What kinds of caterpillars can you find in South Dakota?
Caterpillars are some of the MOST fascinating insects in the world! It always amazes me that caterpillars eventually turn into butterflies or moths.
There are hundreds of different caterpillar species found in South Dakota!
Since it would be impossible to list them all in one article, I chose the 19 most interesting and common ones to share with you. 🙂
#1. Monarch Caterpillar
- Danaus plexippus
- This famous caterpillar is plump with black, white, and yellow bands.
- Its legs and pro-legs are pronounced, and each end of its body has spindly black tentacles.
- The Monarch’s preferred host plant is milkweed.
Like the adult butterfly, the Monarch is one of the most well-recognized caterpillars in South Dakota!
Their distinctive stripes and tentacles make them look cartoonish. But this highly visible coloring sends a message to predators: Back Off!
Monarch Caterpillars are toxic to most animals, and at the very least, taste bad! This poison comes from their diet, which is almost entirely made up of milkweed. Toxins from the milkweed plant stay in the caterpillar, producing a bitter taste and poisonous effects.
If you have milkweed in your yard or nearby, your chance of finding Monarch Caterpillars is excellent! Honestly, there is nothing more fun than finding these colorful insects on our milkweed plants and getting to watch them transform into adults!
- Coloring is light green with small yellow dots along the sides.
- This species is small and relatively thin and appears velvety.
- Cabbageworms’ host plants are Brassicas, including cabbage, kale, broccoli, and chard.
In South Dakota, this species is often called the Imported Cabbageworm because it isn’t native to North America. It was introduced in shipments of cabbage and other brassica plants and soon became an invasive species.
Cabbageworms are considered agricultural pests and can do severe damage to crops to their host plants. Cabbage, brussels sprouts, broccoli, and cauliflower are all susceptible to damage. For a home gardener, the best way to deal with Cabbageworms is to prevent a large infestation. Plant covers, regular weeding, and varied plantings can all help with preventing this hungry invader!
One reason Cabbageworms are so damaging is that they are voracious eaters! They can easily skeletonize entire plants, eating everything but the toughest stems and midveins. Boring through heads of cabbage and making huge dents in broccoli are no problem for this Very Hungry Caterpillar!
Cabbageworms grow into Cabbage White Butterflies, which are one of the most abundant butterflies in South Dakota! If you see a white butterfly in the spring, chances are it’s a Cabbage White!
#3. Viceroy Caterpillar
- Limenitis archippus
- The coloring is mottled brown or green and white to resemble bird droppings.
- Two dark-colored horns on the head and small spines on the body.
- The chrysalis also resembles bird droppings hanging from a tree branch.
- The preferred host plants of Viceroy Caterpillars are willow, poplar, and cottonwood trees.
Viceroy Caterpillars are one of the ugliest caterpillars in South Dakota!
This is by design; their lumpy, mottled appearance makes them look like bird droppings, warding off predators!
Interestingly, this isn’t the Viceroy’s only protection against predators. Viceroy Caterpillars eat plants that are rich in salicylic acid, which they store in their bodies. When predators try to eat them, they are rewarded with a strong, bitter flavor and an upset stomach. One taste and they learn to stay away!
Viceroy Caterpillars primarily live in open forests or fields, and they’re found across many different climates. Look for them during spring and summer, which is when the adults typically mate.
Interestingly, Viceroy and Monarch Caterpillars look almost identical.
#4. Large Maple Spanworm
- Prochoerodes lineola
- Gray-brown coloring with small black spots scattered on the body. Often this species has a bark-like pattern.
- Thin and stick-like with a knob on each end.
- Large Maple Spanworms use a huge variety of plants and trees as hosts: birch, maple, cherry, apple, oak, poplar, walnut, and willow trees; geranium, soybean, blueberry, and currant plants; and grass.
This species has one of the best camouflages of any caterpillar in South Dakota!
Large Maple Spanworms look exactly like a bit of twig on a tree, even from up close! So, it’s hard to imagine any predator observant enough to try and eat one, which is precisely its goal.
Their camouflage is the only defense Maple Spanworms have because they aren’t poisonous. They’re a favorite snack for determined birds!
