Discoid Roaches vs BSFL: Which Feeder Insect Is Better?
I breed discoid roaches and keep black soldier fly larvae on hand, and the most common mistake I see is treating these two as competitors. They're not. Discoid roaches (Blaberus discoidalis) are your protein workhorse. BSFL are your calcium powerhouse. Once you understand that split, you can build a rotation that covers both of the macro needs that matter most, without leaning on supplement powder for everything.
Nutrition side by side
| Metric | Discoid roaches | BSFL |
|---|---|---|
| Protein | ~20% | ~17% |
| Fat | ~7% | ~14% |
| Calcium | Low (needs dusting) | High (~9,000+ mg/kg) |
| Calcium:phosphorus | Phosphorus-heavy | Positive, ~1.5:1 |
| Moisture | ~61% | ~61% |
| Gut-loadable | Yes, highly | No |
The honest framing here matters. Discoid roaches are not calcium-rich; like nearly every feeder insect they carry more phosphorus than calcium, so you dust them with plain calcium. BSFL are the rare genuine exception: they're naturally high in calcium with a positive calcium-to-phosphorus ratio, which is exactly why you don't dust them.
When to use discoid roaches
Discoid roaches are the daily protein staple. At roughly 20% protein and only about 7% fat, they offer one of the best protein-to-fat ratios of any common feeder. They're also the single best gut-load candidate: feed them nutrient-dense vegetables 24 to 48 hours before offering them, and you turn each roach into a customizable nutrient delivery vehicle.
- Daily or 3 to 5x per week as the primary protein source
- Bearded dragons, leopard geckos, chameleons, monitors, tegus all take them readily
- All life stages, from small nymphs for juveniles to adults for large reptiles
- Long shelf life, six to twelve months at room temperature with basic care
- They don't bite and don't climb smooth glass, so an uneaten roach is harmless overnight
When to use BSFL
BSFL are the calcium feeder. They're the only common insect that reliably delivers more calcium than phosphorus, which means each one actively supports bone health rather than working against it, no dusting powder required.
- 1 to 3x per week as a calcium boost alongside roaches
- Juveniles and gravid females with elevated calcium demands
- Species prone to metabolic bone disease such as chameleons, beardies, and leos
- Cuts supplement dependence, since you're getting calcium from whole food
They're complementary, not competing
The strongest diet uses both. Roaches carry the protein load three to five days a week; BSFL deliver natural calcium one to three days a week. Add silkworms for low-fat variety and small hornworms for hydration and you've got a complete rotation built from whole feeders instead of relying on powder to patch a single-feeder diet.
Storage and care
This is where the two diverge most sharply, and it should factor into how you buy.
| Factor | Discoid roaches | BSFL |
|---|---|---|
| Shelf life | 6 to 12 months | 2 to 3 weeks |
| Temperature | Room temp (70 to 90°F) | Cool (50 to 60°F) |
| Feeding required | Yes, gut-load with veg | No, don't feed |
| Smell | None | None |
| Climbs glass | No | No |
Keep roaches warm and fed and they thrive for the better part of a year. Keep BSFL cool to slow their march toward pupation, and use them within a few weeks. If you see them darkening and turning into pupae, that's the clock running out.
The bottom line
If you can buy only one feeder, buy discoid roaches; they're the best all-around daily staple. If you can buy two, add BSFL for calcium. If you can buy four, round it out with silkworms and hornworms. You can browse discoid roaches at All Angles Creatures to start the rotation. For the underlying nutrition science on feeder insects, the Merck Veterinary Manual's reptile nutrition section is a reliable reference.
See also discoid roaches vs superworms and how to keep discoid roaches alive.