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What is a spiky black caterpillar with red?

What is a spiky black caterpillar with red?

Spiky black caterpillars with red markings are a type of insect larvae that belong to the family of moths and butterflies known as Lepidoptera. Caterpillars are the immature form of butterflies and moths before they form their pupa and undergo metamorphosis into their adult winged form. There are many different species of black spiky caterpillars with red or orange markings, predominantly found in North America. Identifying the exact species can require close examination of distinctive features.

Distinctive Features of Spiky Black Caterpillars with Red

Spiky black caterpillars with red or orange markings have some key identifiable features:

– Long black bodies covered in branching spikes or prickly protrusions. This helps camouflage them against predators.

– Vivid red or orange markings along the sides or at the ends. These are warning colors to signal toxicity.

– Thick black spines or tufts of hair arising from protruberances on each segment. These contain venom for defense.

– Brightly colored feet or ‘prolegs’ on the underside. These help grip onto leaves and branches.

– A horn or tail-like protrusion on the rear. This is the osmeterium which releases a foul odor when threatened.

Common Species Identification

Some of the most common spiky black caterpillar species with red or orange markings in North America include:

Io Moth Caterpillar

  • Scientific name: Automeris io
  • Large size up to 2 inches long
  • Long branching black spines covering body
  • Red head with two distinct horns
  • Feeds on trees and shrubs like maple, oak, willow, ash, plum

Buck Moth Caterpillar

  • Scientific name: Hemileuca maia
  • Up to 2 inches long
  • Black spiky body with bright orange dots down sides
  • Red head with two short horns
  • Feeds on oak, birch, willow, cherry, blueberry

Hickory Tussock Moth Caterpillar

  • Scientific name: Lophocampa caryae
  • Up to 1.5 inches long
  • Long black tufts of hair on each segment
  • Red head and legs
  • Feeds on hickory, walnut, oak, ash, elm

Spiny Elm Caterpillar

  • Scientific name: Nymphalis antiopa
  • Up to 2.5 inches long
  • Branched black spines over yellow body
  • Red head with two black horns
  • Feeds on elm, willow, cherry, poplar, oak

Geographic Range and Habitats

Spiky black caterpillars with red markings are predominantly found throughout North America. Some exact species have more localized ranges:

– Io moth caterpillars range across southern Canada and the eastern and central United States.

– Buck moth caterpillars are found across southern Canada, the eastern U.S., and south to Florida and Arizona.

– Hickory tussock moth caterpillars inhabit eastern North America from southern Canada to Florida.

– Spiny elm caterpillars are found across southern Canada and throughout the continental United States except the Southwest.

These caterpillars inhabit a range of wooded habitats where their food plants grow, including:

– Deciduous forests with oak, maple, cherry, elm, birch, poplar, willow.

– Hickory-oak dominated woodlands.

– Mixed forests with shrubs and smaller trees.

Life Cycle and Metamorphosis

The spiky black caterpillars go through a complete metamorphosis with four life cycle stages:

Egg – Females lay eggs on the underside of leaves in clusters of 100-400 eggs. The eggs hatch within 1-2 weeks.

Larva – The larvae emerge and begin feeding on leaves. They molt 4-5 times over 2-6 weeks as spiky black caterpillars.

Pupa – The caterpillar forms a cocoon to pupate for 1-4 weeks before emerging.

Adult moth – The adult moth emerges with wings to reproduce and lay eggs for the next generation. Different species emerge in spring, summer or fall.

Feeding Habits and Diet

The spiky black caterpillars are voracious eaters feeding on the leaves of many trees and shrubs. Some details on their diets:

– Prefer the leaves of hardwood deciduous trees including oak, birch, maple, cherry, elm, willow, poplar, ash, plum.

– Hickory tussock caterpillars specialize in feeding on hickory and walnut leaves.

– Young emerging caterpillars may skeletonize and damage leaves.

– Older larva are wasteful feeders that eat holes in the center of leaves.

– Hickory tussock larvae tend to feed together and can defoliate branches.

– Buck moth caterpillars feed on both leaf upper and lower surfaces.

Defenses and Toxicity

The spiky black caterpillars have an array of physical and chemical defenses:

– Venomous spikes and hairs that cause irritation and rashes if handled.

– Bright warning colors to signal toxicity to predators.

– Foul-smelling osmeterium releases stench when threatened.

– Larvae regurgitate irritating fluids when attacked.

– Toxins make the caterpillars distasteful and potentially poisonous to eat.

While spiky and colorful, they are not dangerously venomous or fatal to humans. But sensitivities may cause more severe skin reactions in some. Best to admire without touching!

Threats and Predators

The spiky black caterpillars have some natural predators and threats in the wild:

– Birds like cuckoos and grackles may prey on them.

– Small mammals including shrews, mice, chipmunks may eat larvae.

– Insects like preying mantises, beetles and bugs may hunt young caterpillars.

– Parasitoid wasps and flies lay eggs on larvae as hosts. Their larvae then consume the caterpillars.

– Diseases caused by bacteria, viruses and fungi can infect populations.

– Harsh weather like late spring frosts can kill newly emerged larvae.

But birds and insects may learn to avoid their toxicity, reducing predation rates. Their spines, stench and toxins provide strong defenses against many predators.

Interactions with Humans

Spiky black caterpillars have some notable interactions with humans:

Positive Negative
valuCaterpillar hair Used by Native Americans for wampum beads and weaving Considered agricultural pests that can damage crops and ornamental plants.
Larval spikes Inspire innovations in self-cleaning surfaces, military camouflage, optical sensors. Venomous spines can cause mild skin irritation, rashes and allergic reactions in humans.
Adult moths Pollinate flowers and provide food for bats, mice, owls. Hickory tussock larvae can defoliate and weaken hickory trees used for timber.

Overall, while the caterpillars have some drawbacks, their positive ecological contributions and inspirational designs likely outweigh their pesky reputation.


In summary, the spiky black caterpillars with red markings comprise a variety of moth species in North America. They can be identified by their branched spines, warning colors, and feeding damage on deciduous trees. Their toxicity provides strong defenses, but they also face predators like birds and wasps. While considered garden pests, their ingenious designs and ecological roles demonstrate their importance in nature. So appreciate their uniqueness when spotting them, but save handling for the soft fuzzy caterpillars out there!