BSFL vs Mealworms: Which Feeder Is Better?
Matt GorenShare
BSFL vs Mealworms: A Complete Comparison
Black soldier fly larvae (BSFL) and mealworms are both popular feeder insects, but they serve very different nutritional roles. The difference is most dramatic in calcium — BSFL contain 311 times more calcium than mealworms. This comparison breaks down every metric that matters.
Nutritional Comparison
| Nutrient | BSFL | Mealworms | Winner |
|---|---|---|---|
| Protein | ~17% | ~20% | Mealworms (slightly) |
| Fat | ~14% | ~13% | Similar |
| Calcium | 9,340 mg/kg | 30 mg/kg | BSFL (311x more) |
| Ca:P Ratio | 6.92:1 | 0.04:1 | BSFL (173x better) |
| Dusting Required? | No | Yes (heavily) | BSFL |
| Chitin | Moderate (soft) | High (tough) | BSFL |
| Safe for juveniles? | Yes | No (impaction risk) | BSFL |
| Storage | Fridge, 2-3 weeks | Fridge, 2-4 weeks | Similar |
The Calcium Gap
This is the defining difference. Mealworms at 0.04:1 Ca:P have one of the worst calcium profiles of any feeder insect. They contain 25 times more phosphorus than calcium, meaning every mealworm feeding actively depletes your reptile's calcium stores — even with dusting.
BSFL at 6.92:1 do the opposite: they deliver a massive calcium surplus that builds and maintains healthy bones. This is why mealworm-heavy diets are strongly associated with MBD, while BSFL are a frontline defense against it.
Digestibility and Safety
Mealworms have a tough chitin exoskeleton that becomes harder to digest as the worms grow. This poses a real impaction risk for juvenile reptiles — most veterinarians recommend no mealworms for bearded dragons under 6 months. BSFL are softer-bodied and safe for all ages.
Storage
Both store well in the refrigerator. Mealworms go dormant and last 2-4 weeks. BSFL go dormant and last 2-3 weeks. Both require no feeding during refrigerated storage. This is essentially a tie.
Cost
Mealworms are cheaper per unit — among the cheapest feeders available. BSFL cost more. But when you factor in the calcium supplementation (calcium powder) that mealworms require and BSFL do not, the gap narrows.
Best Use for Each
BSFL: Calcium supplement, 1-3x/week. No dusting needed. Safe for all ages. Use alongside discoid roaches (protein staple).
Mealworms: Convenient fridge snack for adult reptiles only. Cheap backup feeder. Always dust heavily with calcium. Avoid for juveniles.
The Verdict
For calcium delivery and safety, BSFL win by an enormous margin. For raw protein and budget, mealworms have a narrow edge. The ideal approach: use BSFL for calcium supplementation and discoid roaches as your protein staple — mealworms become optional.
— Matt, Founder, All Angles Creatures
