Influence of Substrate Type, Moisture, and Compaction on Pupation and Adult Emergence of Black Soldier Fly ( Hermetia illucens )

Black soldier flies, Hermetia illucens (L.) (Diptera: Stratiomyidae), are of particular interest for their applications in waste management. Feeding on decaying organic waste, black soldier flies successfully reduce manure in confined animal feeding operations of poultry, swine, and cattle. To optimize waste conversion in confined animal feeding operations and landfill facilities, it is imperative to optimize black soldier fly development. Unfortunately, black soldier flies only convert waste during their larval feeding stages and therefore it is of interest to optimize the nonfeeding stages of development, specifically, the postfeeding and pupal stages. The time spent in these stages is thought to be determined by the pupation substrate encountered by the postfeeding larvae. The objective of this study was to determine the effect different pupation substrates have on postfeeding development time, pupation time, and adult emergence success. Five pupation substrates were compared: wood shavings, potting soil, topsoil, sand, and nothing. Postfeeding larvae took longer to reach pupation in the absence of a pupation substrate, although reaching pupation in the shortest time in potting soil and wood shavings. The time spent in the pupal stage was shortest in the absence of a pupation substrate. However, fewer adults emerged when a pupation substrate was not provided.

Context Black soldier fly larvae are a promising alternative ingredient in poultry feed. They might be able to replace soybean and fishmeal because the have high concentrations of protein and fat, and are also rich in vitamins and minerals, and because partial replacement of soybean and total replacement of fishmeal produce no adverse effect on the growth performance of village chickens. Therefore, they are a suitable replacement for these traditional ingredients in poultry feed. Aims This study determines the nutritive values of black soldier fly larvae and evaluates the effects of feeding diets containing black soldier fly larvae on the growth performance of village chickens. Methods Samples of black soldier fly larvae were subjected to proximate analysis before a total of 280 1-day-old village chicks were randomly divided into four groups. All groups were fed a basal diet with partial replacements of corn and soybean with black soldier fly larvae at 0% (Control), 5% (T1), 10% (T2) and 15% (T3) for 70 days. Each treatment group consisted of seven replicates, with 10 birds per replicate. The bodyweights, bodyweight gains and feed conversion rates were determined. Key results Dry rendered black soldier fly larvae contained 773.0 ± 0.08 g/kg dry matter, 36.1 ± 0.09 g/kg ash, 408.8 ± 0.28 g/kg crude protein, 283.0 ± 0.16 g/kg ether extract and 40.9 ± 0.44 g/kg crude fibre. The larvae also contained 2.041 MJ/kg of metabolisable energy, 20.4 g/kg of calcium and adequate concentrations of vitamins. The feeding trial showed an average bodyweight gain of 1231.45 ± 23.37 g and feed conversion ratio of 2.03 ± 0.15, which were most efficient with Diet T3. Conclusions Inclusion of 15% black soldier fly larvae in diets can enhance the growth performance of village chickens without adverse effects. Implications Partial replacement of soybean and total replacement of fishmeal in the diet of chickens by black soldier fly larvae are not affecting the growth performance of village chickens but might reduce the feed cost.

The growth and development of black soldier fly, Hermetia illucens (L.), larvae fed chicken manure inoculated with bacteria isolated from black soldier fly larvae and associated larval feed was evaluated. Four strains of Bacillus subtilis were evaluated. B. subtilis strains S15, S16, S19, were isolated from the gut of black soldier fly larvae. B. natto strain D1 was isolated from the diet fed to black soldier fly larvae. These bacteria were added individually into nonsterile 200 g fresh hen manure at 10(6) cfu/g and homogenized. Treated manure was then inoculated with 4-d old black soldier fly larvae. Prepupal weight ranged from 0.0606 g in the control to 0.0946 g in manure treated with the S15 strain. Larval survivorship to the prepupal stage in all treatments ranged from 98.00 ± 2.65% to 99.33 ± 1.15%. Prepupal survivorship to the pupal stage ranged from 91.92 ± 1.87% to 97.95 ± 1.03%. Adult emergence from the pupal stage did not significantly (P < 0.05) differ across treatments and ranged from 98.95 ± 1.82% to 100.00 ± 0.00%. Adult body length resulting from the larvae in each of the treatments was significantly greater than those from the control. Longevity of adults did not differ significantly between treatments. Time from hatching to the development of the first pupa did not differ significantly across treatments; however, development time from hatching to 90% reaching the prepupual stage was significantly different between treatments and ranged from 29.00 ± 1.00 d to 34.33 ± 3.51 d. Development time from hatching to 90% reaching the adult stages was significantly different between treatments. Our results demonstrate that inoculating poultry manure with bacteria from black soldier fly larvae influences the growth and development of conspecific larvae feeding on the manure.

