A Caterpillar-Raising Extravaganza!

Cecropia Moth caterpillar in its last stage of development. July 2017. © Barb Elliot. Click to enlarge.

By Barb Elliot, Ph.D.

In July 2017, I came home from Mothapalooza, a conference for moth enthusiasts, with a Cecropia moth (Hyalophora cecropia) caterpillar.  I was excited.  The beautiful adult Cecropia (Hyalophora cecropia) is the largest moth in North America with a wingspan from 5″ – 7″. The showy caterpillars are chunky and grow to 4”- 4.5”. Although I had raised butterfly and moth caterpillars previously to increase their chances of survival, I now had the opportunity to observe the life cycle of this iconic silk moth and learn about its role in our ecosystem.

My caterpillar was almost full grown, but still had a voracious appetite. I kept it in a butterfly cage, provided a constant supply of fresh River Birch leaves, and removed the caterpillar waste (frass) each day.  Cecropia caterpillars can eat other native tree and shrub leaves including elm, oak, maple, apple, cherry, ash, sassafras and willow, but prefer to stick to one kind once they begin eating. A Cecropia caterpillar gains more

Cecropia caterpillar making its silk cocoon enclosure. © Barb Elliot. Click to enlarge.

than a thousand times its weight between hatching from its egg to being fully grown and ready to pupate and spin its cocoon.

In late summer, my caterpillar clung to a twig in the cage and spun a cocoon around itself.  Inside the protective silk, it changed from a caterpillar to a dark brown pupa, the third stage in its development.

A completed Cecropia cocoon. © Barb Elliot. Click to enlarge.

Many months later, on June 21, 2018, with metamorphosis complete, a spectacular female Cecropia moth emerged (eclosed) from the cocoon. With only a week to live and with no mouth parts to eat and drink, this adult female’s sole job was to mate and lay eggs.

Cecropia moth female newly eclosed from her cocoon. June 21, 2018 © Barb Elliot. Click to enlarge.

I decided to keep the moth outside overnight to see if she could attract a mate.  At dusk, I put her in a wire cage with holes sufficiently large for mating to occur.  A male, with its large, feathery antennae, can detect the pheromones a female emits and hone in from over a mile away.

I got up at 5 AM the next morning to check on her.  A male was clinging to the cage and mating with her!  The two mated all day and de-coupled just before dark.  Right away she began laying eggs.  I released the male so he could mate with other females.

Mating Cecropia moths. Note the male’s (on right) larger, more feathery antennae. © Barb Elliot. Click to enlarge.

During the overnight hours, she laid about 130 eggs.  After she rested, I released her so she could lay more eggs and live in the wild for the rest of her short life.

Cecropia eggs – two days old. June 27, 2018.

I kept five eggs and donated the rest to several environmental organizations and a few caterpillar-savvy friends. Three of my eggs hatched on July 4th, ten days after being laid.

My Cecropia eggs after three hatched.  Note the two with exit holes chewed by the tiny caterpillars. July 4, 2018.  © Barb Elliot. Click to enlarge.

Each ¼” black, spiny caterpillar chewed a hole in its leathery brown egg and almost immediately began eating the River Birch leaves I provided.  Within two or three days, the caterpillars outgrew the skin of their initial first stage (instar) and molted into a second instar.  Each time a caterpillar molted, the new skin was “loose” so it could continue its rapid growth. All three ate, grew, and reached the fifth instar, their final caterpillar stage.

Newly hatched Cecropia moth caterpillar – first instar. . July 4, 2018. © Barb Elliot. Click to enlarge.

First & second instar Cecropias.  9 days old. July 13, 2018. © Barb Elliot. Click to enlarge.

Two Cecropia cats molting from 2nd to 3rd instar; one still in 2nd instar. 11 days old. July 15, 2018. © Barb Elliot. Click to enlarge.

More mature 3rd instar Cecropia. 22 days old. July 21, 2018. © Barb Elliot. Click to enlarge.

Two fifth instar Cecropias and one 4th instar. 31 days old. Aug 3 2018. © Barb Elliot. Click to enlarge.

While my Cecropias were growing, I got an opportunity to raise another large silk moth.  On July 13, a friend noticed a large moth at the foot of a light pole – a Royal Walnut Moth or Regal Moth (Citheronia regalis).   Unfortunately, the moth was dead but had laid eggs before succumbing.  This hapless moth, like countless others, was drawn to nighttime outdoor lights, but was unable to escape the lights and died.

Dead Royal Walnut Moth by light pole with eggs. July 13, 2018. © Barb Elliot. Click to enlarge.

Of about 25 eggs I kept five and donated the rest to the Academy of Natural Sciences.  Just one of mine hatched and I began feeding Black Walnut leaves, one of its host plants, to the tiny fierce-looking caterpillar.  This caterpillar, known as the Hickory Horned Devil (HHD), is the largest caterpillar species in North America.  This species also goes through five instars before pupating. Although harmless, each stage looks scary and unpalatable, intended to make a bird or other hungry predator steer clear of such a high-protein meal.

Newly hatched Hickory Horned Devil caterpillar. July 24, 2018. © Barb Elliot. Click to enlarge.

