Raising Hornworms: The Ultimate Care & Maintenance Guide

When it comes to providing your reptile with the best feeder insects, we have a great recommendation for you: the hornworm. Care is not only simple, but raising hornworms also requires very little maintenance. There are many types of vegetables that can be used as hornworm food. But what if you don’t know anything about this unique feeder insect? Don’t worry — we’re here to help. To review hornworm care, we’ll go over some common facts to help you understand questions like “What do hornworms turn into?” “How do I raise hornworms?” “How do I house hornworms?” and more.

What is a Hornworm? (Hawk Moths)

Before you consider practicing hornworm care at home, you should know that the main species have two scientific names: Manduca quinquemaculata and Manduca sexta. While they are harmless to humans, hornworms are well-known pests throughout their native US. Luckily, they have not reached the point of causing significant economic damage to crops across the country and are typically only a problem for hobbyists or small-space gardeners. For example, this insect is also known as a “tomato hornworm.” As the name suggests, tomatoes are a common hornworm food, but these hefty bugs will also feed on other vegetables in the nightshade family, including eggplants, peppers and potatoes. In one year, there may be two generations to pass through one crop.

Hornworm eggs are crucial in the life cycle of hornworms, marking the beginning of their development. Raising hornworms includes obtaining these eggs, setting up an appropriate habitat, and ensuring ideal conditions for their growth and eventual pupation.

Hornworms include various species of caterpillars that can reach lengths of up to 4” long. Depending on the species, the hornworm’s body may be white to yellow with no markings, or a beautiful, rich green with intricate designs decorating their sides. Generally, more mature caterpillars in both species can be green with eight V-shaped, white marks with gray and black circles nestled into the point of the white V.

Hornworms get their name from the large horn on the end of their tails, which are typically black or red and used as a formidable defense against predatory species. If it feels it must defend itself, the hornworm will lift its backside and wave its horn from side to side. Surprisingly, though, this isn’t always their first line of defense. Hornworms, when threatened, will rear up on the posterior half of their bodies in a defensive display (and, from personal experience, it’s quite startling!).

Raising hornworms can be a challenge because they are some of the largest known caterpillars and can weigh up to 0.35 oz (for a larval stage, that’s quite heavy)! These insects, like many species’ larvae, are specialized herbivores, feeding on the leaves of the nightshades mentioned above. Because of how much food they take in (some feed non-stop throughout both day and night), their digestive system comprises more than 50% of their body. Normally, they only stop feeding when they molt as they grow through their immature life stages. Under the right environmental conditions, hornworms may reach up to 10,000 times their original weight in as little as two weeks, making hornworm care extra taxing.

Because the hornworm is not its own distinct species, one question we get from hobbyists is “what do hornworms turn into?” Despite their size, these insects are actually in the juvenile stage of growth and become hummingbird moths, which are also known as sphinx moths or hawk moths (other species’ names are tobacco hornworm and goliath worm). These are bulky insects with relatively narrow front wings – and very large with a wingspan of 4-5 inches. They may also be some of the cutest insects of the currently known moth species, with their short, fuzzy bodies and fluffy antennae that stretch far out from their faces. Even in this adult stage, the hornworm is quite aesthetically pleasing, still being covered in designs of gray, brown, black, green, red or yellow.

As adults, leaves are no longer hornworm food. Instead, these bugs drink the nectar of flowers using their 14” long proboscis (this is what gives them the name “hummingbird moth”). The long proboscis allows the moths to reach deep into the corollas of flowers, enabling the insect to feed on flowers that even butterflies and bees cannot reach. This moth is a fast and powerful flier and has many other stunning features. During flight, they maintain a body temperature of nearly 100°F, which is quite high for such an insect. That said, when it is cold outside, moths may prepare for flight by vibrating their flight muscles as a way to build up heat before they take off. This is a form of thermoregulation, another trait that sets these moths apart from many other insect species.

Life Cycle of Hornworms: From Hornworm Eggs to Adults

If you came to this page wondering “what does a hornworm turn into?” we’re happy to explain. The hornworm, just like all other moths, goes through a complete metamorphosis as it matures. This means that each life stage preceding the adult moth is unrecognizable and physiologically distinct from each other. There are four stages of this insect’s life cycle that you should be aware of when practicing hornworm care: the egg (also known as the “ova”), larvae, pupa and adult.

Egg

After emerging in the spring, the adult moths mate and each female deposits their smooth, light green eggs – each about 0.04” in length – individually upon the upper and lower surfaces of solanaceous (nightshades) plants’ leaves. This is done at night, presumably so the eggs do not desiccate as they are freshly laid. The eggs are quite beautiful to look at, having a pearly sheen about them in addition to the yellow-green or light green coloring.