The purpose of this experiment was to evaluate the effects of dietary replacement of fish meal by black soldier fly (BSF) larvae on growth performance, blood profiles, immune response, and diarrhea incidence in weaning pigs. A total of 160 weaning ([Yorkshire × Landrace]) × Duroc) pigs (7.47 ± 0.02 kg body weight [BW]) were assigned to four treatments based on sex and initial body weight, with five replicates of eight pigs per pen in a randomized complete block design (RCBD). Experimental diets with black soldier fly (BSF) larvae replaced fish meal (FM) at 0, 25, 50, and 100% for phase I (0 to 2 weeks). Phase II (3 to 4 weeks) were as follows: 1) Control: corn‒soybean-based diet containing FM 4%, 2) BSF25: corn‒soybean-based diet containing FM 3% and BSF larvae 1%, 3) BSF50: corn‒soybean-based diet containing FM 2% and BSF larvae 2%, 4) BSF100: corn‒soybean-based diet containing BSF larvae 4%. The study found no significant differences among the treatment groups in BW and ADG during the experimental period. However, an increased tendency of ADFI was observed (linear, p=0.09), and G:F ratio tended to decrease as the replacement rate of fish meal with BSF larvae increased (linear, p=0.06). During phase I, creatinine concentration decreased linearly as BSF larvae level increased (linear, p=0.02). During phase II, a linear response was observed in the change of glucose concentration as an increase in BSF larvae level (linear, p=0.02). Meanwhile, pigs fed with increasing BSF larvae levels showed increased albumin and total protein concentration trends (linear, p=0.05, p=0.05). Defatted BSF larvae can replace up to 50% of FM in weaning pig diets without detrimental effects on performance, blood metabolites, or immune response.These reassuring findings suggest that BSF larvae could be a sustainable and effective replacement for fish meal in pig diets.

Can black soldier fly (BSF) larvae be a protein substitute for managing adverse food reactions (AFRs) in dogs, specifically those with dermatitis? We evaluated BSF larvae's safety, tolerance, and effectiveness as a novel protein source in dogs with AFRs. Sixteen dogs, including eight healthy controls and eight diagnosed with AFRs, were fed a diet containing BSF larvae for four weeks. Skin conditions, including dermatological lesions and Pruritus Visual Analog Scale (PVAS) scores, and gastrointestinal signs, including relevant clinical signs, stool consistency, and hematological and biochemical parameters, were monitored. No significant gastrointestinal side effects were observed. The control and AFRs groups maintained stable body weights, while stool consistency scores did not change significantly. Moreover, skin reaction data obtained before the study were collected through interviews with the owners. The mean PVAS scores in the AFRs group were significantly higher (p < 0.05) during the self-control period (6.0 ± 1.6) when compared with other periods. However, no significant differences (p > 0.05) were observed between the pre-study baseline (2.0 ± 1.1) and scores at 2 weeks (2.3 ± 1.5) and 4 weeks (2.4 ± 1.2) of feeding with BSF-based food, which indicated that BSF larvae did not exacerbate pruritic symptoms. Hematology and blood chemistry remained within normal ranges in all dogs, indicating no adverse effects on overall health. BSF larvae were well tolerated by AFR-affected and control dogs, with no adverse clinical outcomes. The findings suggest that BSF larvae may offer a better, sustainable alternative protein source for managing AFRs in dogs, particularly in those on hypoallergenic diets. Further long-term studies are needed to confirm these results and assess the broader implications of BSF larvae diets on canine health.

