Feeder Insect Nutrition: Crickets, Dubia Roaches & Mealworms Compared

For insectivorous reptiles, the staple diet is a nutrition arithmetic problem: water, protein, fat, calcium-to-phosphorus ratio — every feeder insect has a different profile. Feeding only one insect forever is like living on white rice: you survive, but malnutrition shows up sooner or later. This article compares the most common feeders and gives you the pairing rules.

1. The four numbers that matter

When comparing feeders, watch four numbers: moisture (hydration and satiety), protein (the main growth material), fat (energy; too much causes obesity), and calcium-to-phosphorus ratio (ideal ≥1:1; most insects sit at 1:5 to 1:10 — which is exactly why you must dust calcium). There is no perfect insect, only the right combination.

2. Crickets: the reliable all-rounder

Crickets are the traditional staple: roughly 18–21% protein, about 70% water, great palatability, and accepted by nearly every insectivore. Their drawbacks: a low calcium-to-phosphorus ratio (about 1:7), fiddly to keep (noise, escapes, die fast), and a small parasite risk — buy from captive-bred suppliers. A tub of small crickets a week is standard practice for one gecko.

3. Dubia roaches: the value champion

Dubia roaches have become the first choice of experienced keepers: about 20–23% protein, moderate fat, a relatively good calcium ratio for an insect, and they do not fly, chirp, escape easily, or die quickly, and they store well. The downsides: slightly higher unit cost, need a heated colony, and some people cannot stand roaches. For nutrition plus low hassle, dubias are the best "permanent staple."

4. Mealworms and superworms: the fat trap

Mealworms are about 13% fat; superworms top 20% — both are "fatty treats," not staples. Occasional feeding is fine; a gecko fed only mealworms long-term is almost guaranteed to become obese, picky and then food-refusing. They are also high in chitin, so juveniles fed too many can struggle to digest. Keep them under 20–30% of the total diet.

5. Waxworms, fruit flies and others

Waxworms are over 25% fat — the classic "fattening treat" for underweight individuals or as a reward, at most once a week. Fruit flies are the critical first food for crested gecko hatchlings, small anoles and other small juveniles. Earthworms are high in water and low in protein — suited to aquatic turtles and some frogs, not terrestrial geckos. Pinkies and adult rodents are prey exclusively for snakes and are outside the insect discussion.

6. Pairing rules and the gut-loading law

A recommended daily mix: staple (crickets or dubias) 70–80%, secondary (mealworms etc.) 10–20%, treats (waxworms) no more than 5–10%, adjusted by species and size. But more important than the mix is a step almost everyone skips — gut-loading: 24–48 hours before feeding, give the insects a high-calcium, high-vitamin diet (commercial gut-load food, carrots, leafy greens, citrus). The insects fill themselves with nutrition, so what your pet swallows is not just protein but calcium and vitamins too.

And always finish with dusting: whichever insect you serve, shake it in the calcium powder jar so the surface is coated. The feeders' calcium-to-phosphorus ratio decides it — skip the dusting and you have skipped the calcium.

There is no "best feeder insect" — only the best combination. Rotate staples + gut-load + dust calcium, and you have solved nine-tenths of nutrition problems.