Second instar of the Hickory Horned Devil. Aug 1, 2018. Day 9. © Barb Elliot. Click to enlarge.

Third instar of the Hickory Horned Devil. Aug 6, 2018. Day 14. © Barb Elliot. Click to enlarge.

Fourth instar of the Hickory Horned Devil. Day 20. © Barb Elliot. Click to enlarge.

Early 5th instar of the Hickory Horned Devil. Aug 16, 2018. Day 24. © Barb Elliot. Click to enlarge.


Hickory Horned Devil 5th instar, now greener with some blue near the head. Aug 19, 2018. Day 26. © Barb Elliot. Click to enlarge.

Fifth instar, Hickory Horned Devil. Some blue starting in a few spots on top of body. Aug 22, 2018. Day 30.


Hickory Horned Devil in final 5th instar colors – ready to pupate. Wikipedia image by Chris Hibbard.

Hickory Horned Devil Pupa. Winter 2018-2019. © Barb Elliot. Click to enlarge.

To my astonishment, I was raising the moth species with the largest caterpillar along with three caterpillars of the largest moth species.  By the end of August, all three Cecropia caterpillars made their cocoons. My almost hotdog-sized HHD caterpillar turned into a dark brown pupa during the first week of September. This species doesn’t spin a cocoon like its Cecropia relative, but digs down into the soil to pupate and spend the winter.  To simulate an underground environment. I provided an enclosure filled with crumpled paper towels, and the caterpillar pupated there successfully.  When temperatures turned frigid, I moved the HHD pupa into my refrigerator for safe-keeping over the winter.  As I had with their mother, I kept the Cecropia cocoons outside and waited for spring.

All three Cecropia moths eclosed – a male on May 22nd, and females on June 22nd and 25th – and I released them after dark on those nights.

The second of my 3 Cecropias to eclose from its cocoon – a female on June 22, 2019. © Barb Elliot. Click to enlarge.

Unfortunately, the HHD pupa died, so that huge, spectacular caterpillar didn’t become a beautiful Royal Walnut Moth as I had hoped.  In nature, less than 5% of caterpillars survive to become butterflies or moths.

A live Royal Walnut Moth. (Citheronia regalis). © Paul Scharf via dpr.ncparks.gov

Because they are active only at night, it’s rare for us to see Cecropia, Royal Walnut, or other large moths.  However, they and their caterpillars are key food sources for birds and other animals and thus are important members of our local food webs.  You can help keep them flying by providing native trees and shrubs that caterpillars need for food.  If you have outdoor lights, use timers or motion detectors so they are not on from dusk to dawn.  Of course, don’t use pesticides, which kill not just moths and caterpillars, but other beneficial insects, many of which are in steep decline.  If you’d like to see these and other interesting moth species, attend a local moth night event, perhaps  during National Moth Week in July, or have a moth night of your own.  I wish for you a Cecropia Moth, Royal Walnut Moth, and other magnificent nighttime moth wonders!

National Moth Week: Why? What Good are Moths?

By Barb Elliot

Moths, really? Yes, we’ll celebrate moths this coming week, July 19 – 27. During National Moth Week public and private moth-watching events will occur. Mothing, the practice of attracting, viewing, and photographing moths is growing immensely in popularity. But some are puzzled and ask, “What good are moths?” Butterflies are great, but moths are nasty.  After all, moth caterpillars eat tomato plants, make holes in wool clothes, eat flour and cereal in our kitchens, and can be agricultural pests. This is all true, but harmful moths are but a small fraction of moth species. Most are actually very important and beneficial to the environment.

The Cecropia Moth has a 6 inch wingspan.  Creative Commons photo. Click to enlarge.

The Cecropia Moth.  Creative Commons photo. Click to enlarge.

In fact, moths are closely related to our much-loved butterflies. Both are in the scientific order Lepidoptera, meaning “scaly wings”. All butterflies and moths have four wings covered with colored scales. Both groups go through four life stages: egg, larva (caterpillar), pupa (chrysalis/cocoon), and adult (butterfly/moth). Adult butterflies and moths also have a proboscis – a thin, straw-like tube for sipping nectar. However, all butterflies fly during the day, but most moths fly at night.  The tips of butterfly antennae are club-like, while moth antennae are

Butterflies antennae tips are club-like.  Photo from National Moth Week presentation.

Butterflies antennae tips are club-like. Photo from National Moth Week. Click to enlarge.

Moth antennae come in three forms.  Photo from National Moth Week.

Moth antennae come in three forms. Photo from National Moth Week. Click to enlarge.

more varied in structure. . Some moths have hairy-looking elongated scales on their bodies. These may provide greater protection from the environment and help them maintain their temperature – useful on cool nights.

But what good are moths?  Widespread and numerous (nearly 13,000 species in the U.S. vs. just 1,000 butterfly species) they play key roles in ecosystems. As pollinators of night-blooming plants, they are very important.  Unlike bees, moths do not eat or gather pollen.  However, their hairy bodies collect and spread pollen as they move from plant to plant.

Dark-banded Owlet moth sipping nectar from Common Milkweed in Barb's yard.  Photo © Barb Elliot.  Click to enlarge.