Black soldier fly (Hermetia illucens) larvae are a promising source of protein and lipid for animal feeds. The nutritional composition of the BSF larvae depend partly on the composition of the feeding medium. The BSF lipid profile in part mimics the feeding media lipid profile, and micronutrients, like minerals and vitamins, can readily accumulate in black soldier fly larvae. However, investigative studies on bioconversion and accumulation of nutrients from media to black soldier fly larvae are scarce. Here we show that inclusion of the brown algae Ascophyllum nodosum in the substrate for black soldier fly larvae can introduce valuable nutrients, commonly associated with the marine environment, into the larvae. The omega-3 fatty acid eicosapentaenoic acid (20:5n-3), iodine and vitamin E concentrations increased in the larvae when more seaweed was included in the diet. When the feeding media consisted of more than 50% seaweed, the larvae experienced poorer growth, lower nutrient retention and lower lipid levels, compared to a pure plant based feeding medium. Our results confirm the plasticity of the nutritional make-up of black soldier fly larvae, allowing it to accumulate both lipid- and water-soluble compounds. A broader understanding of the effect of the composition of the feeding media on the larvae composition can help to tailor black soldier fly larvae into a nutrient profile more suited for specific feed or food purposes.

Large-scale insect rearing for food and feed production can be improved by understanding diet digestion and host–microbe interactions. To examine these processes in black soldier fly (Hermetia illucens L.; Diptera: Stratiomyidae) larvae, two protocols were developed. Protocol 1 describes a method to produce viable, sterile black soldier fly larvae and a gentle method for diet sterilization. Sterile black soldier fly larvae can be used to study the diverse role of microbes in larval development. Nutrient requirements of sterile black soldier fly larvae are met only through diet. Viable sterile black soldier fly larvae were consistently generated using a four-step treatment with alternating immersions of eggs for 2 min each in ethanol (70%) and sodium hypochlorite (0.6%), over two cycles. A nonthermal method of diet sterilization, namely high-energy electron beam (HEEB) treatment, was introduced. Subsequently, growth of sterile black soldier fly larvae was observed on the HEEB-treated diets (40, 60, and 40% of replicates with poultry feed, liver pie, and an artificial diet, respectively) but not on autoclaved diets. In Protocol 2, we propose a novel method to collect frass from individual larvae. We then measured the metabolites in frass, using high-pressure liquid chromatography. Results on metabolites confirmed the influence of digestion. For instance, succinate increased from 1 to 2 and 7 μmol/g sample from diet to gut homogenate and frass, respectively. The collection method is a promising tool to estimate the diet and nutrient requirements of black soldier fly larvae, thus increasing the performance and reliability of black soldier fly larvae rearing. We discuss in detail the possible applications and limitations of our methods in black soldier fly larvae research.

This study aimed to evaluate the in sacco nutrient degradability of total mixed ration (TMR) silage containing intact and defatted black soldier fly (BSF) larvae. The study evaluated four dietary treatments and six replications. The treatments consisted of control TMR silage without BSF larvae (R1), 20% intact BSF larvae + 80% TMR silage (R2), 20% chemically defatted BSF larvae + 80% TMR silage (R3), and 20% mechanically defatted BSF larvae + 80% TMR silage (R4). Samples were placed in polyester bags and incubated in the rumen in sacco up to 72 h. Nutrient degradability was evaluated for each time point interval. Results revealed that the lowest dry matter degradability (DMD) was found in R1 compared to all treatments (p &lt; 0.05), while the highest DMD was found in R2 (p &lt; 0.05). The highest organic matter degradability was found in R2 compared to R1, R3 and R4 (p &lt; 0.05). Addition of BSF larvae to TMR silage increased the crude protein degradability (p &lt; 0.05). In conclusion, inclusion of both intact and defatted BSF larvae into TMR silage did not have any adverse effects on nutrient profiles and showed a good nutrient degradation values in the rumen.

In recent years, interest in the larvae of black soldier fly (BSF) (Hermetia illucens) as a sustainable protein resource for livestock feed has increased considerably. However, knowledge on the nutritional and physiological aspects of this insect, especially compared to other conventional farmed animals is scarce. This review presents a critical comparison of data on the growth potential and efficiency of the BSF larvae (BSFL) compared to conventional monogastric livestock species. Advantages of BSFL over other monogastric livestock species includes their high growth rate and their ability to convert low-grade organic waste into high-quality protein and fat-rich biomass suitable for use in animal feed. Calculations using literature data suggest that BSFL are more efficient than broilers, pigs and fish in terms of conversion of substrate protein into body mass, but less efficient than broilers and fish in utilization of substrate gross energy to gain body mass. BSFL growth efficiency varies greatly depending on the nutrient quality of their dietary substrates. This might be associated with the function of their gastrointestinal tract, including the activity of digestive enzymes, the substrate particle characteristics, and their intestinal microbial community. The conceived advantage of BSFL having an environmental footprint better than conventional livestock is only true if BSFL is produced on low-grade organic waste and its protein would directly be used for human consumption. Therefore, their potential role as a new species to better close nutrient cycles in agro-ecological systems needs to be reconsidered, and we conclude that BSFL is a complementary livestock species efficiently utilizing organic waste that cannot be utilized by other livestock. In addition, we provide comparative insight into morpho-functional aspects of the gut, characterization of digestive enzymes, gut microbiota and fiber digestion. Finally, current knowledge on the nutritional utilization and requirements of BSFL in terms of macro- and micro-nutrients is reviewed and found to be rather limited. In addition, the research methods to determine nutritional requirements of conventional livestock are not applicable for BSFL. Thus, there is a great need for research on the nutrient requirements of BSFL.

