Caterpillars - Baby Butterflies and Moths

EVERY CATERPILLAR IS UNIQUE

First you creep and then you fly:>)

Each kind of butterfly or moth is like no other, although they can be very close in appearance.  The caterpillars, likewise, may look similar but are not alike.  Most caterpillars (sometimes called "worms") are unknown to people, but certain ones, like the Monarch Butterfly caterpillar, tent caterpillars, and the always beloved Woolly Bears are familiar.

Some caterpillars are hairy, some spiny, some smooth.  There are a few in a group called "slug caterpillars" that can sting if you handle them and they have some ferocious spines.  Others, like the Wooly Bears, have folk lore surrounding them.  Some have projections on their backsides that look like tails. Certain caterpillars are crop pests.  All are interesting.

A butterfly or moth goes through four stages of development - first is the egg which is commonly laid on or close to a food plant.  This assures that when the egg hatches, the caterpillar (worm, larva) has food to eat and can grow.  Eggs are attached with a special glue and different types of butterflies or moths lay their eggs in different patterns, some singly and some in rows or other shapes.

As they grow, the skin they're in gets too tight and they must shed.  This is called an "instar".  The number of instars varies, but by the time a caterpillar reaches the final instar it often looks nothing like the very young version.  This picture shows at least three instars of the Milkweed Tussock Moth.

A caterpillar lives to eat, and it is excellent at that - Olympic quality performance:>)

When the last instar is reached and the caterpillar is ready to Pupate (make a cocoon or chrysalis that protects it while it morphs into the adult stage), it must build a shelter to sleep in.  Moths make cocoons and are often on or in the soil, while butterflies make a chrysalis (hard shell) and every species has a house of it's own design.  The period of sleep, or metamorphosis, varies and may be up to a year or only a few weeks.

When the transformation from caterpillar to adult is complete, the adult breaks a hole in the chrysalis or cocoon and pushes it's way out.  Then it must find a twig or something like that to hang from, and it begins to move it's wings.  This is how they pump the wings into their full size since they are born with their wings in a wrinkled wad all crumpled up.  The pumping movement makes their blood flow into the wings.  The wings gradually harden and the adult is ready to fly, sip nectar, mate, lay eggs - voila!  Circle of life is complete:>)

I have a couple field guides to recommend to you if you decide to pursue the somewhat daunting task of identifying the caterpillars you find.  For years there were no good guides around, then a few appeared and they are very good.

The smallest and simplest to use is the Peterson First Guides, Caterpillars, by Amy Bartlett Wright, published by Houghton Mifflin Company, 1993.  It is arranged by how they look (smooth, hairy, smooth with spines, etc.) and is illustrated with excellent drawings in color.  The guide also tells you where to find them, how to raise them, what to feed them.  Great for a project with children!

My favorite and by far the most inclusive is Caterpillars of Eastern North America by David L. Wagner.  It is published Princeton University Press and is a Princeton Field Guide.  This book is nicely laid out with photographs of both the caterpillars and the adult moths or butterflies.  It gives a wonderful natural history, tips on identifying them, the range, the food plants, and some ancillary notes.  If you don't have a working knowledge of these creatures, you'll end up looking through the whole book to find your prize and identify it.  The pictures are so lovely, you won't mind:>)  As you use the guide you'll become familiar with where certain caterpillars fall in regard to their appearance and the looking will get easier.

I've made it a goal to find more and different caterpillars this year.  Meantime, here are a few from our local area.

Bagworm on Multiflora Rose

Bagworms are often found on evergreen trees but you amy find them anywhere.  I found this one on a branch of a Multiflora Rose.  Inside this silken sack decorated with bits and pieces of plant materials is either a female or larva (caterpillar).  The little ones hatch from their eggs inside the bag then leave Mom's house to build their own bag-house.  When mature, the males leave the bag and fly around looking for love.  Females are wingless and legless and stay in their bag even when adult.  Bags can be up to two inches in length.  The bagworm increases the size of it's home as it grows.

