Giant Mealworms: Can You Feed Them To Leopard Geckos?

can leopard geckos eat giant mealworms?

Every leopard gecko loves mealworms – and with giant mealworms, there’s even more to love! But if giant mealworms are new to you, you might be wondering what exactly they are, and how they differ from your leo’s regular insect menu.

Giant mealworms are an exceptionally nutritious food choice for adult leopard geckos. They are high in protein, and can be gut loaded or dusted to increase specific nutrients. However, they should not be fed to juveniles because of their size.

Read on to learn more about these insects, and the best practices to follow when feeding them to your leopard gecko. 

Giant Mealworms: A Safe Diet Choice For Leopard Geckos

Giant mealworms are Tenebrio molitor larvae that have been hormonally treated in the pre-pupal stage.

They differ from regular mealworms in that they never mature into adult T. molitor or yellow mealworm beetles. Instead, they grow to large sizes, reaching up to 3.8 cm and weighing 300 mg. 

They have high protein and meat content and can be fed to adult leopard geckos. Studies have shown that leopard geckos fed on a diet of mealworms grow bigger than those fed a mixed diet or on crickets only. 

MealwormGiant mealwormSuperworm
Size (cms)1 – 1.82.5 – 3.83.8 – 6
Protein (mg/g)187184197
Fat (mg/g)134168177
Moisture (mg/g)619610579
Dietary fiber27111
Metabolizable energy (cal/g)205622522423
Calcium (mg/kg)196184177
Phosphorus (mg/kg)272023702850
StorageCan be refrigeratedCan be refrigeratedCannot be refrigerated
SafetySafe for feeding to leopard geckosSafe for feeding to adult leopard geckosCan bite and wound leopard geckos
Table: Comparison of nutrient value of giant mealworms with other feeder insects. Adapted from Finke, 2002.

Giant mealworms differ from other larval diets such as regular mealworms (in size) and from superworms (in nutritive content and size).

Superworms are 5 times larger than giant mealworms. They are rich in calcium, but are higher in fat than giant mealworms and contain slightly lower protein levels. This makes giant mealworms the healthier choice. 

Superworms can also harm your gecko by biting or stinging it. Giant mealworms, on the other hand, cause no wounds at all.

In addition, giant mealworms can be refrigerated, whereas other feeder insects cannot. Their easy storage and higher meat content make them a great dietary choice for your pet leopard gecko. 

Ideally, leopard geckos should only be fed live food since dead insects do not have the same amount of nutrients. Read more about feeding mealworms to your gecko here.

Precautions For Feeding Your Leopard Gecko Giant Mealworms

Though giant mealworms are a safe food for leopard geckos, care should be taken under the following circumstances:

  • Baby leopard geckos may not be able to ingest giant mealworms, and should instead be fed with regular, smaller mealworms (6-8 mealworms) every day;
  • Adolescent or juvenile geckos, likewise, must be fed preferably with other insect diets, such as crickets or yellow mealworms (8-10 mealworms), every other day, to avoid impaction;
  • Mature adult geckos can be given giant mealworms (6-9 giant mealworms), 2-3 times a week. Pay attention to the relative size of the insect. 

As a rule of thumb, geckos can be fed with food no larger than the space between their eyes. Anything larger can cause harm to your gecko through impaction.

It’s a good idea to include the same quantities of regular food (like crickets) in your leopard gecko’s diet, and alternate it with regular mealworms or giant mealworms. Read about what to do if your gecko is refusing to eat mealworms here.

how many giant mealworms can I feed my leopard gecko?
Mealworm sizes vary, but giant mealworms are way bigger than the normal ones.

Building Your Leopard Gecko’s Giant Mealworm Diet Routine From Scratch

Now that we know the basics of feeding giant mealworms to your gecko, we can dig deeper into the steps you need to take when incorporating them into its dietary routine.

Where Can You Find Giant Mealworms?

Giant mealworms are available in pet stores, and can also be purchased online. Make sure that your mealworms are alive, and keep them refrigerated when necessary, to both prolong shelf-life and arrest their development at the larval stage. 

Some pet stores where you can find well-fed and healthy giant mealworms are Josh’s Frogs live feeder store, Northampton Reptile Center, and Rainbow Mealworms

Once you have your giant mealworms, you can keep them alive for 30 days without refrigeration, so make sure to order new stock each month. 

Preparing Giant Mealworms For Feeding Your Leopard Gecko

Leopard geckos cannot directly feed on vegetables or fruits, since, unlike other geckos, they do not have the capacity to digest plant matter. Therefore, to replenish and increase the gecko’s nutrition intake, giant mealworms can be gut-loaded or dusted. 

Gut loading giant mealworms

Gut-loading is when giant mealworms are ‘plumped’ up prior to feeding them to your pet so that they can pass on the vitamins and minerals they fed on to the gecko.

This is done by first cleaning them off the packing material they arrive in and putting them in a container with feed such as a thin slice of carrot. 

The fully-fed giant mealworms can then be placed in the same tank as your leopard gecko, 12 hours after they’ve been gut-loaded.

Dusting giant mealworms

Dusting is done when your gecko isn’t getting enough vitamins or minerals.

A fine supplement powder, such as calcium dust, can be added to your container of giant mealworms, after spraying them with a fine mist of water so that the dust will stick to them. 

After dusting, the giant mealworms can be immediately fed to your pet, to avoid the vitamin dust rubbing off.

Leaving Giant Mealworms In Your Gecko’s Tank

If you’re unable to schedule a feeding time for your pet during the workday, you can leave giant mealworms in the same tank as your gecko.

Make sure to include a few slices of carrots in the tank, so that the mealworms can feed on them and will be sufficiently gut-loaded by the time your gecko eats them. 

Final Thoughts

Giant mealworms are great insect feeders for your leopard gecko, due to their balanced nutritive value and higher meat content.

They can be stored easily, and fed to your pet with minimal supplementation. Gut-loading and dusting them are simple steps that can be followed prior to feeding them to your leopard gecko to increase their nutritional value.

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