The emergence of black soldier fly larvae (BSFL) as one among the vital tools for generating circular economy has enabled its use in several applications such as biorefining, valorization of waste management, treatment of industrial by-products, and bioconversion of agro-industrial residues. The ability of BSFL to assimilate chemical constituents of interest from the feed substrate and easily recover them from the insect matrix gives it a bio-reactor like characteristic. The primary unit operation after insect harvesting is the devitalization technique employed, and further processing of BSFL depends on the end application of the insect product. Conventional drying, microwave drying, scalding, blanching, microwave-assisted subcritical condition, and freezing as devitalization techniques to euthanize BSFL was executed. The impact of the devitalization techniques on the BSFL oil, protein, antioxidant, and chitin fractions was evaluated. The crude lipid yield, fatty acid profile and lipid class composition were investigated. The fatty acid profile was uniform for BSFL fractions devitalized by different techniques, and triacylglycerides were the primary lipid class in the oil fraction. The protein solubility of the defatted BSFL flour in different pH was determined. The protein quality parameters such as protein dispersibility index, urease activity index, and molecular weight distribution of the soluble protein fractions were analyzed. The frozen BSFL fraction displayed the highest protein solubility in all pH range considered, protein dispersibility index (PDI) and protein solubility (PS) was 52.86 ± 2.99% and 83.94 ± 2.96%, respectively. The aminogram of dry defatted BSFL flour, BSFL concentrate and isolate were recorded and the nitrogen-to-protein conversion (Kp) value was determined for these fractions. The antioxidant capacity of water-soluble bioactive compounds of BSFL was evaluated. Radical scavenging capacity and total polyphenol content of the BSFL fraction devitalized by microwave-assisted subcritical treatment and freezing displayed higher values when compared to other BSFL fractions. The chitin fractions were characterized by determining the degree of acetylation. Devitalization techniques strongly influence and impact the major BSFL constituents except for chitin and selection of the method should depend on the end application of the insect product. The microwave-assisted subcritical treatment proved to be an efficient devitalization technique. Whereas, freezing being a non-thermal treatment has a few limitations. Graphic abstract

Effects of feeding unprocessed whole black soldier fly (Hermetia illucens) larvae on performance, biochemical profile, health status, egg quality, microbiome and metabolome patterns of quails

Meal of black soldier fly larvae (BSFL), which requires extraction of protein and fat, is a novel protein source for poultry, while unprocessed whole BSFL could even directly be fed to chickens. Newly hatched Ross-308 chicks (n = 252) received whole BSFL at 10% (L10), 20% (L20), or 30% (L30) of voluntary feed intake (FI) of control chickens (CON) that received no BSFL but only age-specific diets (n = 63 birds / group) for 42 days (d). Acceptance and nutrient and energy intake of birds by BSFL and FI were calculated. Plasma metabolites were measured using an automatic enzymatic analyzer and immunoglobulins with ELISA. Depending on the variable, data were analyzed using ANOVA or repeated measures ANOVA to address treatment, time and interaction effects. Birds consumed all offered larvae. With the exception of d1, time spent by birds eating their daily portion of larvae (TSL, min/pen) did not differ among the larvae supply groups (P = 0.982). The L10 had a higher larvae eating rate (LER) that is, speed of larvae intake than did L20 and L30 (P < 0.05), implying increased competition for less available BSFL. The ratio of LER to feed eating rate (FER) was greater than 50 fold change difference (FCD), indicating a strong interest of chickens in BSFL over regular feed. Whole BSFL intake up to 30% of voluntary FI did not adversely affect broiler growth (P > 0.05). The L30 had lower total dry matter and metabolizable energy intakes (P < 0.05), although total fat intake was higher in L30 than in CON (P < 0.05). Compared with CON, 30% whole BSFL increased dietary protein-to-energy ratios, plasma uric acid and serum alkaline phosphatase concentrations (P < 0.05). We conclude that whole BSFL can be included in broiler rations up to 20% without negatively affecting growth performance and nutrient conversion efficiency, whereas a higher proportion is associated with lower protein utilization efficiency, possibly due to lower total energy intake.