When they’re not imitating sticks, Large Maple Spanworms have an interesting way of getting around! They plant their front legs, arch their back in the air, and bring their back legs forward to meet their front. Then, they throw their front forward and repeat the whole process. They’re one of many caterpillars that move like this, earning them nicknames like inchworm, looper, or spanworm.
Large Maple Spanworm Moths are just as adept at camouflage as their larva – they look exactly like dead leaves clinging to a branch!
#5. Variegated Fritillary Caterpillar
- Euptoieta claudia
- Stripes of black, red, and white run the length of the body.
- Black branched spines stick out from each body segment in even rows.
- Variegated Fritillaries will use any plant in the violet or alder family as a host plant. These include common blue violets, yellow alder, and pansies.
Variegated Fritillary Caterpillars share the same name as their adult-form butterflies. They eat ornamental plants like violets, pansies, and passionflower.
Look for these caterpillars in South Dakota in meadows, open lots, and fields.
The Variegated Fritillary’s chrysalis is the most beautiful of all the caterpillars in South Dakota. This protective shell is where the caterpillar transforms into the adult butterfly. Its pearly white color and shiny gold spikes make it look like an expensive jeweled pendant!
#6. Curve-Lined Owlet Moth Caterpillar
- Phyprosopus callitrichoides
- The coloring is shades of brown and cream, occasionally near black.
- The distinctive body shape is spiky, contorted, and asymmetrical, like a dry leaf.
- Greenbriers are the host plant of choice for this species.
There’s a good chance you’ve seen a Curve-Lined Owlet Caterpillar in South Dakota!
However, you may not have even realized it because this species is an expert at camouflage. Its body is meant to look like a dry, curled leaf clinging to a branch. I think it succeeded!
Interestingly, it isn’t only the larva of this species that hide in plain sight. Curve-Lined Owlet Moths also have coloring and texture that resembles a dry leaf. So, it seems like even though the insect goes through a complete metamorphosis, it keeps some of the survival traits into adulthood!
The host plant of the Curve-Lined Owlet Caterpillar is greenbrier, a vine plant common in many habitats. This species prefers woodland and nearby clearings, but it’s sometimes spotted in more developed areas like office parks or lush backyard gardens.
#7. Parsley Caterpillar (Black Swallowtail)
- Papilio polyxenes
- The coloring is bright green, with rings of black and yellow dots down the length of the body.
- The head and thorax are slightly larger than the back, and the legs and pro-legs are pronounced and visible even from a distance.
- Parsley plants are the preferred host of this species.
Parsley Caterpillars, sometimes called parsley worms, are the larva of the Black Swallowtail butterfly. They get their name from their preferred host and favorite snack, the parsley plant.
At first glance, it’s easy to mistake a Parsley Caterpillar for a Monarch. But, the coloring is slightly different, and the stripes on the Monarch Caterpillar are a bit thinner. It would also be unusual for a Monarch Caterpillar to eat parsley or other garden herbs since they eat milkweed almost exclusively!
If you’re a gardener, you might consider Parsley Caterpillars a bit of a nuisance since they can decimate a parsley plant quickly. But, if you plant some extra, you’ll be rewarded with sightings of the beautiful Black Swallowtail butterfly in a few weeks!
#8. Eastern Tiger Swallowtail Caterpillar
- The coloring is bright green with two large eyespots in white, black, and blue.
- The thorax is much larger than the middle and tail, giving the caterpillar the look of an enlarged head.
- The favorite host plants of this species are the tulip tree and wild black cherry.
This species is one of the strangest-looking caterpillars in South Dakota!
The appearance of Eastern Tiger Swallowtail Caterpillars is so unique they inspired a Pokemon! Caterpie (the Pokemon) has the same features, including its horn-like Osmeterium, bulbous thorax, and large round eyespots. I consider this to be quite an honor! 🙂
This caterpillar’s primary defense is mimicry, using its unique shape and coloring to imitate a snake’s head. Additionally, as a young caterpillar, its color is brown and white to mimic bird droppings!
Interestingly, the adult Eastern Tiger Swallowtail Butterfly stands out in a crowd with its unique coloring and pattern.
Another defense of the Eastern Tiger Swallowtail is its Osmeterium, a horn-like organ that can be projected from the caterpillar’s head. Its dual functions are to mimic a snake’s forked tongue and to smell horrible to predators! Interestingly, to humans, the odor is strong but pleasant, like grass and pineapple!
