How Many BSFL to Feed Your Reptile, by Species and Size
- Role
- Rotation supplement
- Protein
- ~18%
- Fat
- ~14%
- Moisture
- ~60%
- Chitin
- moderate
- Ca:P
- ~1.5:1
- Calcium-rich
- Yes
- Best for
- Natural calcium source — reduces dusting need
I think of black soldier fly larvae as a calcium-delivery feeder, not a protein staple, and that one distinction changes how you feed them. BSFL are the rare feeder insect that is naturally calcium-rich with a favorable calcium-to-phosphorus ratio, which is exactly the opposite of nearly every other feeder (roaches, crickets, mealworms, and silkworms are all phosphorus-heavy and need dusting). That natural calcium is the whole point of BSFL, so you use them differently: smaller quantities, fewer sessions per week, and no dusting.
BSFL Feeding Chart by Species
Counts below assume BSFL are a calcium supplement layered onto a protein staple, not the main feeder. Match larva size to the animal.
| Species | BSFL Size | Per Feeding | Frequency | Weekly Total |
|---|---|---|---|---|
| Baby bearded dragon (0-4 months) | Small | 10-20 | Daily (mixed with roaches) | 70-140 |
| Juvenile bearded dragon (4-12 months) | Small-medium | 10-20 | 2-3x/week | 20-60 |
| Adult bearded dragon | Medium | 10-15 | 1-2x/week | 10-30 |
| Leopard gecko (adult) | Small-medium | 5-10 | 1-2x/week | 5-20 |
| Chameleon (adult veiled/panther) | Small-medium | 5-10 | 1-2x/week | 5-20 |
| Jackson's chameleon | Small | 3-5 | 1x/week | 3-5 |
| Crested gecko | Small | 3-5 | 1x/week | 3-5 |
| Blue tongue skink | Medium-large | 15-25 | 1-2x/week | 15-50 |
| Frogs (dart frogs, tree frogs) | Small | 5-10 | 1-2x/week | 5-20 |
Why BSFL Amounts Differ from Roaches
BSFL play a different nutritional role than a protein feeder. With roaches you feed enough per session to meet protein needs. With BSFL you feed enough to top up calcium stores, but not so many that the fat content becomes a problem. Think of BSFL like a calcium supplement in feeder form: consistent, moderate amounts spread across the week rather than one big serving.
Do NOT Dust BSFL
This is the part keepers get wrong most often. BSFL already carry more calcium than a dusting of powder would add, and their calcium-to-phosphorus ratio is naturally positive. Dusting them is redundant and wasteful. Keep your calcium powder for the feeders that actually need it, mainly roaches and silkworms. If you want the underlying reasoning on calcium-to-phosphorus balance and reptile bone health, the Merck Veterinary Manual on reptile nutrition is a solid non-commercial reference.
Can You Feed Too Many BSFL?
Yes. BSFL are excellent for calcium but run around 14% fat, so using them as a sole daily staple would push too much fat into most adult diets. Use them as a supplement, roughly 1-3 feedings per week, alongside lean protein feeders like discoid roaches and very lean variety feeders like silkworms.
Baby bearded dragons are the exception. They can take BSFL more often, even daily mixed with roaches, because rapid bone growth demands high calcium and their fast metabolism burns the fat efficiently.
Feeding Method
- Dish feeding: drop BSFL into a smooth-sided dish or bowl. They can't climb smooth walls, so they stay contained, and most reptiles learn the dish quickly.
- Tong feeding: offer individual larvae with soft tongs for interactive feeding. Works well for chameleons and geckos.
- Cup feeding (chameleons): attach a small cup to a branch at eye level and let the chameleon shoot larvae from the cup.
BSFL Size Guide
- Small: leopard geckos, dart frogs, small chameleons, hatchling bearded dragons.
- Medium: adult leopard geckos, adult chameleons, juvenile bearded dragons.
- Large: adult bearded dragons, blue tongue skinks, tegus.
As always, keep prey no wider than the space between your reptile's eyes. You can stock up at All Angles Creatures black soldier fly larvae. Use them for what they do best, calcium, and let a protein staple carry the rest of the diet.
See also my leopard gecko feeding chart and silkworm feeding chart, plus the full exotic-animals guide hub.