What Do Caterpillars Eat? – Nature’s Most Voracious Eaters

Caterpillars, with their wiggly ways and curious patterns have always fascinated us. But have you ever stopped to think about what they eat? They can destroy your garden if you’re not careful, laying waste to your efforts, but are they all herbivores? Does their diet change as they develop? And how important are caterpillars in their ecosystem and the food chain? Let’s take a look!

What Do Caterpillars Eat Exactly?

Caterpillars, for the most part are herbivorous. They primarily feast on plant material. But, just like humans have favourite foods, caterpillars can be picky eaters too. Their preferences change depending on the species and some have very specific diets. For instance, silkworms are very restrictive, mostly munching on Mulberry leaves (which are their favourite) as well as the leaves of some vegetables – notably beetroot, carrot and iceberg lettuce.

While most caterpillars are content with leaves, some venture out and explore flowers, fruits, and even other surprising foods. It really does depend on the species though.

How Does It Vary By Region And Species?

Caterpillars are found all over the world, and their diet can vary widely based on where they live and their specific species. In tropical rainforests, caterpillars might munch on a variety of lush plants, while those in deserts naturally have a more limited menu.

Some caterpillars have evolved to eat specific plants, making them specialists, while others are generalists, eating a variety of plants. Most though, are capable of eating only a handful of different types of plant.

They are usually capable of eating only native species to their natural environment, though there are exceptions to this rule.

Are All Caterpillars Herbivores?

While the majority of caterpillars are herbivores, some are known to be less picky. There are caterpillars that have evolved to be carnivorous, preying on aphids and other small insects.

The large blue caterpillar is one of the scariest examples of how deceitful and gluttonous a caterpillar can be. They start off eating vegetation, particularly from Wild Thyme or Marjoram plants, before dropping to the ground. Then the young caterpillars will deceive their ant neighbours (specifically Myrmica Sabuleti – red ants) into believing they are one of their own infants that have made their way out of the nest.

They will then carry the con artist caterpillar back to what they think is the safety of their nest. The blue caterpillar will then proceed to devour the ant eggs in a buffet that will last for months over winter, into spring until they form their chrysalis.

It sounds awful, for the ants at least but believe it or not, some caterpillars even resort to cannibalism when food is scarce, eating their own and other species quite happily.

A Table Of The Foods That Caterpillars Eat

What Do Baby Caterpillars Eat?

Baby caterpillars, or larvae, are just like the bigger ones but need softer, juicier foods. They’re in their early growing phase, so they eat almost constantly. They start eating when they are still in their shell, working their way out into the world. Then when they first hatch, they eat the rest of their eggshell as their first meal, before moving on to eating the plant on which they hatched!

As they grow, they’ll move on to the plants around them, munching away to fuel their rapid growth. They have exceptional appetites, as their whole existence revolves around growing and gathering enough energy to support their transition through their chrysalis phase into their mature butterfly or moth form. They don’t drink water directly, rather they get the fluid they need from the food they eat.

How Do Caterpillars Eat?

Caterpillars don’t have any teeth precisely, but instead they have strong jaws called mandibles. They use these to chomp down on leaves, making their way from the edge inward. Their mandible jaws work side-to-side, rather than the up-down, horizontal motion that we are familiar with in the human jaw.

If you’ve ever seen holes in leaves or patterns that look like a maze, you’ve seen caterpillar handiwork! They have a voracious appetite and can consume large amounts of food in a short time.

How Much Do Caterpillars Eat?

These tiny creatures have BIG appetites! Some caterpillars can eat up to several times their body weight in a single day. This rapid eating supports their fast growth. In some cases, a caterpillar might increase its body size by over 1000 times from when it hatches to when it pupates.

Many species remain a caterpillar for only a few weeks until they form their chrysalis. So they need the energy to grow quickly and prepare for their transformation. Some other species, particularly larger ones, remain as a caterpillar for months before transforming. In some cases, such as the large blue butterfly, the caterpillar stage is far longer (several months) than the butterfly stage, which may only last for few weeks.

