Massey University Advances Black Soldier Fly Larvae for Sustainable Feed from Waste

🪰 Unlocking the Potential of Black Soldier Fly Larvae at Massey University

New Zealand's agricultural sector stands at a crossroads, grappling with mounting food waste, reliance on imported protein feeds like soybean meal and fishmeal, and the urgent need for sustainable practices. Enter the black soldier fly larvae (BSFL), scientifically known as Hermetia illucens, a humble insect poised to revolutionize waste management and animal nutrition. At Massey University, researchers are at the forefront of this innovation, pioneering methods to convert organic waste into high-quality protein-rich feed. This work not only addresses environmental challenges but also bolsters New Zealand's circular bioeconomy, making higher education a key driver in practical, real-world solutions.

Massey's efforts span ecology, animal science, and food technology, with studies demonstrating BSFL's ability to process diverse wastes—from household scraps and orchard by-products to brewery spent grain and biosolids—into valuable biomass. The larvae's rapid lifecycle and voracious appetite make them ideal bioconverters, consuming up to twice their body weight daily while producing nutrient-dense outputs. This research aligns perfectly with New Zealand's goals for regenerative agriculture and reduced landfill dependency, positioning Massey as a hub for sustainable protein innovation.

The Biology and Lifecycle of Black Soldier Fly Larvae

Black soldier flies are non-pest insects native to tropical and subtropical regions but adaptable to controlled environments in temperate climates like New Zealand. Adult flies lay eggs that hatch into larvae within days. These larvae, the star of the show, go through six instars over about 14-15 days, voraciously feeding on organic matter before entering the prepupal stage where they migrate to pupate.

The process is remarkably efficient: larvae use specialized digestive enzymes to break down complex lignocellulosic materials, converting indigestible waste into their bodies. On average, one kilogram of larvae processes significant volumes, yielding two to three kilograms of frass—a nutrient-rich fertilizer—and reducing input waste by up to 80 percent. Massey's controlled rearing systems maintain optimal conditions: temperatures of 25-30°C, 70-80 percent humidity, and carefully selected substrates to maximize growth and minimize pathogens.

Massey's Pioneering Research on Waste-to-Protein Conversion

Massey University's School of Agriculture and Environment has produced groundbreaking theses and studies on BSFL. Amira Elsayed Abdalla Mahmoud's 2024 PhD thesis, "Investigations on black soldier fly production and nutrition," provides a comprehensive guide for small- to medium-scale operations. Over her doctoral work, Mahmoud produced 450 kilograms of BSFL and prepupae, optimizing rearing from egg to meal processing. Key innovations include a novel sex separation method and identification of poultry red mites as a new threat, emphasizing hygiene protocols.

Earlier, Kevin Somera's 2018 Master's thesis focused on brewery spent grain—a major NZ waste stream—yielding 3.33 kilograms of dry biomass per kilogram of input larvae at an 18:1 feed ratio. Experiments tested feeding regimes, confirming weekly full feeds without frass removal as optimal, with heat-based harvesting at 32-39°C proving cost-effective. These studies quantify mass balances: for instance, 1142 kilograms dry spent grain inputs led to 270 kilograms dry prepupae, with 615 kilograms carbon released as CO2.

Associate Professor Maria Minor's ecology team explores BSFL's role in soil health, while Professor David Thomas's animal nutrition group assesses feed integration. Their work underscores BSFL's dual output: protein-packed larvae (31-59 percent protein, 15-49 percent fat, diet-dependent) and frass fertilizer.

Step-by-Step: How BSFL Converts Waste to Feed

1. Substrate Preparation: Organic wastes like food scraps, spent grain (pH 4.2-5.3, 70 percent moisture), or biosolids are pre-treated to 65-80 percent moisture, avoiding mould via aeration.
2. Inoculation: One-week-old larvae (27 mg dry weight) are added at ratios like 1:18 (larvae:dry feed).
3. Feeding and Growth: Over 14 days at 27°C, larvae consume, respire (0.06-0.21 mg O2/hour/larva), and grow, converting 24-27 percent of nitrogen.
4. Harvesting: Prepupae self-harvest or via sieves/heat; larvae dried to meal (41 percent protein, 30 percent fat dry basis).
5. Outputs: Larval meal for feed, frass for soil amendment (reduces waste volume 80 percent).

This closed-loop system recycles nutrients, with Massey's pilots confirming scalability.

Nutritional Superiority: BSFL in Poultry and Beyond

Massey's trials reveal BSFL meal outperforms soybean meal in broiler chickens. Full-fat BSFL provides higher apparent metabolizable energy (AME) and standardized ileal digestibility (SID) for amino acids. In one study, BSFL replaced soybean at 10-20 percent inclusion, supporting growth without compromising performance. Pigs and chickens showed effective nutrient uptake, with BSFL's taurine boosted by meat-waste diets.

For aquaculture—vital in NZ—BSFL offers a fishmeal alternative, rich in essential fatty acids. Pet food uses prepupae as prebiotics. However, amino acid profiles require supplementation for full replacement, as noted by Prof. Thomas: “The amino acid content can be influenced by what they are fed.”

Optimizing Production: Key Findings from Massey Labs

• Substrates: Spent wheat middlings best for pupation; brewery grain yields 27 percent biomass conversion.
• Moisture/Compaction: 10 percent moisture and mild compaction enable substrate reuse, cutting costs.
• Disease Control: First NZ report of red mites; hygiene prevents infestations.
• Scale-Up: Pilot cabinets for 80 kg waste; full plant processes 26 tonnes weekly, IRR 31 percent, NPV $2.1M.

Dr. Minor highlights: “They process waste in roughly 15 days, reducing volume by up to 80 percent.”

New Zealand's Agricultural Landscape and BSFL Fit

With dairy, poultry, and salmon farming dominant, NZ imports 65 percent of chicken feed proteins. BSFL tackles 1.4 million tonnes annual food waste, plus horticultural residues. Partnerships like Veolia's insect pilot and Good Grub Agritech scale commercialization. At 2026 Fieldays (June 10-13), Massey demos live BSFL processing (stand PE51).

Environmental and Economic Impacts

BSFL cuts greenhouse gases (no methane from landfills), conserves water (larvae need little), and repurposes nutrients. Economic models show profitability: $670k revenue from $270k costs annually. Frass enhances soil, closing loops for regenerative farming—a Massey strength.

Challenges and Massey's Solutions

Challenges include suboptimal amino acids, scaling hygiene, and regulations. Massey counters with diet tweaks (e.g., meat by-products for taurine), mite controls, and practical guides for SMEs. Regulatory approval for BSFL meal in NZ feeds advances via trials.

Future Outlook: Scaling BSFL from Massey to Industry

Massey's roadmap includes AI-optimized rearing, multi-substrate blends, and nationwide pilots. Collaborations with Plant & Food Research and industry aim for commercial plants by 2027. As global protein demand rises, this positions NZ universities like Massey as sustainability leaders, training students in biotech-ag intersections.

In higher education, programs in animal science and ecology at Massey equip graduates for green jobs, from BSFL farms to policy. This research exemplifies how NZ unis drive innovation for food security and climate resilience.

Photo by Elena Shirnina on Unsplash