Larva (Caterpillar)

Once hatched, the larvae do not leave the leaf they were deposited on. Instead, they stay on the leaf and feed on its tissue as they grow into the following larval stages, known as “instars.” As they grow, the larvae move throughout this original host plant until they reach the fifth instar (the “caterpillar”). If necessary, they are entirely capable of migrating to another host plant. Otherwise, they risk wasting precious energy stores and may die if they move to a less nutritious source. As larvae, they are incredibly well camouflaged on the leaves of nightshades, making them difficult for even the most attentive gardener to spot. The entire larval stage, which is composed of 5 or 6 instars, takes about 3-4 weeks.

Pupa

When they are ready to pupate, the larvae will drop off of their host plant and burrow into the soil below. Hornworm pupae are different in appearance to the caterpillar. Instead of a rich green with beautiful decorations, pupae darken to a deep reddish-brown and have a loop at the anterior end (this becomes the mouthparts of the adult moth). The pupae remain in the soil for a few weeks until they are ready to emerge as adult moths. It is crucial to maintain proper moisture levels and monitor the pupating hornworms to ensure successful transformation.

Adult

During the spring, the adult moths begin to emerge from the soil in their final, beautiful form. They may be patterned in the many striking colors mentioned above and are relatively heavy and large for moths. During their adult lives, they focus primarily on mating and reproduction. Keeping a few hornworms to allow them to pupate and transform into moths can be a fascinating process to observe.

Where Are Hornworms From? (Tomato Plants)

Raising hornworms is significantly easier to do in the United States. As we mentioned before, hornworms are native to America. In fact, there are approximately 120 species that inhabit many states across the country, although you'll find them mostly distributed throughout the Northern states. However, there are more than 1200 known species of hornworms throughout the world, with high levels of diversity in tropical regions.

Nutritional Value of Hornworms as Feeder Insects

Hornworm care can make for great feeder insects to give to your beloved reptile. Since they have no hard exoskeleton, using hornworms as food is great for animals that may have difficulty digesting meals, especially younger reptiles that are just getting the hang of feeding. They also provide a great deal of moisture for any reptile that may be suffering from dehydration.

Raising Hornworms

Raising hornworms is relatively easy compared to taking care of other feeder insects. Given that they exist mostly in human-dominated landscapes, such as farms and home gardens, they are not too demanding in captivity and can be easily satiated with foods you already have readily available. Breeding hornworms at home can save costs and ensure a fresh, nutritious food source for your pets. Still, it is not recommended that you just pick up any old hornworm from outside your house, as you cannot be sure of what diseases it may harbor. Instead, order hornworms from a reputable breeder to ensure the highest quality feeder for your reptile. Below are some guidelines to help you get started with raising hornworms.

1. Housing Your Hornworms

When you order your hornworms, they will arrive in a plastic cup with only a little bit of substrate covering the bottom of the cup. Although the larvae can persist in this container for several days, you should separate each larva into individual containers, such as a plastic storage container, as soon as you can. This is to ensure the best, healthiest growth rates for each of them as you will be protecting them from competing for food. Do this carefully, though! Hornworm care requires a delicate hand since they are so soft and lack the chitinous outer covering that many other feeder insects have, meaning they can be more easily damaged during handling.

Once separated, place each hornworm into its own vial with a pre-made, artificial diet. You can use kitchen scraps as hornworm food, but due to the moisture content of the types of vegetables they eat (and, therefore, their propensity to rot quickly), it may be in your best interest to mostly offer dry food. Prepare and store hornworm chow to ensure it is fresh and accessible for the growing worms.

2. Maintenance

When raising hornworms, you must provide them with a constant light source to keep them happy and healthy. Make sure the temperature is roughly 81°F and never allow their containers to get too close to, or surpass, 90°F as this will surely kill them. Feed them once a day with your artificial feed and they will remain healthy and nutritious for your lizard or turtle!

Using a hornworm as food is a great idea because these insects are a highly nutritious supplement for your reptile. They are packed with moisture, which is great for any animals that may struggle with their water intake. They’re also a great snack for picky eaters and are incredibly easy to find and raise. This beautiful insect can be a unique addition to your reptile’s diet, and a rewarding critter to maintain. For adult moths, use a hummingbird feeder filled with hummingbird food to ensure they receive the necessary nutrition. Additionally, a tomato plant is essential for breeding hornworms as it provides a suitable environment for egg-laying.

Find Great Feeder Insects at Topflight Dubia

Hornworm care is relatively easy, and they make excellent feeder insects — as do nutritious Dubia roaches. That’s where we can help. Topflight Dubia specializes in breeding and selling top-quality Dubia roaches that are sure to bring out the best in your reptilian friends. Available in or 1/4” - 3/8” sizes, you can buy these roaches in bulk to save yourself money in the long-run when feeding your pet. Order today!