Saddleback Caterpillar

Although these are not uncommon, I haven't seen one in years - until last fall, that is, when I got stung! This guy was on a small cherry tree that I decided to use as a grasping post as I leaned out over a stream bank to take a picture.  He looks none the worse for wear, so I imagine I only brushed the spines.  that's enough to give you a hand full of hurt, however.  I was on foot and about a half hour's walk from home, so I hoped the sting wouldn't cause more trouble than the immediate pain.  It didn't, but without knowing what time would bring, I cut my picture-taking short and walked home.  A paste of baking soda and water helped, and in a day it was all gone:>)  This is the caterpillar's was of protecting itself and it does work.  the caterpillars grow to about one inch long and like to eat cherry, oak, apple, roses, corn, and blueberries.  As an adult the moth it is a two-shaded brown critter  - pretty but  not fancy.

Appalachian Blue or Silvery Blue caterpillar attended by it's ant keepers.   See the white arrow on the right
under the Black Cohosh stem.

These are tiny caterpillars, smooth and hairless, that eat the Black Cohosh buds.  They are tended by ants who care for them like we would care for herds of cattle or sheep.  They move the caterpillar around to prime feeding grounds and protect them from predators like the flies and wasps that paralyze them and use them for baby fly or wasp food.  In return the caterpillar feeds them a sweet excretion from the 7th abdominal segment. This is like maple syrup to us - a much desired, sweet ant food that they earn for all their hard work as caterpillar shepherds.

There are butterflies commonly called Blues, Hairstreaks, Metalmarks, and Coppers that belong to one huge family.  Over half of these cooperate with ants - an amazing number of species that have complicated interactions with their keepers.  In some species the ants actually take the caterpillars inside for the night and return them to their food source in the mornings.  All the caterpillar types tended by ants have a specialized means of creating vibrations in their bodies that run through the food plant to call their ants for help when they need it.  A few of these caterpillars live in ant nests and eat the larvae of the ants.  Some types of ant/caterpillar relationships are fine unless the ants are hungry, then they'll eat the caterpillar.  I believe most have just settled into a mutually beneficial, non-lethal relationship:>)

Eastern Tent Caterpillars on Pear Tree

These caterpillars are very common, considered pests of fruit trees, and lovely.  They build a silken web in the crotch of a tree (never on the terminal ends of branches) and the web is expanded as the caterpillars grow in size.  They leave the nest during the day to feed on leaves then return to the safety of the web at night.  These are seen in Spring and are not Fall Web Worms which behave similarly.  These are fuzzy caterpillars with pretty blue dots along each side; there's a pale streak down their back.  The moth is a soft brown with two parallel stripes on the front wings.

I don't have a picture of a Gypsy Moth larva, but they are very like these guys except they have five dots of red behind their head and the rest of the body segments have blue dots.  The Woods Tent Caterpillars are a gorgeous light shade of blue.

Bird Poop Caterpillar (My term)

I call them the Bird Poop caterpillars because, if you don't look closely, they look like bird poop!  I guess it's a great camouflage trick.  This may be any of a number of field-type butterflies like skippers or even a moth.  It was resting under a leaf in the hot part of the day.

Yellow-striped Armyworm

Isn't this a beautiful caterpillar!  You could design a room around these colors.  It becomes a small, pale gray or brown moth.

Common Pug Moth Caterpillar

The Common Pug Caterpillar is very common, extremely variable in color, but it usually has this herringbone pattern.  they eat everything and have many generations each year.  I easily find them among the Black-eyed Susans or on our mint.  They over-winter as pupae.  they seem able to camouflage themselves by adjusting their color somewhat, but that is merely anecdotal and I find no studies on this possibility.  The adult moth is kind of a "Plain Jane" brown with darker markings.

