomyidae) has been studied for its capability to convert organic waste to high quality protein, control certain harmful bacteria and insect pests, provide potential chemical precursors to produce biodiesel and for its use as feed for a variety of animals Nutritional value of BSF larvae is discussed, as well as the effect of biotic and abiotic factors on both larval body composition and performance Although BSF larvae contain high protein levels (from 37 to 63% dry matter; DM), and other macro- and micronutrients important for animal feed, the available studies on including BSF larvae in feed rations for poultry, pigs and fish suggest that it could only partially replace traditional feedstuff, because high or complete replacement resulted in reduced performance This is due to factors such as high fat content (from 7 to 39% DM), ash (from 9 to 28% DM), and consequences of processing Therefore, further studies are needed on nutrient composit

Nutritional value of the black soldier fly (Hermetia illucens L.) and its suitability as animal feed – a review

Environmental impact of food waste bioconversion by insects: application of life cycle assessment to process using Hermetia illucens.

Annual review of earth and planetary sciences v. 7, Editor: F. A. Donath; Associate Editors: F. G. Stehli, and G. W. Wetherill, Annual Reviews, Inc., 4139 El Camino Way, Palo Alto, California, 94036, 1979, 517p., 17 (U.S.), 17.50 elsewhere

Rethinking organic wastes bioconversion: Evaluating the potential of the black soldier fly (Hermetia illucens (L.)) (Diptera: Stratiomyidae) (BSF).

Black soldier fly (BSF) larvae (Hermetia illucens), feeding on leachate from decaying vegetable and food scrap waste, increase ammonia (NH
 4
 +
 ) concentration five- to sixfold relative to leachate unprocessed by larvae. NH
 4
 +
 in larva-processed leachate reached levels as high as ∼100 mM. Most of this NH
 4
 +
 appears to have come from organic nitrogen within the frass produced by the larvae as they fed on leachate. In nitrate-enriched solutions, BSF larvae also facilitate dissimilatory nitrate reduction to ammonia. The markedly higher concentration of NH
 4
 +
 recovered in leachates processed with BSF larvae and concomitant diversion of nutrients into insect biomass (itself a valuable feedstock) indicate that the use of BSF larvae in processing leachate of decaying organic waste could be advantageous in offsetting capital and environmental costs incurred in composting.

Enhanced Ammonia Content in Compost Leachate Processed by Black Soldier Fly Larvae

A large number of biodegradable byproducts including alcohols, soluble saccharides, volatile organic acids, and amines accumulate in the liquid fraction (leachate) produced as vegetal and food scrap waste decomposes. Untreated leachate, because it is rich in nutrients and organic byproducts, has a high chemical oxygen demand and is normally cleared of soluble organic byproducts by mineralization before its discharge into waterways. Mineralizing leachates using chemical and microbial biotechnologies is, however, a lengthy and costly process. We report here that the larvae of the black soldier fly Hermetia illucens (L.) (Diptera: Stratiomyidae), an insect rich in protein and lipids, and having significant commercial value, while feeding and growing off of compost leachate, lowers its chemical oxygen demand relative to that of leachate unexposed to larvae, neutralizes its acidity, and clears it of volatile organic acids, amines, and alcohols. These observations demonstrate that black soldier fly larvae could be used to help offset the cost and clean up of organic solutes in leachate waste streams while recycling carbon, nitrogen, and phosphate into usable and commercially valuable biomass.

https://bioone.org/journals/journal-of-economic-entomology/volume-105/issue-2/EC11192/Using-Black-Soldier-Fly-Larvae-for-Processing-Organic-Leachates/10.1603/EC11192.pdf

Using Black Soldier Fly Larvae for Processing Organic Leachates

Disclosed herein are methods of removing organic solutes from liquids. The methods include incubating fly larvae with a liquid that contains organic solutes. Also disclosed herein are methods of producing larva biomass. Additionally, apparatus for use with the disclosed methods are described.

Insect-based removal of organic solutes from liquid

We propose that microaerobic composting (MC) can be used to decompose vegetal matter with a short turnover time and large carbon (C) recycling potential. We used a novel method for measuring the degree of fragmentation of water-insoluble acid-soluble (WIAS) polysaccharides as a proxy in tracking their relative degree of degradation (i.e., fragmentation endpoint index). Oak leaves and food scrap processed by MC reached a fragmentation end point within 2 weeks. After amending the MC products into soil, the half-life of the polysaccharide residues was ~6–7 times longer (~100–110 days) than that measured during MC. The main products given up during MC were volatile organic acids (VOAs), alcohols and soluble carbohydrates in the compost tea, and CO2. These products accounted for about 2% of the initial carbon in the feedstock. Very small amounts of VOAs, particularly butyric acid, were formed in the amended soil. Based on a residence time of materials in fermentors of 2 weeks, a ~100-m3 capacity MC facility could process 2,000–4,000 metric tons of vegetable matter amended in ten hectares of arable land per year.

/pdf/turnover-of-carbohydrate-rich-vegetal-matter-during-4ko295n7oe.pdf

Turnover of Carbohydrate-Rich Vegetal Matter During Microaerobic Composting and After Amendment in Soil

We describe a simple method for measuring cellulose in soil. We used this method to measure the recovery of shredded office paper and pure medium fiber cellulose added to a Helvetia silt loam clay soil. This method consists of solvating cellulose from soil with 77% H2SO4 and analysis of the cellulose recovered by the phenol-sulfuric acid carbohydrate assay. Unlike previous related methods the modifications we propose allow good recovery of cellulose (~99%) and eliminate the need to autoclave the samples. We verified this method on soil spiked with up to 12% cellulose and found a good linear relationship between the amounts of cellulose added relative to that recovered. With proper fragmentation and dilution of the acid-treated soil samples, higher concentrations can be easily measured. We propose this technique as a robust and high throughput means to monitor the degradation of cellulose in paper spiked soil.

Terrence R. Green

Papers

Enhanced Ammonia Content in Compost Leachate Processed by Black Soldier Fly Larvae

Using Black Soldier Fly Larvae for Processing Organic Leachates

Insect-based removal of organic solutes from liquid

Turnover of Carbohydrate-Rich Vegetal Matter During Microaerobic Composting and After Amendment in Soil

A Simple Assay for Monitoring Cellulose in Paper-Spiked Soil