North Carolina is home to nearly 3,000 species of caterpillars. Before you grab the pitchforks and pesticides, consider that only about 3% of caterpillars are garden pests. Not to mention that caterpillars are baby butterflies and moths, and who doesn’t want more beautiful butterflies in their garden!
Caterpillars are the larva stage of the butterfly or moth life cycle, and their one job is to eat, eat, eat. If you’ve ever thought to yourself that caterpillars really love munching on a particular plant (or plants) in your garden, you’re not imagining things. Caterpillars often rely on native host plants — the plants on which butterfly females lay eggs — as their sole source of food.
The good news? Their feeding typically doesn’t harm plants in the long run, though in large enough numbers they can cause severe defoliation. Skip ahead to control measures.
These crinkly critters are unable to travel long distances, so their moms take great care to lay eggs on just the right plants. In the case of monarch caterpillars, for example, they feed exclusively on milkweed plants. So if you want big, beautiful butterflies in your garden, you might want to think twice before shooing away their babies.
Learn more about these eccentric, ecologically valuable insects with Clyde Sorenson, entomology expert at NC State, in this edition of Homegrown In the Garden! Flutter on over to our Butterflies in Your Backyard guide for detailed steps to create a butterfly habitat at home.
North Carolina is home to a diverse variety of caterpillars. These crawling critters eventually transform into beautiful butterflies and moths, but first they must survive the larval stage. This article provides an in-depth look at the many species of caterpillars found across North Carolina.
Common Host Plants
Many caterpillars are specialists, feeding on only one or two types of host plants. Some of the most common host plants for North Carolina caterpillars include:
- Oak trees
- Cherry and apple trees
- Milkweed
- Vines like morning glory and pipevine
- Grasses
- Wildflowers like asters and violets
Caterpillars often do the most damage to their host plants at the end of summer when they are rapidly growing and preparing to pupate. Luckily, most of their preferred host plants are fast growing species that can quickly recover from defoliation.
Notable Species
With over 150 species documented, it’s impossible to cover all of the caterpillars in North Carolina. But some of the most common, unique, and recognizable species include
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Monarch caterpillars: These iconic black, yellow, and white striped caterpillars feed exclusively on milkweed.
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Eastern tent caterpillars They build large silk “tents” in trees where groups of caterpillars live together.
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Tobacco hornworms: These large green caterpillars have white diagonal lines and a curved horn on their rear. They can decimate tomato plants.
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Buck moth caterpillars: Covered in venomous spines, these black and yellow caterpillars can cause a painful sting.
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Woolly bear caterpillars: These fuzzy black and orange caterpillars prefer to feed on herbs and flowers.
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Saddleback caterpillars: With a brown “saddle” on their back full of stinging spines, these caterpillars should not be touched.
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Io moth caterpillars: Spiky and colorful, these caterpillars feed on a variety of deciduous trees.
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Puss caterpillars: Their cute furry appearance hides venomous spines beneath.
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Slug caterpillars: These green, plump, slug-shaped caterpillars are mostly harmless.
Caterpillar Habitats
Caterpillars in North Carolina can be found living in a diverse array of habitats, essentially anywhere that has an abundance of their preferred host plants. Some of the most common places to spot caterpillars include:
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Woodlands: Oak and hickory forests harbor many caterpillar species.
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Backyards: Milkweed, asters, and other common garden plants attract caterpillars.
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Agricultural areas: Caterpillars may thrive on crops like tobacco, corn, cabbage, and tomato. Some are considered agricultural pests.
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Wetlands: Milkweeds and grasses around wetlands provide food for many caterpillars.
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Roadsides: With an abundance of weedy flowers, roadsides are caterpillar hotspots.
Defense Mechanisms
Caterpillars have a variety of defense mechanisms to help them survive the dangers of the outside world. Some of the ways North Carolina caterpillars defend themselves include:
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Camouflage: Many caterpillars blend in with their surroundings, like those that mimic bird droppings.
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Chemical defenses: Caterpillars like monarchs store toxins from their host plants to deter predators.
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Stinging spines: The spines and hairs of some caterpillars can cause irritation, pain, and rashes.
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Cryptic silk nests: Tent caterpillars, fall webworms, and others build silk nests in trees for protection.
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Mimicry: Some caterpillars mimic the appearance of more dangerous insects.
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Quick escapes: Many drop to the ground or thrash wildly to escape predators.
When to See Them
The larval caterpillar stage is the longest phase of a butterfly or moth’s life cycle. In North Carolina, caterpillars are active from spring through fall, with peak activity in the summer months. The exact timing depends on the species and can vary based on environmental conditions.
Some species like tent caterpillars and monarchs have multiple generations per year, so their caterpillars may be spotted over a longer time frame. For most species, caterpillars are most abundant in late summer as they store up energy before transforming into butterflies or moths.
Managing Problem Species
While most species pose no threat, a small number of caterpillars become problematic agricultural pests that can damage crops. Common pest caterpillars include tobacco hornworms, cabbage loopers, corn earworms, fall armyworms, and yellow-striped armyworms.
For home gardeners, minor damage from less than 10 caterpillars per plant can often be tolerated. Handpicking pest caterpillars is an effective organic control method. Insecticides and organic Bacillus thuringiensis treatments can also be used sparingly for heavy infestations.
Though some may consider them pests, caterpillars are important consumers in their natural habitats. Their voracious feeding connects them to the surrounding ecosystem, and their metamorphosis into butterflies and moths helps pollinate plants and disperse seeds. With proper management, problematic species can be controlled while beneficial species are left to fulfill their ecological roles.
So next time you spot a caterpillar munching away on a leaf, take a closer look at these fascinating creatures before they transform and take flight as butterflies or moths. North Carolina’s diversity of species provides plenty of opportunities to find these crawling critters.
Living a Double Life
Caterpillars are found in almost every community across North Carolina. While they’re most prevalent — or visible at least — in spring and summer, different species of caterpillars are active during different times of the year.
Caterpillars, which are full of protein, fat and water, are key contributors to ecosystems as an essential food source for birds and other wildlife. They also help to regulate plant populations and play an important role in nutrient cycling (i.e., ecological recycling). Perhaps most importantly, adult caterpillars — moths and especially butterflies — are vital pollinators, meaning they help fertilize plants by spreading pollen so the plants can reproduce.
Stinging Caterpillars in North Carolina
FAQ
Are there any poisonous caterpillars in North Carolina?
Puss caterpillars, Megalopyge opercularis, are also called asp caterpillars because of their potent stings. They are called puss caterpillars because their thick, fluffy setae resemble the fur of a pussycat. Adults are called flannel moths because of their fluffy, wavy, flannel-like scales.
How do I find out what kind of caterpillar I have?
Look for distinct physical features if the caterpillar has any. Check to see if the caterpillar has a curled tail, head horns, knobs, lashes, spines, or a split tail. These can all be good indicators for certain caterpillar species and will help you narrow down your search rather quickly.
What are the black and brown caterpillars in NC?
The fuzzy brown and black creature commonly called the woolly worm or woolly bear is the larval form of the tiger moth (Isia isabella). Woolly worms appear in early fall, when they feast on common plants, and emerge in spring from the pupa stage as moths.
What caterpillars are invasive in NC?
Gypsy moth caterpillars, Lymantria dispar, are serious pests of forest and shade trees, as well as a nuisance to people. This hairy caterpillar has characteristic pairs of blue dots followed by pairs of red dots along its back. The male moth is a active flier and mates with winged but flightless females.