Mealworms and black soldier fly (BSF) larvae are two of the most reared insects at an industrial scale. Both may feed on by-products from agricultural and food industries. Feed efficiency is one of the most important aspects of such processes and varies between species and feed substrates and depends on the metabolic performance of the larvae. Compared to each other, both species may hold advantageous capabilities affecting their feed efficiency, likely depending on the feed substrate. We reared mealworms and BSF larvae on a diverse selection of by-products from agricultural and food industries, quantified major metabolic rates across their life spans, and compared their performances. The type of feed substrates had stronger effects on the growth of mealworms than on black soldier fly larvae. Generally, BSF larvae were advantageous in terms of the highest maximal specific growth rate (0.50-0.77 day-1) and feed assimilation rate (0.81-1.16 day-1) and shortest development period (23-25 days) but disadvantageous in terms of metabolic maintenance cost (0.07-0.21 day-1). In mealworms, the maximal specific growth rates were 0.02-0.11 day-1, the highest feed assimilation rates were 0.16-0.37 day-1, and the development period was at least 65-93 days, while maintenance was only 0.02-0.05 day-1. In contrast to the BSF larvae, the specific maintenance rate was weight dependent in the mealworms and lowest in the largest individuals. The combined outcome of these metabolic rates resulted in an average carbon net growth efficiency, NGE*avg of 0.16-0.40 in mealworms and 0.33-0.56 in BSF larvae across their life span. It thus seems that BSF larvae are more versatile and somewhat more efficient at converting diverse feed substrates into growth than mealworms. Differences in NGE*avg affected the substrate conversion efficiencies (i.e., the ratio of the weight gain of the larvae to the reduced weight of feed substrates) and may thus impact the overall outcome of insect farming.

This study investigates the potential of Black Soldier Fly (BSF) larvae in managing organic waste through rapid decomposition and nutrient-rich compost production. The primary objective was to evaluate the efficiency of BSF larvae in waste reduction and compost quality, particularly within urban environments, and to explore their scalability in urban waste management systems. The methodology involved controlled experiments to measure bioconversion rates at varying larval densities, temperature, and moisture levels. The compost produced by BSF larvae was analyzed for key nutrients, including nitrogen, phosphorus, and potassium. The results demonstrated that BSF larvae effectively reduced organic waste by up to 86% within a few days, outperforming traditional composting methods. The compost produced was rich in essential nutrients, making it suitable for urban farming. Factors such as optimal larval density, temperature, and moisture content were crucial for maximizing decomposition efficiency and compost quality. However, the study also identified several challenges, including space constraints, public perception, and the logistical difficulties of scaling BSF larvae systems in urban areas. In conclusion, this research highlights the potential of BSF larvae as a sustainable solution for organic waste management, compost production, and urban farming. The findings contribute to the growing knowledge on sustainable waste management and urban agriculture, offering insights into integrating BSF larvae systems into existing waste management frameworks. Future research is needed to address scalability challenges and optimize the operational efficiency of BSF larvae systems in urban environments.

The bioconversion of organic solid waste utilizing Black Soldier Fly (BSF) larvae was used to reduce the unstable domestic supply of feed protein in Indonesia due to currency change dynamics. BSF larvae are a well-known bioconversion agent capable of producing high protein content in their body mass. Therefore, this research aims to conduct a small-scale bioconversion process of domestic and industrial organic solid wastes to produce dry BSF larvae as a protein source for chicken and fish culture. The research was held at Bogor, Indonesia, from March-June 2021, where organic solid waste from a restaurant was bioconverted by BSF larvae in a biopond. After two weeks, the BSF larvae were harvested, dried, and milled to produce the powder. Based on SNI 7548:2009, the quality of pellets from BSF larvae and pupae was appropriate, except for the parameters of fat content in pellet A and water and ash content in pellet B. The results showed that fish pellets mixed with 20% protein flour affected the weight growth of Pangasius sp. Furthermore, when dried BSF larvae powder was applied to one-day-old chickens, they grew somewhat quicker than the standard feed menu. Therefore, organic solid waste, when appropriately managed, produces feed protein.