This is the guide on this site with the largest gap between what people expect and what is true. Turtles and tortoises are lumped together constantly, and for feeding purposes they are not the same animal at all. Some of them eat feeder insects as a normal part of the diet. Others should never be given one. This guide separates the three groups, says which feeders suit each, and is direct about the group we cannot sell anything useful to. It is general husbandry rather than veterinary advice.
Three groups, three different answers
| Group | Examples | Do feeder insects belong in the diet? |
|---|---|---|
| Tortoises | Sulcata, Hermann's, Russian, leopard, Greek | No. These are herbivores. Insects are not part of the diet. |
| Box turtles | Eastern, three-toed, ornate | Yes. Omnivores. Heavily so when young, less so as adults. |
| Aquatic and semi-aquatic turtles | Red-eared sliders, painted turtles, musk turtles, map turtles | Yes, as part of the animal-protein share. Juveniles more than adults. |
Everything below follows from that split.
Tortoises: do not feed them insects
The Merck Veterinary Manual is unambiguous: tortoises are herbivorous and must consume plant material to maintain healthy gut physiology. Their digestive system runs on microbial fermentation of plant fiber. A tortoise diet is grasses, weeds, leaves and flowers, with the specifics varying by species and by where the animal comes from.
The reason this matters commercially is that people do buy insects for tortoises, usually because a tortoise ate one and seemed fine. Merck notes that shell deformities in tortoises have been thought to result from rapid growth associated with high-protein diets. Excess dietary protein is a recognized concern in this group, and the damage is slow and structural rather than acute.
If you keep a tortoise, nothing we sell belongs in its diet. We would rather say that than sell you a tub of feeders for an animal that has no use for them.
Box turtles: insects genuinely belong, in the right proportion
Box turtles are the group that most resembles what people picture when they imagine feeding a turtle. They are omnivores, and the balance shifts with age. Published guidance describes young box turtles, up to roughly four to six years old, as primarily carnivorous, with adults becoming largely herbivorous and taking protein in smaller amounts.
That gives two different feeding patterns from the same animal:
- Growing box turtles. A substantial animal-protein share. This is where crickets, roaches and earthworms do real work. We do not sell crickets or earthworms. Dubia roaches are what we sell instead.
- Adult box turtles. Mostly plant matter, with insects offered as an occasional item rather than a daily one. Earthworms, mealworms, waxworms and moth larvae are all named in veterinary guidance as protein sources for this group.
Earthworms deserve a mention on their own. Merck notes that most invertebrates do not carry the calcium-to-phosphorus ratio needed to support healthy bone growth in reptiles and amphibians, and names earthworms as the exception. For a shelled animal building bone continuously, that is not a small point.
Aquatic turtles: insects are one part of a mixed diet
Sliders, painted turtles and their relatives are omnivores whose diet changes with age in the same direction. VCA's guidance is that the carnivorous portion should be no more than about two thirds of the diet for juveniles and about half for adults, with the rest plant matter.
In practice most keepers build the diet around a good commercial aquatic turtle pellet and then add to it. Feeder insects are part of what goes on top. Crickets, roaches, mealworms, waxworms and earthworms are all listed in veterinary guidance as suitable, alongside snails and slugs.
The fish problem
Feeder fish are the part of aquatic turtle feeding most worth being careful about. VCA raises two separate issues: a fish-heavy diet risks thiamine deficiency, so fish should stay a small part of the diet, and live feeder fish have been implicated as carriers of parasites and bacteria. Oily fish such as smelt and mackerel are also flagged for their fat content. Feeder insects are a cleaner way to deliver the same animal protein.
Feeding in water
Aquatic turtles swallow in water and generally have to eat in it. That has a practical consequence for feeder choice: anything that floats away, sinks into gravel or dissolves quickly makes a mess and fouls the water. Uneaten food should be out within a day. Many keepers feed in a separate container for exactly this reason.
Sizing, and how much
Turtles are less prone to the sizing errors that catch lizard keepers, because they bite pieces off rather than swallowing prey whole. The constraints are different:
- Match the feeder to the turtle's mouth rather than to a formula. A hatchling slider and an adult box turtle are not in the same range.
- Portion matters more than size. Overfeeding is the standard problem in captive turtles, and obesity in this group is common.
- Frequency changes with age. Published guidance has juveniles eating daily and adults every two to three days.
- Remove what is not eaten. Within about a day for aquatic setups.
Because size grading is not standardized between suppliers, the dubia roach size chart gives the length in inches behind each dubia size name if you want to match a feeder to a specific animal rather than guess.
Supplements and what to avoid
Feeder insects are calcium-poor relative to phosphorus, and a shelled animal needs calcium continuously. Gut loading and dusting apply here as they do everywhere else, and calcium blocks or cuttlebone left available are commonly recommended for turtles. Frequency is a question for a vet, because it interacts with lighting and with the rest of the diet.
What to keep out:
- Insects for tortoises. Covered above.
- Wild-caught insects. Pesticide residue and parasites.
- Fireflies. Cardiotoxic. Cornell University biologists warned in 1999 that fireflies were killing zoo and pet lizards. Not worth the risk here either.
- Iceberg lettuce. Not harmful, just close to nutritionally empty, and it displaces food that is not.
- A protein-heavy diet in any of these animals past the growth stage. This is the most common long-term feeding error in the group.
For the comparative figures behind these choices, the nutrition table in our bearded dragon feeder guide puts moisture, protein, fat and calcium-to-phosphorus ratio side by side across feeder species, with sources. The guide on gut loading feeder insects covers what to feed the insects first.
Ordering, and where to go next
The practical shape of an order for a turtle keeper is small and regular rather than large and occasional, because insects are a component of the diet rather than the whole of it. An adult box turtle taking insects a couple of times a week gets through very little, and buying at bulk quantities means storing feeders for weeks.
The exception is a growing box turtle or a juvenile slider, which will get through a meaningful quantity of insects during the carnivorous phase. That phase lasts years rather than months, so it is worth setting up properly rather than buying ad hoc.
For box turtles and aquatic turtles, we sell dubia roaches, mealworms and waxworms, all in the feeders collection. When a box lands, what to do when your feeders arrive covers the unpacking.
This guide describes feeding healthy animals. Shell deformity, a soft shell, swollen eyes, or a turtle that has stopped eating are veterinary problems, and chronic nutritional disease is common enough in captive chelonians that it is worth taking seriously early.