Discoid Roaches vs. Other Feeders: Optimizing Nutrition for Blue Tongue Skinks
If you keep a blue tongue skink, the insect side of its diet is worth getting right, because not all feeders are equal and skinks are big enough that the wrong ones add up fast. I get asked constantly where discoid roaches (Blaberus discoidalis) land against crickets, dubia, mealworms, and superworms. The honest answer: discoids are one of the best insect staples you can offer — with one correction to the usual sales pitch about their calcium.
What a blue tongue skink needs from a feeder
Blue tongue skinks (Tiliqua) are omnivorous lizards from Australia and nearby islands. In the wild they eat insects, snails, carrion, fruit, and greens, so a captive diet has to combine quality animal protein with plant matter and correct minerals. From the insect you specifically want:
- High, substantial protein for muscle and growth.
- Moderate fat — enough for energy, not enough to drive obesity (a real risk in captive skinks).
- Low chitin / soft body for easy digestion and low impaction risk.
- Size big enough to be a meal for a heavy-bodied lizard.
- Calcium delivered somehow — by dusting, because no feeder supplies enough on its own.
Hold every feeder up to those five and the picture gets clear.
Where discoids land nutritionally
Discoids hit the staple profile cleanly: roughly 20% protein as-fed, moderate fat around 6–7%, good moisture (~60–65%), and a soft, low-chitin body that digests easily — well suited to juveniles and adults alike. They gut-load exceptionally well and store for up to two years.
The one thing to correct: you'll constantly see discoids credited with a "favorable" or "balanced" calcium-to-phosphorus ratio that "reduces the need for supplementation." That's not true. Like nearly every feeder insect, discoids are phosphorus-heavy with poor calcium. So you dust with calcium (and D3 or a multivitamin on schedule) before feeding — every time, regardless of how well you gut-load. Skip it and you risk metabolic bone disease; the Merck Veterinary Manual explains why the ratio matters so much. Choose discoids for protein, digestibility, and ease — not for calcium they don't have.
The head-to-head
Treat these as approximate as-fed figures — real values shift with diet and life stage — but the relationships are what drive the decision.
| Feeder | Protein | Fat | Chitin / digestibility | Role for a skink |
|---|---|---|---|---|
| Discoid roach | High (~20%) | Moderate (~6–7%) | Low — soft, easy | Staple |
| Dubia roach | High (~20–23%) | Moderate (~7–9%) | Low — soft, easy | Staple |
| Cricket | Moderate (~18–20%) | Low–moderate (~6%) | Higher chitin | Good variety |
| Mealworm | Moderate (~18–20%) | High (~13%) | Hard chitin | Occasional treat |
| Superworm | Moderate (~18%) | High (~15%) | Hard head capsule | Occasional treat |
Discoids vs. dubia
Nearly interchangeable. Both are soft, high-protein, low-fat staples. Dubia breed faster and are sometimes cheaper and easier to find; discoids tend to run slightly leaner and are legal where dubia are restricted (Florida especially). Decide on legality and availability — either is excellent. (One note: some sources mix up the scientific names and call discoids Blaptica dubia — that's the dubia name. Discoids are Blaberus discoidalis.)
Discoids vs. crickets
Crickets are a fine variety feeder — leaner fat, decent protein — but they have a harder, higher-chitin exoskeleton that's tougher to digest, plus the familiar downsides: smell, chirping, escaping, short lifespan, and die-offs. As a staple, discoids win on digestibility and ease; crickets are great rotated in for diversity and to trigger the hunt.
Discoids vs. mealworms and superworms
This is where it's not close. Both mealworms (~13% fat, hard chitin) and superworms (~15% fat, hard head capsule) are high-fat treat feeders, not staples. Fed heavily they push a skink toward obesity and are harder to digest. Use them sparingly — superworms for an energy boost or a thin animal, mealworms as occasional variety — and never as the backbone of the diet.
Where silkworms and black soldier fly larvae fit
Two feeders worth knowing beyond the usual five, because they each do something discoids don't:
- Silkworms are soft, lean (low fat), and easy to digest — a genuinely good variety feeder for a skink, especially one that needs to slim down. The catch is they're delicate, expensive, and a hassle to keep (they only eat mulberry or commercial silkworm chow). Rotate them in; don't rely on them.
