Black soldier fly (BSF) larvae for insectivorous reptiles: a real upgrade?
Published by Planète Pets · managing editor: Clément Lacaille · how our guides are written
Black soldier fly larvae, Hermetia illucens (often sold as "BSF" or "phoenix worms"), are gaining ground as live feeders for insectivorous reptiles. Their partly mineralised exoskeleton gives them a reputation as a naturally calcium-rich prey, an argument that appeals to owners of leopard geckos and bearded dragons. A benchmark study on the nutrient composition of several commercial feeder insects, published by Finke (2013) in Zoo Biology, confirms that black soldier fly larvae show the most complete profile among the insects compared, with the fewest deficiencies relative to an insectivore's nutritional needs (see the study). Calcium nonetheless remains a point of caution common to nearly all live feeders.
What BSF larvae actually bring
Compared with crickets or mealworms, black soldier fly larvae show a markedly better calcium-to-phosphorus ratio thanks to their calcified cuticle. They also contain less fat than mealworms or superworms, making them a useful option for limiting obesity in a sedentary adult bearded dragon. Their tougher shell can put off very young hatchlings, though: they're best reserved for animals able to chew them properly.
Fitting them into a balanced ration
Despite their good profile, BSF larvae don't remove the need for regular calcium and vitamin supplementation or prey variety: no single insect covers every requirement. Alternate them with crickets or other gut-loaded feeders, matching size to the animal's build. They keep well refrigerated, which simplifies storage compared with more fragile live crickets.
Frequently asked questions
Do BSF larvae replace calcium powder?
No. Their calcified exoskeleton is a plus, but supplementation is still recommended, especially for growing juveniles and breeding females.
Which reptiles can eat them?
Leopard geckos, bearded dragons and most insectivorous lizards accept them well; check the larva's size against the gap between the animal's eyes.
Where can you find them?
At specialist pet shops or online, live or dried; live larvae are best for the behavioural enrichment of hunting.
An accessory from our shop for this use: Ventilated clear box for feeder insects, transport and quarantine, 19 cm (€17.90) · the whole shop
This guide is part of Planète Pets’s Reptiles universe. Our advice is general in nature: for any health concern, your veterinarian remains the only reference.
