Feeder Insect Nutrition
Feeder insects aren't nutritionally interchangeable.
Species matters. Life stage matters. What the insect has been eating matters. Even the way nutritional data is measured can dramatically change the numbers you see on a chart.
That's why our Nutrition Guides don't reduce each feeder to a protein percentage and call it finished.
We looked at published research on the feeder insects we raise — crickets, discoid roaches, mealworms, superworms and hornworms — to understand what the available evidence actually tells us, where studies disagree, and where reliable data simply doesn't exist.
Five feeders. Five different nutritional roles.
Active, widely used staple feeders. We raise the banded cricket, Gryllodes sigillatus, one of the better-documented feeder insects. Dry-matter figures from a 2023 analysis, with a note on why the reported protein percentage depends on the calculation method.
A substantial staple feeder with meaningful differences between life stages. Available research indicates adult feeder roaches tend to be higher in protein and lower in fat than subadults. Species-specific published data for Blaberus discoidalis, however, remains limited.
Convenient, easy to portion and useful as part of a varied diet. Their nutritional composition can vary considerably with rearing conditions, particularly fat and calcium, which is one reason a single headline number does not tell the whole story.
An energy-dense larva, and a different species from the mealworm rather than an oversized version of one. Published analyses place superworm fat well above mealworm fat, which is worth weighing when deciding how often they are offered.
Soft-bodied feeders notable above all for their very high moisture content, approximately 85% in the available data. Published analysis for commercially raised Manduca sexta is much thinner than for the others, and we say so rather than filling the gaps with numbers.
As-fed and dry matter are not the same thing
This distinction matters.
As-fed values describe the insect as your reptile actually eats it, including its water.
Dry-matter values remove the water mathematically so researchers can compare the nutrients contained in the remaining material.
That means a feeder listed at 20% protein as-fed cannot be directly compared with another listed at 60% protein on a dry-matter basis. Both figures can be accurate while describing different things.
Every nutritional figure we publish identifies its basis so you know what you're actually looking at.
Does feeder size change nutrition?
Sometimes — but not in a way that allows us to assign a different nutrition label to every size we sell.
Research shows meaningful nutritional changes between some insect life stages. Adult crickets, for example, differ from nymphs, and adult feeder roaches can differ substantially from subadults.
What the published research does not give us is a reliable nutritional analysis for every commercial size such as 1/8″, 1/4″, 1/2″ or 3/4″.
Where life-stage data exist, our guides show them.
Where they don't, we don't invent them.
Why calcium needs special attention
Most commonly used feeder insects naturally contain substantially more phosphorus than calcium.
That's not necessarily evidence that the insects were poorly raised. Insects lack a mineralized skeleton, so their bodies naturally contain relatively little calcium, while phosphorus is abundant in their tissues.
That's why calcium supplementation is an important part of insectivore husbandry — and why gut loading and dusting deserve their own explanation rather than being treated as marketing terms.
Explore: Gut Loading Feeder Insects →
What the feeder ate matters, too
A feeder doesn't arrive nutritionally empty and suddenly become food when your reptile catches it.
Gut contents can account for approximately 4–7% of an insect's live weight, and research shows that rearing diet can materially affect measured nutritional composition.
That's one reason we pay attention to our colony diets and why our feeders receive appropriate dry diets along with fresh foods such as leafy greens, vegetables and squash.
But fresh-fed and gut-loaded aren't synonyms.
A vegetable-fed insect has eaten fresh food. A properly calcium gut-loaded insect has been fed a specifically formulated, sufficiently high-calcium diet for the purpose of increasing the calcium it carries when consumed.
Those are different processes, and our guides keep them separate.
Nutrition is more than a number
Laboratory values vary with species, life stage, diet, gut contents, rearing conditions and analytical method. Even two legitimate analyses of the same feeder can produce substantially different results.
So throughout these guides you'll see:
Ranges when the research gives ranges. Life stages when they're known. As-fed and dry-matter values clearly identified. Limitations where the evidence is limited. And no precision we can't support.
Because knowing what isn't known is part of understanding nutrition, too.
Explore the Nutrition Guides
Cricket Nutrition Guide →
Discoid Roach Nutrition Guide →
Mealworm Nutrition Guide →
Superworm Nutrition Guide →
Hornworm Nutrition Guide →
Gut Loading Feeder Insects →
Raised for Reptiles. By People Who Keep Them.