Dark-banded Owlet moth sipping nectar from Common Milkweed in Barb’s yard. Photo © Barb Elliot. Click to enlarge.

Many plants depend on this nocturnal pollination to maximize seed production.  A few cannot reproduce at all without moth pollination.  The proboscis of some moths can be many inches long, enabling the moth to reach nectar at the end of elongated flower tubes that are too long for bees.

Moths, both adults and caterpillars, are key food sources for many animals. Other insects, spiders, birds, bats, frogs, toads, lizards, rodents, foxes, and even bears consume moths. As indicators of biodiversity and the health of our environment, they function as “canaries in the coalmine.” Almost all moth caterpillars require specific plants as food.  Less diversity in native plants means less food for moth caterpillars and therefore, fewer species and numbers of moths. The result — less food to power the web of life.

Luna Moth.  © Edie Parnum. Click to enlarge.

Luna Moth. © Edie Parnum. Click to enlarge.

Many moths are beautiful, like the lovely Luna Moth.  Less impressive moths are often  masters of mimicry or camouflage.  Some mimic scary-looking animals such as snakes. Others, such as the Io Moth, have huge “eyes” to startle predators.  Some look like bark, dead leaves, lichens, or even bird droppings– making it almost impossible to spot them.

IO Moth revealing its"eyes" for startling predators.  © Barb Elliot.  Click to enlarge.

IO Moth revealing its”eyes” for startling predators. © Barb Elliot. Click to enlarge.


Copper Underwing Moth camouflaged on tree bark.  © Barb Elliot.  Click to enlarge.

Copper Underwing Moth camouflaged on tree bark. © Barb Elliot. Click to enlarge.








I find moths to be downright interesting creatures.  For instance, the beautiful and large adults of the Giant Silk Moth family have captivating life histories. These moths, such as the Luna, Tulip-tree, Cecropia, or Polyphemus, live for only a week or two — just long enough to attract or search out mates and for females to lay eggs.  With reduced mouthparts, these moths are unable to eat.  Females emit chemical scents called pheromones to attract males.  Males in this family have large, feathery antennae to detect pheromones from as far as seven miles away. They want to make a beeline to the female!

Moths come in a variety of shapes and sizes.  Some are as tiny as the tip of a pencil.  The Cecropia Moth (shown above), our largest moth, has a 6” wingspan.  Some rest with their wings flat. Many hold them vertically like some butterflies. Others fold them like tents over their bodies.

Yellow-collared Slug Moth with its abdomen curled up.   © Edie Parnum.  Click to enlarge.

Yellow-collared Slug Moth with its abdomen curled up. © Edie Parnum. Click to enlarge.

A few curl their abdomens up above their wings, an odd posture that is likely part of their mimicry or camouflage.  Sphinx or Hawk moths display outstanding flight dynamics. They can fly very quickly, hover, and move rapidly from side-to-side.  In fact, the flight aerodynamics of some Micro-aerial Vehicles’ (MAVs) are being designed by the military to emulate Sphinx moth flight.

Both Edie, my Backyards for Nature colleague, and I now consider ourselves to be “moth-ers”.  We frequently have “moth nights” in our yards. We attract the moths by shining special lights onto a white sheet, a place where they can land. By painting fermented bait onto tree trunk, we can attract moths that don’t come to lights. We follow Moths of the Eastern United States on Facebook and note what moths are being seen by other enthusiasts.  In June, Edie and I attended Mothapalooza, a weekend moth conference in Ohio.  With 150 participants, it sold out within two weeks of being announced – a testament to the burgeoning popularity of mothing. We visited five mothing stations that hosted thousands of moths.  We were up until the wee hours, but had great fun.

Try mothing yourself.  At first keep it simple. Leave your porch light on for the evening. Go out periodically to see what moths have flown in.  With a flashlight, look for moths nectaring on your flowers.  Fragrant, white, and pink flowers are particularly alluring.  Look closely,

Ultronia Underwing sipping juices from rotting fruit. © Barb Elliot.  Click to enlarge.

Ultronia Underwing sipping juices from rotting fruit. © Barb Elliot. Click to enlarge.

and you’ll see each moth using its proboscis to suck up nectar.  Or, put out a plate of rotting fruit and check for moths that stop by for a sugary drink.

Invite family and friends for a moth night in your yard.  See Edie’s Moth Night  blog post from last year for moth night ideas, a bait recipe, and host plants for moth caterpillars.  Check the National Moth Week website for public events in your area and tips on finding moths.  All across the United States and in many countries of the world, moth-ers will be celebrating moths.

Moths are good!  They play key roles in the web of life.  Plus, they are fascinating creatures.  These gems are outside your door at night.  Try mothing, but I warn you that it can become addictive.  Like a treasure hunt, you never know what may fly in.  Become a moth-er and … welcome to the dark side!


Beadle, David & Leckie, Seabrooke.  Peterson Field Guide to Moths of Northeastern North America.  Houghton Mifflin Harcourt, 2012.

Himmelman, John.  Discovering Moths:  Nighttime Jewels in Your Own Backyard.  Down East Books, 2002.