After Changing Into Moths And Butterflies, Do They Eat The Same Food?

After their transformation, their diet changes drastically. Some butterflies eat or sip nectar from flowers using their long, straw-like proboscis. Many moths eat the same. They no longer have the chewing mandibles they had as caterpillars. So, no more leaf munching for them! Some moths don’t eat at all, having a lifespan of only a few days in their adult form.

But wait, do moths not eat clothes? I’ve always been told they were responsible for the little holes that appear on clothes in my wardrobe! No, moths don’t eat clothes. But they do lay eggs, and when those eggs hatch into larvae, these will eat fabric like wool, cotton and silk. So it’s not the moth itself, but the eggs that they lay that are responsible for munching on the closes in your closet!

Importance of Caterpillars in the Ecosystem

Caterpillars are little heroes of our ecosystem. Think of them as one of nature’s gardeners; they munch on plants, many of them undesirable or weeds, keeping them in check. Plus, they’re important to the foodchain – a favourite snack for many animals, from birds to tiny insects.

When they transform into butterflies or moths, they help flowers by spreading pollen. So, when you spot a caterpillar or a butterfly, it’s a little sign that our environment is doing well. But if they start to disappear, it’s Mother Nature’s way of telling us something’s off balance.

Threats to Caterpillars

There are lots of animals and insects that eat caterpillars. They face threats from birds, spiders, and even other caterpillars that see them as a tasty treat. Nocturnal hunters in particular are fond of eating moths, particularly bats, owls and web-weaving spiders. Additionally, human-made threats like pesticides can be deadly to them.

Some caterpillars, especially some green caterpillars, have developed amazing defence mechanisms, like bright warning colours or mimicking other animals, to ward off predators. Some caterpillars are poisonous as their primary method of defence.

It is a common practice to introduce natural predators of caterpillars in areas of agriculture or managed gardens, as a safe way to contain populations and protect the vegetables or plants. Some people will introduce specific ground beetles that will eat the caterpillars, removing the threat without adding toxins to your plants. Encouraging garden birds is also a popular method of control.

While these methods do nothing to encourage and protect caterpillar numbers, they are methods of control with the least environmental impact.

What Foods Are Toxic To Caterpillars?

While caterpillars are adaptable eaters, they’re sensitive to chemicals. Pesticides and insecticides are harmful and can be lethal. Some plants also produce toxins as a defence mechanism, which can deter caterpillars from eating them.

For the most part though, caterpillars will stick to specific plants that are native to their environment, and each will have their own range of plants that they generally eat. They are unlikely to eat any toxic plants they are not familiar with. As such, the greatest threat from toxic food, comes from plants that they commonly consume being sprayed with pesticides.

How To Feed Pet Caterpillars

If you’re raising caterpillars at home, it’s essential to provide them with fresh, pesticide-free leaves from the plant you found them on. Ensure they have a moist environment, but not too wet, and remove old wilted leaves regularly.

How To Protect Your Yard Or Garden From Caterpillars?

Caterpillars, with their huge appetites are capable of destroying many of the plants you have in your garden in a matter of days. If you’re trying to protect your plants, consider using natural repellents or introducing beneficial insects that prey on caterpillars. Another method is to plant decoy plants that caterpillars prefer, drawing them away from your main ‘display’ plants, or veg patch.

5 Fun Caterpillar Diet Facts For Kids

• Some caterpillars trick ants into taking them home, then once in their colony, the will snack on the ant babies!
• The Lunar Hornet Moth caterpillar dines inside trees for up to two whole years!
• The Rosy Marbled moth caterpillar is a notorious omnivore, eating both plants and bugs.
• Some caterpillars have a sweet tooth and love munching on honeycomb.
• Caterpillars can be herbivores, omnivores or carnivores. It depends on the species, and on their available food sources.

Classification Table