Effects of feed nutrients on growth, development and the deposition of protein and fat in Tenebrio molitor larvae

Tamim, B.; Salter, A.; Parr, T.; Brameld, J.

Abstract

An understanding of the impact of dietary nutritional composition on growth, development and composition of Tenebrio molitor larvae (mealworms) could help optimise production systems. Replicate containers of mealworms fed for 24 days on synthetic cellulose-based feeds containing different combinations of protein (casein, Cas), lipid (wheat germ oil, WGO), carbohydrate (glucose) and a mineral/vitamin premix (MV) were compared to a control diet of wheat bran (WB). Mealworms fed only cellulose (C) ceased to grow after 10 days, and did not pupate. Addition of casein alone did not restore growth but did induce pupation (much slower than in WB-fed worms). Mealworms fed C+Cas-based diets showed a marked increase in the relative proportion of body protein to fat, compared to those fed wheat bran. The addition of MV to the C+Cas diet restored growth and pupation, though not to the same level as WB. MV-fed worms maintained a significantly increased protein/fat composition. The further inclusion of WGO or WGO + glucose further increased growth, whilst WGO + glucose reduced pupation. Overall, the highest yield of protein (per container) was seen in the C+Cas+MV+WGO-fed mealworms, which was 50% higher than in the WB group (largely due to the decreased pupation rate). Furthermore, the lipid yield was 50% lower than in WB-fed mealworms. By contrast, the addition of glucose to this diet maintained a high protein yield but increased the lipid yield to similar levels as seen in WB-fed mealworms, with an associated significant increase in the relative proportion of the polyunsaturated fatty acids (PUFA), linoleic and α-linolenic acids. The results indicate that sources of protein, lipid, minerals and multivitamins are all required to maximize protein whilst decreasing lipid deposition in mealworms. However, the addition of glucose (and presumably other digestible carbohydrates) increased lipid deposition and specifically the PUFA content.

Citation

Tamim, B., Salter, A., Parr, T., & Brameld, J. (2025). Effects of feed nutrients on growth, development and the deposition of protein and fat in Tenebrio molitor larvae. Journal of Insects as Food and Feed, 1-14. https://doi.org/10.1163/23524588-00001331

• Journal Article Type: Article
• Acceptance Date: Jan 6, 2025
• Online Publication Date: Jan 25, 2025
• Publication Date: Jan 25, 2025
• Deposit Date: Jan 29, 2025
• Publicly Available Date: Jan 29, 2025
• Journal: Journal of Insects as Food and Feed
• Electronic ISSN: 2352-4588
• Publisher: Wageningen Academic Publishers
• Peer Reviewed: Peer Reviewed
• Pages: 1-14
• DOI: https://doi.org/10.1163/23524588-00001331
• Keywords: mealworm; nutrient deposition; synthetic diet
• Public URL: https://nottingham-repository.worktribe.com/output/44689329
• Publisher URL: https://brill.com/view/journals/jiff/aop/article-10.1163-23524588-00001331/article-10.1163-23524588-00001331.xml?rskey=VDoVAf&result=1&ebody=article%20details