Saddleback Caterpillar

Acharia stimulea

Last updated: October 4, 2022
Verified by: AZ Animals Staff
© Liz Weber/Shutterstock.com

Saddleback caterpillars are solitary in nature, unlike many of their cousins that live in pairs or groups. They only intermingle when it's time to mate and lay eggs.

Saddleback Caterpillar Scientific Classification

Kingdom
Animalia
Phylum
Arthropoda
Class
Insecta
Order
Lepidoptera
Family
Limacodidae
Genus
Acharia
Scientific Name
Acharia stimulea

Read our Complete Guide to Classification of Animals.

Saddleback Caterpillar Conservation Status

Saddleback Caterpillar Locations

Saddleback Caterpillar Locations

Saddleback Caterpillar Facts

Name Of Young
Larvae
Group Behavior
  • Solitary
Fun Fact
Saddleback caterpillars are solitary in nature, unlike many of their cousins that live in pairs or groups. They only intermingle when it's time to mate and lay eggs.
Most Distinctive Feature
Sucker discs at the ends of their legs
Incubation Period
10 to 14 days
Average Spawn Size
30 to 50 eggs
Habitat
Ornamental shrubs and shade trees
Predators
Wasps and assassin bugs
Diet
Herbivore
Lifestyle
  • Solitary
Favorite Food
Cherries
Common Name
Saddleback caterpillar
Number Of Species
1799
Location
North America and Mexico

Saddleback Caterpillar Physical Characteristics

Color
  • Brown
  • White
  • Green
Skin Type
Exoskeleton
Lifespan
10 days after mating
Length
0.75 inches

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The saddleback caterpillar is a species native to North America and Mexico. They belong to Limacodidae, which also includes slugs and moths. They are green with brown heads and have a prominent brown dot surrounded by a white ring on the center of their bodies. This dot looks similar to a saddle, hence the name saddleback.

In addition, they are covered in spikey spines that sting if touched. These spines secrete venom that can cause pain and swelling in humans.

Saddleback Caterpillar Scientific Name

The saddleback caterpillars’ scientific name is Acharia stimulea, and they belong to the order Lepidoptera. This order contains over 180,000 species, and the name comes from the Greek words lepido (meaning scale) and pteron (meaning wing).

This order’s members have four wings covered in minuscule scales. In addition, they have exoskeletons, compounded eyes, two antennae, three body segments (head, thorax, and abdomen), and six jointed legs.

The saddleback caterpillar belongs to the family Limacodidae, which consists of approximately 1800 species.

Their preferred habitat is tropical regions for the humidity. Another name for this family is cup moths because their cocoons are shaped like cups after the adults emerge, and the lids are missing.

Because of the large number of species, they differ in size and structure. Some are round or square, and others are flat and appear slug-like.

Most family members are harmful because they have spikey hairs that inject their victims with poison, which can cause severe reactions in humans.

Their most distinguishing feature is their sucker discs at the ends of their legs that stick to smooth leaf surfaces.

Saddleback Caterpillar Appearance

These caterpillars are green with a distinctive brown dot surrounded by a white ring in the center of their bodies. This dot looks like a saddle, which is why they are named the saddleback caterpillar. In addition, they have protruding horns on both sides of their head.

Their body is also covered in spikey hairs that inject predators with venom if touched. Once they transform into moths, they are a dark brown color. However, the dot remains, but it is only visible when the moth opens its wings.

These caterpillars aren’t very big and only measure 0.75 inches in length. So compared to other species of caterpillars, they are tiny.

Saddleback Caterpillar Behavior

Saddleback caterpillars are solitary in nature, unlike many of their cousins that live in pairs or groups. They only intermingle when it’s time to mate and lay eggs.

These creatures communicate via body language. However, they can also feel vibrations. In addition, they make drumming or scraping noises with their mouthparts.

Saddleback Caterpillar Habitat

Saddleback caterpillars prefer habitats with ornamental shrubs and shade trees. However, they are found on various plant species, which they use as a food source and are essential for development.

Saddleback Caterpillar Diet

These caterpillars have a varied diet consisting of:

  • Pears
  • Cherries
  • Foliage
  • Roses
  • Various trees

Saddleback Caterpillar Predators and Threats

Although they have venomous spikey hairs covering their bodies, there are predators like the paper wasp and assassin bug that prey on these caterpillars.

