Evaluating sawdust as a bulking agent to enhance Black Soldier Fly Larvae (Hermetia illucens) performance and survival in potato peels

Description

Title of Dataset: Evaluating sawdust as a bulking agent to enhance Black Soldier Fly Larvae (Hermetia illucens) performance and survival in potato peels Research Hypothesis: We hypothesised that incorporating sawdust as a non-nutritive bulking agent into high-moisture potato peel substrates enhances the growth, yield, and survival of Hermetia illucens larvae by improving substrate aeration and moisture balance. Data Description and Methods: This dataset contains experimental data from a laboratory study conducted at the University of Venda. The aim was to evaluate the effect of varying sawdust inclusion levels (0%, 5%, 10%, and 15%) on the performance of BSFL reared on a standardised substrate of pulverised potato peels (40 kg) and spent grain (10 kg), with moisture content adjusted to 82% across treatments. Key data collected includes: Individual larval weight over time (sampled every two days) Growth rate (g/day) Final larval yield per tray (g dry weight) Larval survival (%) Treatment-level data including sawdust and water amounts, substrate composition, and moisture balance calculations Each treatment was replicated eight times. The rearing took place in a controlled environment using a staggered tray system to regulate temperature and humidity via infrared heating and ventilation. Larvae were sampled repeatedly for growth tracking, and harvest metrics were collected at the prepupal stage. Notable Findings: Sawdust inclusion at 10–15% significantly improved larval growth rate and yield compared to the Control and 5% sawdust treatments. No significant differences in larval survival were found across treatments (all above 65%), but 5% inclusion showed the highest survival rate. Peak larval weight was reached around day 10 post-inoculation, followed by weight reduction indicating the onset of metamorphosis. Sawdust likely improved substrate porosity and moisture regulation, facilitating enhanced larval movement and feeding efficiency. How the Data Can Be Interpreted and Used: This dataset provides insight into how physical modifications of substrate using bulking agents can influence BSFL rearing outcomes. The data can be used to: Model BSFL growth trajectories under different substrate structures Optimise bulking agent inclusion levels for industrial-scale BSFL farming Design substrate preparation protocols for high-moisture organic waste streams Explore moisture management strategies in insect-based bioconversion systems Format: Excel Workbook (.xlsx)

Steps to reproduce

How the data was gathered and how the research can be reproduced The data was generated through a controlled laboratory experiment conducted at the University of Venda to evaluate the effect of sawdust as a non-nutritive bulking agent on the growth, survival, and yield of Black Soldier Fly Larvae (BSFL) reared on high-moisture potato peel substrates. Experimental Design Design: A completely randomized design with four treatments (0%, 5%, 10%, 15% sawdust inclusion) and eight replicates per treatment. Substrate Preparation: A standardised mix of 40 kg potato peels and 10 kg spent grain was used. Sawdust (from Eucalyptus mannifera) was added at the specified inclusion rates. Moisture was adjusted to 82% across treatments using distilled water. Moisture Standardisation Protocol Initial Moisture Content: Determined gravimetrically using 10 g of each wet substrate dried in a laboratory oven at 100°C for 6 hours. Moisture Balancing: Water additions were calculated using substrate-specific moisture content values to ensure uniformity across treatments (Equation [2] in manuscript). Larval Source and Pre-treatment BSFL Source: Neonates (<24 h old) from a colony maintained at the University of Venda. Starter Mix: Neonates were reared on a 1:1:1 mix of potato peel, poultry pullet starter, and water for 5 days at 28°C in darkness to synchronise development. Rearing Setup Trays: 2,000 ml aluminium trays (100 mm deep) used as rearing units. Environment: Trays were incubated in a ventilated rearing chamber (4000 × 3500 × 1000 mm), equipped with infrared ceramic heaters (FTE-250W-230V) and fans to maintain temperature and moisture gradients. Staggered Design: Trays were introduced at two-day intervals to control for spatial and temporal variation. Sampling and Measurements Growth Monitoring: Every two days, 20 larvae were randomly sampled per tray, weighed using a four-decimal precision balance (ADAM PW214), and returned to the tray. Final Yield: At harvest, total prepupae biomass per tray was measured using a platform industrial scale. Individual weights were determined by sampling 20 prepupae per replicate. Dry Biomass: A 10 g subsample was dried at 100°C for 6 hours to calculate dry matter yield. Survival Rate: Calculated by dividing total harvested biomass by the mean prepupal weight, then dividing by the estimated number of initial larvae (based on average neonate weight of 0.000015 g). Software and Statistical Analysis All statistical analyses were conducted using R Statistical Software v4.3.1 (R Core Team, 2023). Generalised Linear Models (GLM) and Generalised Linear Mixed-Effects Models (GLMM) were implemented using lme4, multcomp, and car packages. Non-parametric comparisons were done using Kruskal-Wallis and Dunn's post hoc tests where normality assumptions were violated.

Institutions

• University of Venda

Categories

Funders

• National Research Foundation (NRF)

  Grant ID: 87311

Licence