I believe this is a Fall Webworm caterpillar and it was eating my ornamental Sweet Potato Vine!  Kind of cute, don't you think:>)

Fall Webworms can have anywhere from one to four or five broods a year - less in the cold north, more in the hot south.  Their web nests are seen on the terminal ends of branches (not in the crotches of tree branches) and they can be efficient defoliators of whole trees.  they are colonial (living in communities of many individuals) and may host many parasitoids of their species - parasitoids are the insects that use the caterpillars as food.  They hatch into a bland, white moth.

Ruby Quaker Moth

Ruby Quaker Moth on Apple Tree

These are common and quite variable in color/pattern which makes them tough to ID.  The become  dark brown moth, patterned like tree bark.  They eat almost anything they find:>)  The moth is dark brown and nondescript.

This could also be a Ruby Quaker Moth

Very young Tobacco Hornwork.  His "tail" will turn red as he matures.

Tobacco Hornworm

Typical pose - Tobacco Hornworm

Although most people call these caterpillars Tomato Worms, they are not.  The red "tail" gives them away and we can ID them as Tobacco Hornworms that feed on tomatoes, tobacco, potato, and other members of that plant family.  A black tail when they are large means they are the Tomato Hornworms.

Both these wonderful caterpillars can grow up to six inches long when lucky enough to reach their last instar (shedding of the skin).  That is just before they pupate (make a case and go to sleep while they turn into an adult moth).  Their moth form is a sphinx moth, or hawk moth - large and beautifully patterned on the tops of their wings with many shades of brown.  These are sometimes called hummingbird moths because of their wide wings and stout bodies, and there are many kinds, not just the Tobacco and Tomato kinds:>)

They are often prey for parasitic wasps and most of the ones we see on our tomato plants have eggs on them that will hatch and the baby wasps will consume the caterpillars.

Woolly Bear Caterpillar

Woolly Bear Caterpillar

Woolly Bear Caterpillar

Woolly Bear Caterpillar

Who doesn't know the Woolly Bear Caterpillar?  What child hasn't sought them out to play with them and watch them roll into a protective ball?  These cuties eat dandelions, plantains, grasses and other low weeds.  They weave a cocoon from their own bristles. Almost fully grown caterpillars over-winter in a secure spot (under a log for instance) and make their cocoon in the spring.

The moth is called the Isabella Tiger Moth, and it can have a wingspan of up to two inches.  They are a yellow-brown color with a yellow abdomen that has black spots in three lines running down the length of it.

There is an Old Wives' Tale that says the width of the bands can predict the severity of the upcoming winter - not so, say I (and many other people, too).  These bands vary in width as they grow with brown becoming more and more prominent as each instar is reached, and it has no predictive value.  Still, it's fun and does no harm:>)

This looks like a Fritillary Butterfly caterpillar to me.  We commonly have the Great Spangled Fritillaries around for  most of the summer, so I'm guessing this is a baby:>)

Great Spangled Fritillaries are handsome, orange brown butterflies with silver spots on the underwings.  They aren't as large as a swallowtail, but they are medium sized.  They love the butterfly bushes and milkweed.

Great Leopard Moth Caterpillar

I just put a large one of these outside today.  I found it on the floor - another mystery that will never be solved!  They are large and bristled - black with red bands that really stand out when they roll into a ball for protection.  When running, they move like lightening:>)  They eat an eclectic mix of plants that include cherry trees, violets, sunflowers, plantains, willow, and dandelion - YAY, MOTH!  The adults are gorgeous white moths covered with black rings.

Snowberry Clearwing Hawk Moth Caterpillar on a Honeysuckle Bush

Snowberry Clearwing Hawk Moth Caterpillar on a Honeysuckle Bush

This caterpillar is dark brown, a coloration less often seen than the yellow-green of most of them.  It becomes a day-flying hummingbird moth, and  I think they look like little flying crayfish because of the colors.  They fly and hover like hummingbirds, and they like to rest one front foot on the flower they're taking a sip from.  As caterpillars they like to eat Viburnum and Honeysuckle as well as some other things, and we have plenty of those two favored foods.  As adults they drink nectar.  The name "Clearwing" comes from the transparent places on the forewings - the scales wear off and you can literally see through the wings.