Their biggest threat is the braconid wasp (Cotesia empretiae). These wasps lay eggs inside the saddleback, and when they hatch, the larvae start to eat the caterpillar from the inside.

Saddleback Caterpillar Reproduction, Babies, and Lifespan

Saddleback caterpillars lay between 30 to 50 eggs at once. The adult moths typically lay their eggs on the upper side of a leaf in clusters.

The eggs will start to hatch around 10 days later. Larvae exit the egg by chewing a hole in the membrane. They need to feed for approximately 4 to 5 months before forming pupating.

Lifespan

The average lifespan of an adult moth is only 10 days after mating.

Are Saddleback Caterpillars Harmful?

These caterpillars have harmful spines that sting because of the poison released upon touch. Symptoms can include:

  • Migraines
  • Anaphylactic shock
  • Gastronomical issues

That’s why if you ever encounter one of these beautiful specimens, you should never touch it; it will cause severe pain!

To treat a sting from a saddleback caterpillar, you need to wash the affected area with warm water and soap. After cleaning the area, apply an ice pack. Interestingly, using baking soda helps to reduce pain and swelling.

Luckily, these caterpillars’ poison is not fatal to humans, but they do come with numerous side effects. However, if the affected area is still painful after two days, you need to consult with your doctor.

How To Prevent Saddleback Caterpillars

To avoid coming into contact with the saddleback caterpillars, don’t plant the following trees:

  • Apple
  • Basswood
  • Cherry
  • Dogwood
  • Elm
  • Maple
  • Oak
  • Plum

In addition, you can spray Reclaim IT every three months to keep these caterpillars away.

Species Similar to the Saddleback Caterpillar

Several species are similar to the saddleback caterpillar; they include:

Spiny Oak-slug

Spiny oak slug moths are often in or near deciduous forests. The adults are nocturnal creatures, frequently found near light sources. They have brown bodies and minty green forewings with brown patches. In addition, they have brown hindwings. These moths are usually seen flying from late spring to autumn.

Hag Moth

Hag moths belong to the family Limacodidae, which includes many species of slug and caterpillars. Their larvae are very unusual because of their tentacle-like arms, which give the appearance of an octopus when they crawl. In addition, they are brown with short-haired coats.

Although their hairy coats are prickly, they do not sting like the saddleback caterpillar. Because of their strange appearance, the caterpillars attract more attention than adult moths.

Skiff Moths

Skiff moths larvae look more like a slug than a typical caterpillar. They are oval-shaped, green in color, and completely hairless. In addition, their backs are raised, forming a mound from head to rear. This raised mound can be green or brown in color.

To help them camouflage, their side ridges are raised close to the highest point, which makes them look like dead leaves to unsuspecting predators.

Their diet consists of:

  • Various trees
  • Blueberries
  • Bushes
  • Oak trees
  • Poplar trees
  • Willow Trees
  • Sweet gale

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About the Author

I am a 33-year-old creative and professional writer from South Africa. Wildlife is one of my greatest passions and led me to become the writer I am today. I was very blessed to work with an abundance of wildlife (mainly big cats) and captured my unique experiences in writing. But I wanted to take it further, and I ventured into the freelancing world. Now, I get to spend my days writing about animals; what could be better?

Saddleback Caterpillar FAQs (Frequently Asked Questions) 

Are Saddleback moths poisonous?

They are covered in spikey spines that sting if touched. These spines secrete venom that can cause pain and swelling in humans.

How do you treat Saddleback stings?

To treat a sting from a saddleback caterpillar, you need to wash the affected area with warm water and soap. After cleaning the area, apply an ice pack. Interestingly, using baking soda helps to reduce pain and swelling.

What is the deadliest caterpillar in the world?

The most dangerous caterpillar in the world is the Assassin or Lonomia obliqua.

Thank you for reading! Have some feedback for us? Contact the AZ Animals editorial team.

Sources
  1. Grow it Build it, Available here: https://growitbuildit.com/saddleback-caterpillar-acharia-stimulea/#lifecycle
  2. Wikipedia, Available here: https://en.wikipedia.org/wiki/Saddleback_caterpillar
  3. Kidadl, Available here: https://kidadl.com/facts/animals/saddleback-caterpillar-facts
  4. Butterflies and Moths, Available here: https://www.butterfliesandmoths.org/species/Acharia-stimulea
  5. Center for Urban Agriculture, Available here: https://ugaurbanag.com/saddleback-caterpillars/

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