#9. Cecropia Moth Caterpillar
- The coloring of this species changes with each instar growth. Most commonly seen in late instar; green with yellow, blue, and red bumps topped with black spikes.
- It has a large, fleshy body and very obvious leg appendages.
- Cecropia Caterpillars prefer birch, cherry, and maple trees for host plants.
Cecropia Caterpillars look more like aliens than anything!
Their bulbous bodies and multicolored, spiked nodules truly look like something from a sci-fi movie.
Look for Cecropia Caterpillars on maple, birch, and apple trees during late spring. They remain in their caterpillar stage for about two weeks before encasing themselves in their chrysalis for winter.
This species is one of many caterpillars in South Dakota called a “silkworm”. The name refers to the silk cocoon they spin around their chrysalis in preparation to become a moth. The cocoons are brown and cling to the side of host plants, and look like dead leaves.
As strange as Cecropia Caterpillars look, it’s nothing compared to the adult Cecropia Moth. Not only is the pattern and coloring beautiful, but this moth is also ENORMOUS! In fact, it’s the largest moth in North America!
#10. Io Caterpillar
- Automeris io
- The coloring is green with two stripes along each side, one red and one white.
- Tufts of short green spines cover the body, with patches of light green showing through.
- Io Caterpillars use hackberry and willow trees as host plants.
Io Caterpillars are highly venomous, and their sting is excruciating!
Fortunately, the sting is rarely severe enough to seek medical attention. Instead, most experts recommend removing the spines with scotch tape, then applying ice to the sting. Over-the-counter antihistamines and pain relievers can also help.
Of course, the best way to stay safe is to avoid touching Io Caterpillars. Since they’re so recognizable, this should be pretty easy!
Their tufts of green spines are distinctive and hard to miss against darker green leaves or brown bark. The red and white stripes on the sides are also helpful – they clearly say, “Stay back, I’m dangerous!”
If you know you’re going to be gardening or doing yard work in an area with Io Moths or their caterpillars, it’s a good idea to wear a hat and gloves. That way, if you happen to brush against one, you won’t have to worry about exposed skin!
Adult Io Moths are just as distinctive as their larva – if not more so! They have a beautiful pattern with large, prominent eyespots. There are two color morphs:
#11. Painted Lady
- Vanessa cardui
- The caterpillars’ coloring is variable, ranging from greenish-yellow to charcoal. Most have light-colored spots.
Look for Painted Lady caterpillars in South Dakota in open areas that are quiet and undisturbed, like roadsides, pastures, and gardens.
The population of Painted Lady’s can drastically differ from year to year. It’s common for them not to be seen for years in some places, then suddenly show up in significant numbers.
The Painted Lady is the only butterfly that mates year-round! Because of its constant migration pattern, it spends its entire life in suitable areas for its eggs to hatch.
#12. Red Admiral
- Vanessa atalanta
- The caterpillars are pinkish-gray to charcoal with white spots. They have spines along the back that resemble hairs.
Look for this caterpillar in South Dakota near the edge of forests in moist habitats.
Red Admiral Butterflies have a unique favorite food – they love fermented fruit! If you’d like to attract them, try placing overripe cut fruit in a sunny spot in your yard.
Red Admirals are migratory butterflies. They fly south toward warmer climates in winter and then move north again in late spring when food is more plentiful.
If you’re looking for a butterfly that’s easy to observe, you’re in luck! Red Admirals are very calm and easy to approach and frequently land on humans!
- RELATED: How to Attract Butterflies: 17 Tips!
#13. Pearl Crescent
- Phyciodes tharos
- Caterpillars are dark brown with cream stripes and spines all over their bodies.
The Pearl Crescent caterpillar’s preferred host plant is the Aster. Any flowering plants in your yard will attract this beautiful butterfly, but for best results, try to find one native to your area.
Look for Pearl Crescent butterflies in South Dakota near moist ground.
They prefer open, sunny habitats, but many locations suit their needs, including forest edges, fields, meadows, and gardens.
When the caterpillars grow into butterflies, they will feed on the nectar of the Asters as well!
#14. Mourning Cloak
- Nymphalis Antiopa
- Caterpillars are black with white specks and a row of red spots on the back.
