Ultimate Hornworm Care

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.

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

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.

Where Are Hornworms From?

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

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. 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.