Assessing the Nutritional Value of Black Soldier Fly Larvae (Hermetia illucens) Used for Reptile Foods
Semester of Graduation
Master of Science (MS)
Veterinary Clinical Sciences
Black soldier fly (BSF) larvae have been studied extensively in animal feed production, but there is limited research for non-production species, such as reptiles, despite their popularity as a calcium-rich feeder insect. The goals of this thesis were to determine the nutritive value of BSF larvae for a lizard species and as an ingredient in a diet formulated for snakes.
BSF larvae are deficient in fat soluble vitamins (A, D, and E). Using vitamin A as a test nutrient, several factors were identified that affect the success and consistency of gut loading. Based on the results, the following gut loading recommendations were established: vitamin A concentration of the larval diet should be between 16,000-20,000 mcg/kg, gut loading time period should be 24 hours, dietary moisture content should be between 56-65%, and larval density should be between 0.1-1 larvae/g of moist substrate.
Previous research in amphibians has suggested that BSF larvae have low digestibility. Using leopard geckos as a model, gut loaded and non-gut loaded larvae were fed as the primary diet for six months. Compared to the amphibian study, all nutrients were significantly more digestible, with the exception of calcium, as it likely remained bound to the undigested portions of the exoskeleton. Biochemistry results also revealed a possible calcium deficit occurring over time. Gut loaded vitamin A was confirmed to be digested as plasma and liver vitamin A concentrations were significantly higher in the gut loaded group (plasma: t=1.906, p=0.0415; liver: t=1.951, p=0.0325).
For carnivorous reptiles, an experimental sausage diet with BSF larvae as the primary protein was fed to juvenile corn snakes. The diet was fed for two months and compared to a diet of frozen-thawed mice. There was no significant difference between diet groups regarding health or growth parameters, suggesting that BSF larvae could be used to feed snakes.
The results of this work support the idea that BSF larvae are not a good source of calcium in their natural state, but that they can be gut loaded or used in a complete feed diet to provide the nutrients needed by reptiles to support health and growth.
Boykin, Kimberly L., "Assessing the Nutritional Value of Black Soldier Fly Larvae (Hermetia illucens) Used for Reptile Foods" (2019). LSU Master's Theses. 4927.