Mourning Cloak caterpillars are most often found near deciduous forests. However, their habitat includes many developed areas like suburban yards, parks, and golf courses.
You might have a hard time finding this caterpillar in South Dakota.
Even though it’s fairly widespread, its preference for cold weather and solitary habits make it hard to spot, even for avid butterfly enthusiasts!
Mourning Cloaks are often the first butterflies to become active in the spring! In fact, some adults are even active through winter on warm days when snow is still on the ground.
They’re also one of the longest-lived butterflies, with some individuals living up to ten months!
#15. Forest Tent Caterpillar Moth
- Malacosoma disstria
Forest Tent Caterpillar Moth populations fluctuate in cycles, so you may go years without seeing any and then see lots of them in one season. Their populations reach outbreak proportions every 6-16 years.
Adult Forest Tent Caterpillar Moths are active in July, don’t feed, and live for ten days. Especially in outbreak years, you might spot large groups clustered around outdoor lights.
Unlike other tent caterpillars, Forest Tent Caterpillars don’t spin true tents. Instead, they spin silk mats on the tree’s trunk or branches where they rest when they’re not feeding.
#16. Western Tent Caterpillar Moth
- Malacosoma californica
In the fall, Western Tent Caterpillar Moths lay about 150 to 250 eggs in oval-shaped masses. They cover the eggs with a gluey cement substance called spumaline, which helps hold in heat and absorbs rainwater to prevent the eggs from drying out. It also protects the eggs from parasitoid wasps.
Even though it only takes three to four weeks for the caterpillars to mature, they must overwinter in this stage before pupating into moths. Their name comes from the silken tent they create to protect themselves from extreme cold during this time.
These caterpillars have a voracious appetite and can quickly defoliate trees in South Dakota during a population outbreak. While it may be unsightly, the trees usually recover just fine. Interestingly, these caterpillars have regional tastes, and the specific trees they prefer are highly dependent on their location.
#17. Checkered White
- Pontia Protodice
Checkered White caterpillars are common in South Dakota.
One of the most fascinating characteristics of this butterfly is its ability to use UV signals to communicate. These amazing insects can tell the difference between males and females of their species based on the UV radiation they give off! If a female notices that there are a lot of other females, she will migrate to a less dense population in hopes of attracting a mate.
Checkered White Range Map
Checkered White females lay their eggs on the host plants’ fruits and sometimes the stems. The larvae prefer to eat the flower or fruit of the host plant instead of the leaves.
This butterfly prefers open and sunny areas like deserts and plains, and it’s often found in vacant lots, airports, railroads, and dry grassland.
#18. White-lined Sphinx
- Hyles lineata
In the spring, the adult females lay hundreds of eggs on host plants. Occasionally, explosive outbreaks of this species occur, and during these times, you might see large groups of caterpillars moving together. They have even been reported to cover entire sections of roadways!
The caterpillars pupate in burrows underground. Pupation takes about two to three weeks, and when they’re close to finished, they wiggle up closer to the surface of the soil before emerging as adult moths.
White-lined Sphinx Moths are sometimes mistaken for hummingbirds. They can rapidly beat their wings to hover at flowers and reach in to sip nectar with their long proboscis. Their favorite flowers include Cardinal Vine, Jimsonweed, Petunia, Phlox, Lilac, Hostas, Honeysuckles, Evening Primroses, and Penstemon.
#19. Two-Tailed Swallowtail
- Papilio Multicaudata
Two-Tailed Swallowtail caterpillars are found in South Dakota in areas with open space and plenty of sunlight. Look for them in foothills, canyons, valleys, woodlands, roadsides, parks, cities, and suburb gardens.
Males of this species spend their entire lives finding a female to mate with due to their short lifespan. If it takes a long time to find a mate, males search for nutrients in rotten material, dirt, and sometimes feces, an odd behavior called mud puddling.
Although it’s one of the most recognizable features, the Two-tailed Swallowtail doesn’t need its tails to fly. Instead, they’re often used to escape predators. When a predator attacks the Swallowtail and grabs onto its tail, it breaks off, allowing the butterfly to escape.
Do you need more help identifying caterpillars in South Dakota?
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Which of these caterpillars have you seen in South Dakota?
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