American Dagger Moth

These become pretty whitish-yellow moths with a distinctive zigzag dagger shape on the forewings.  Caterpillars make a cocoon of their hair and leaves of a food plant then sleep through the winter.  They eat willow, maple, oak, and some other trees.

Banded Tussock Moth

There are a number of different kinds of Tussock moths.  The color is somewhat variable but they have these wonderful tufts of hairs, called "pencils" and a dark line down their backs.  They eat elm, ash, cherry, apple, and box-elder - trees quite common in our area.  It becomes a pretty, pale-colored moth and this gives it a common name of Pale Tussock Moth.

Hickory Tussock Moth

Hickory Tussock Moth

This is a white, fuzzy caterpillar with black tufts and spots.  They love to eat hickory, but almost any tree will do like pecan, walnut, oak, willow, and ash.  The eggs are laid in large numbers so when the caterpillars are quite young you may find many in a small space keeping company.  The moth has dark brown forewings with white spots and pale underwings.

Milkweed Tussock Moth - This one literally ate everything around him!

Milkweed Tussock Moth - Note the numbers states of development, called instars.

These caterpillars are found on milkweed and seem to like being in the company of many others. Nature seems to decree that any caterpillar, as it grows and needs more food, will eventually separate itself from it's relatives and go off on it's own.   I love how these guys are the perfect Halloween colors:>)  The moth is plain, kind of tannish, with a bright yellow abdomen that has a line black spots.

Monarch Caterpillar on Milkweed

Monarch Caterpillar on Milkweed

Monarch Caterpillar on Milkweed - can you tell front from back?  The larger, black protuberances are the front.

Monarch Caterpillar on Milkweed

Monarch Caterpillar on Milkweed

Monarch Caterpillar on Milkweed

Since we are on milkweed as a food source, how about the large and very handsome Monarch Caterpillar!  I see most of these caterpillars fall prey to the parasitic wasps - bad news since Monarchs are in trouble everywhere.  Their final destination for their migration is a forest in Mexico which is being cut down at a scary rate.  All along the Monarch's migration fly route, houses and other development are taking away habitat.  Add the parasitic wasps as yet another stressor and trouble is inevitable.  Monarch numbers are rapidly diminishing.

Some folks are taking to raising them and releasing them in an effort to boost numbers.

These are so pretty with their black, yellow and white colors, and the fleshy protuberances both front and back confuse predators.  Because they eat milkweed, Monarch caterpillars and butterflies build up a toxin that has a horrible taste.  One try at eating one of these fellows generally teaches a bird or whatever to leave them well enough alone.

We all can probably identify a Monarch Butterfly:>)  Did you know scientists actually capture them, band them, and release them in an effort to learn more about their travels and troubles?

Yellow Bear Caterpillar - Virginian Tiger Moth

Yellow Bear Caterpillar - Virginian Tiger Moth

Yellow Bear Caterpillar - Virginian Tiger Moth

Yellow Bear Caterpillar - Virginian Tiger Moth

Yellow Bear Caterpillar - Virginian Tiger Moth

 Perhaps the most common caterpillar in yards is the Yellow Bear.  They eat just about anything (one of the above pictures shows a Yellow Bear on and Oregano leaf from our garden) and usually have at least two generations in one year.  These caterpillars begin as a light beige, almost white, color and grow darker as they shed.  Each new instar is a little darker, and they end up a very dark brown or reddish-brown.  The adult moth is a fuzzy, chunky, white moth that I think is beautiful.

I want to make a note here about the fuzzy, bristled caterpillars.  They are harmless, but some people are sensitive to the hairs and can have an allergic reaction that makes them itchy.  If you begin to feel itchy when holding them, be sure not to get your hands near your face and go wash your hands well.  This is not common, in my experience, and I'm only mentioning it because it can happen.

As always, thank you for making time to come by and visit!  Have a wonderful weekend:>)