Hornworms are a popular and easily accessible feeder for many reptiles. But can leopard geckos eat hornworms?
Although the answer is certainly yes, there are some surprising risks that accompany feeding hornworms to your leopard gecko.
This article will explore the pros and cons of offering hornworms to your leopard gecko, and will explain why you can consider them a wonderful treat for your leo, but not a staple feeder.
Can Leopard Geckos Eat Hornworms?
Yes! Leopard geckos can eat hornworms, but they ought to be given as an occasional treat, not as a staple feeder.
An important part of your leopard gecko’s diet is diversity.
That’s why you’re feeding it a variety of insects like Dubia roaches, crickets, and mealworms.
Another popular feeder for leopard geckos is hornworms.
Hornworms are large caterpillars that are readily available from most pet stores. They have decent nutritional value, and can be a nice change from your leo’s usual dinner fare.
But should hornworms be a regular staple in your leo’s diet? Let’s dig in and learn more.
What Are Hornworms?
Hornworm caterpillars are the larval stage of the moth family Sphingidae, commonly called “hawk” or “Sphynx” moths. They get the name “hornworm” from the hornlike projection at the end of their body.
They are sometimes also referred to as “Goliath caterpillars,” because they grow so rapidly from just a bit smaller than a quarter to roughly the size of a half dollar.
The most well-known hornworms in the United States are the tomato hornworm and the tobacco hornworm. Tomato hornworms can grow up to 3.9”, whereas tobacco hornworms tend to be a bit smaller at 2.7”.
If you have a garden and raise any sort of nightshade – like tomatoes, peppers, or potatoes – there’s a strong chance that you’ve come across these goliath caterpillars before.
Warning: Do not feed wild hornworms to your leopard gecko. Wild insects in general often carry pesticides to which they’ve developed immunity, and they frequently carry parasites. These can make your leo sick.
The Hornworm Life Cycle
There are four stages to the hornworm life cycle:
- Egg (early spring)
- Larva or caterpillar (summer – early fall)
- Pupa (early fall – winter)
- Adult or moth (early spring)
Hornworms mature quite rapidly – over the course of a single summer.
The eggs containing the hornworm hatch about a week after they’ve been laid in late spring. The hatched caterpillar then matures to its goliath size throughout the summer, pupating in early fall. The pupae then spend the winter under the soil and emerge in early spring as adult moths.
What Do Hornworms Eat?
Hornworms prefer to feast on plants of the Solanaceae, or nightshade, family. These include many garden variety vegetables such as:
- Sweet potatoes
Many exotic-looking flowers are members of the nightshade family, as is the well-known weed called “morning glory.”
Hornworm Nutritional Value
Believe it or not, leopard geckos eat hornworms in the wild. If you’re like most leopard gecko keepers, you probably enjoy offering your leo the kinds of insects it might find in the wild.
Hornworms are a great option because they’re made up of 84% moisture, making them quite juicy and much easier for your leo to swallow than a cricket or a Dubia roach. They’re also very slow, and therefore easier for young leopard geckos to catch.
But one of the main reasons you should consider occasionally feeding your leo hornworms are the health benefits they offer. These include:
- 9% protein
- 464 mg/kg calcium
- 1,394 mg/kg phosphorus
- 3% fat
While low in protein, hornworms are very high in calcium and, therefore, don’t need to be dusted prior to every feeding – although dusting is still recommended. Their high phosphorus content also helps prevent bone disease. And the fact that they are so low in fat means your leo can enjoy them without risk of obesity.
However, there are some downsides to feeding hornworms to your leopard gecko:
- The low protein content means that your leo will be hungry again quickly.
- They are relatively expensive, costing around $10 (US dollars) for just four on average.
- They are difficult to gut load since they prefer the sweet taste of nightshades.
- They can be addictive!
Feeding hornworms to your leopard gecko too often can lead to addiction. When a leopard gecko is addicted to hornworms, it will refuse to eat anything else. This will lead to malnutrition even if your leo is consuming multiple hornworms per week since the hornworm doesn’t provide all the nutrients your leo needs.
Pro Tip: Hornworms are like the fast-food of the lizard world. Offer to your leopard gecko sparingly – no more than once per week.
How to Feed Hornworms to Leopard Geckos
Hornworms are a common feeder for many different types of lizards and turtles. For this reason, they’re typically available at most pet stores (and even on Amazon!). Leopard geckos will usually refuse dead foods, so be sure to purchase and offer live hornworms for your leo.
Here are some basic age-appropriate guidelines for feeding hornworms to your leo:
- You can offer your baby leopard gecko small hornworms in moderate amounts, typically no more than two per week.
- When feeding your juvenile leopard gecko, you can offer it 1–3 small hornworms in a single meal.
- Your adult leopard gecko can have 3–4 hornworms per meal.
In addition to hornworms themselves, you can also feed your adult leo the pupae, so long as it is still small and soft. Once it hardens, however, it’s no longer good for food.
Warning: Do not feed a pupae to a baby or juvenile leopard gecko. They are at greater risk of choking than adult leopard geckos.
Wondering How to Breed Hornworms for Your Leopard Gecko?
Given the expense of purchasing hornworms to feed your leopard gecko, you may be considering starting your own colony. Perhaps you can even sell off your extras…
Be aware, however, that hornworms grow very quickly. Your little hornworms may be ½” one day, but grow to be between 3” and 4” in just a matter of weeks. This makes raising your own colony tricky because they can so quickly become too large for your leo to eat.
Most leopard gecko keepers prefer to just purchase hornworms as an occasional treat. If you choose to go this route, be sure to keep your cup of hornworms at temperatures between 55ºF and 60ºF to slow their growth.
Takeaway: Hornworms make excellent treats for your leopard gecko. However, because of the risk of addiction, they should not be a staple in your leopard gecko’s diet. Stick with insects like Dubia roaches and crickets, supplementing with the occasional hornworm.
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