- Black soldier fly larvae (BSFL) are the one feeder that's actually calcium-rich — they're the exception to the "every feeder is phosphorus-heavy" rule because their bodies hold a naturally high calcium load. That makes them a smart addition to a skink's rotation specifically for bone health, though their small size and firm skin mean they supplement rather than replace a roach staple.
Neither displaces discoids as the everyday backbone, but both earn a spot in a well-rounded rotation — silkworms for a lean treat, BSFL for the calcium boost.
The risk of leaning too hard on any one feeder
Even a great staple becomes a problem if it's the only thing on the menu. Over-relying on discoids alone can leave gaps — no single feeder supplies the full spectrum of vitamins and minerals a skink needs, and the phosphorus-heavy profile of insects compounds if you never vary or supplement. The fix isn't to abandon discoids; it's to treat them as the dependable center of a rotation, surround them with variety (other insects, plus the plant matter skinks require), and always dust for calcium. Variety also guards against the occasional individual that develops a fixation or a sensitivity to one food, and it keeps feeding interesting enough to maintain a strong feeding response. A skink that eats discoids, the odd hornworm, a silkworm here, some BSFL there, and a steady base of greens and squash is far better insured than one fed roaches and nothing else.
Why discoids gut-load so well
A practical edge for skink keepers: discoids are outstanding at gut-loading. They have a large gut capacity, readily eat a wide range of foods (fruit, veg, grain, commercial gut-load), retain those nutrients well, and stay calm enough that they don't burn off their gut contents with stress before they're eaten. Load them for 24–48 hours on calcium-rich greens, carrot, and squash, and you deliver a genuinely nutrient-dense meal.
Building the actual diet
Insects are only one leg of a skink's diet. The full picture:
- Staple insect: discoids (or dubia), gut-loaded and calcium-dusted.
- Variety insects: rotate crickets, the occasional hornworm for hydration, silkworms for a lean option, and superworms/mealworms sparingly as treats.
- Plant matter: dark leafy greens (collards, mustard, dandelion), squash, carrot, zucchini, with fruit (berries, mango, papaya) in moderation for the sugar.
- Supplements: dust insects with calcium, alternating with a calcium-plus-D3 or multivitamin per your setup and UVB.
- Frequency: juveniles eat often (often daily) with more protein; adults take larger meals every 2–3 days with more plant matter. Watch body condition and stool and adjust.
When you want a clean, well-started staple colony or feeder-sized roaches, All Angles Creatures stocks healthy discoid roaches.
Reading your skink to tune the diet
The numbers in the table are a starting point, not a prescription — the skink tells you the rest. A few things I watch:
- Body condition. A healthy skink is full but not bloated, with no rolls of fat at the limbs and a tail that's firm but not bulging. Softening, widening, or fat deposits mean too much fat in the diet — cut the mealworms and superworms, lean harder on discoids and greens.
- Stool. Firm, formed droppings mean digestion is working; loose or undigested stool can signal too much chitin (over-relying on crickets or mealworms) or a sensitivity. Discoids' soft bodies are easy on the gut, which is one reason they suit sensitive eaters.
- Appetite and engagement. A skink that strikes eagerly at moving roaches is healthy and stimulated; a bored or stressed skink may need more variety or a feeding-response trigger like a hornworm.
- Growth rate in juveniles. Steady growth on frequent protein is the goal; stalled growth usually means not enough food or not enough warmth to digest it.
Adjust frequency, portion, and the protein-to-plant ratio off those signals rather than feeding to a fixed schedule forever. A growing juvenile and a mature adult are almost different animals nutritionally.
The short version
For a blue tongue skink, discoid roaches are a top-tier insect staple — high protein, moderate fat, soft and digestible, easy to keep, and legal where dubia aren't. Dubia tie them; crickets are good variety; mealworms and superworms are fatty treats only. Whatever you feed, dust with calcium (the "favorable ratio" claim is a myth), gut-load first, and build meals around the roach plus greens and rotation.
Wondering about fruit flies for skinks? See discoid roaches vs. fruit flies for blue tongue skinks, or the full feeder insect library.