MRP: Optimising rearing conditions for black solider flies – Julian Beniers

Julian Beniers is a man with a mission. Before he even applied for the MSc course, he had formulated his Master’s Research Project (MRP), methods and all. During his BSc at HAS University of Applied Sciences, he started a project on black solider flies (Hermetia illucens) and became interested in their biology and behaviour. He then furthered this interest when doing an internship with the same species before coming to Harper Adams University (twitter: @HarperAdamsUni). By the time he arrived in Shropshire, his MRP was complete in all but execution.

Julian will be investigating the effect of protein and carbohydrate levels in black solider fly larvae foods and its relation to larval mass over the course of larval development, and potentially macronutrient levels within the larvae too (time permitting). He wants to answer the question “When do black soldier fly larvae begin producing large fat reserves, and specifically, at what weight does this normally occur?”. Black solider fly larvae rapidly become larger during their first instars and protein is likely to the most important macronutrient of their diet, whereas later in larval development, carbohydrates and fats may become more important. To answer his research question, Julian will attempt to map protein and fat content of larvae at precise intervals throughout their development by killing, drying and subjecting the dried tissue to Soxhlet and leco fat and protein analysis, respectively. He’ll also be using a variety of different foods with varying levels of protein and carbohydrate to see if these can be used to determine an optimal diet and growth rate. He suspects the larval mass at which a change in macronutrient storage occurs in between 140-160 mg.

This research is potentially quite commercially important because of the widespread use of black soldier fly larvae in the pet trade (food for exotic pets) and in human entomophagy (food for us). Interestingly, Julian gently suggests that this research may actually have been done before internally within pet food companies, however, as the Robin Hood of trade secrets, Julian attempts to get this research published, which could make things easier for other companies and independent rearers.

More generally, Julian is an avid keeper of entomofauna and is curious about the upcoming entomophagy industry in the West (an age-old industry in other parts of the world); he is planning to attend the Royal Entomological Society’s entomophagy day on April 4th.

Please don’t hesitate to contact me (details below) or Julian with advice or questions (twitter: @Julianosaurus; email:; LinkedIn).


Featured photo: Black solider fly larvae – photographed by Julian Beniers, of course!

Blog written by Max Tercel (email:; twitter: @MaximumInsect).