Butterfly Identification And Guide
Butterfly Identification -- What Kind of Butterfly Is This?
Identify the butterfly you saw in your garden with the help of this guide. This article will help you with butterfly identification, so you can identify the yellow and black butterflies flying around your buddleia bush, or the big black butterfly winging past you on a camping trip. Not every orange butterfly you see is a monarch! The butterflies of North America are many and varied, and to identify butterflies you will probably need some help. So here is a quick guide to butterfly identification for many of the common species in North America, complete with big pictures and a little bit about each species' immature forms and life histories.
The information in this article comes from my own 40-plus years of experience as an enthusiastic naturalist; all of the photos are public domain and credited accordingly. If you are a naturalist yourself and see anything I missed or got wrong, please leave me a comment!
How Do You Identify a Butterfly?
Simply put, a butterfly is a winged insect that undergoes complete metamorphosis (in other words, goes from egg to caterpillar to pupa to adult). Butterflies belong to a large group of insects called the Lepidoptera, which includes both butterflies and moths. It has three body segments, the head, the abdomen and the thorax. Butterflies are of course harmless, and connot bite or sting -- rarely some species can damage plants in your garden -- but they are a striking and valuable part of the life on our planet, so it's worth your time to be able to identify butterflies when you see them!
There are more than 700 different butterfly species in North America, and many live in specific ecosystems that the average person visits only rarely. The butterflies that have adapted to man-made environments like parks and gardens are the ones you will see the most. Many of these are quite beautiful, and to see them up close on a sunny day can be a real event. And if you can identify the butterfly you're looking at, the experience will be that much richer.
Monarch (Danaus plexippus)
This magnificent animal may be the most well-known, and most-loved, of all our insects. There is something truly regal about its size, bright colors, and powerful, soaring flight -- its kingly name supposedly comes from the spotted margins of its wings resembling the sable-edged robes worn by royalty at the time of its discovery. Nearly everyone has seen monarchs, and is familiar with their mind-boggling migrations and million-butterfly roosting in the mountain forests of Mexico. But there are more reasons to be fascinated with this species. For one thing, it is thought that the poisonous sap in the milkweed, the monarch's only food plant, makes it distasteful to predators like birds. This may be one reason why so many butterflies are orange -- they are all evolving to resemble the monarch, so birds will think twice before eating them, even if they are perfectly edible. This is the idea behind mimicry, and if it is accurate then the monarch is not only big and beautiful, but highly influential as well.
To see a striking example of mimicry in action, have a look at our next species, the Viceroy.
Viceroy (Basilarchia archippus)
It's hard to believe that this insect is completely unrelated to the monarch. The viceroy's relatives are nearly all black or dark blue. The viceroy gets its name from its resemblance to the popular monarch butterfly (they're both royalty -- get it?). They are so similar that this butterfly's identification relies largely on a quite minor difference in the hindwing markings.
The viceroy is one of the most well-known cases of "mimicry" among North American butterflies. The thinking among experts is that the monarch, which eats milkweed, is made poisonous by the caustic sap in the milkweed plant. This means that birds and other predators who have tried a nasty-tasting orange butterfly in the past will think twice when confronted with another one. Many butterflies in the monarch's range are orange like the monarch, possibly to gain protection from the resemblence, but the viceroy really takes it to an extreme.
Red-Spotted Purple (Basilarchia astyanax)
The red-spotted purple is closely related to -- get this -- the viceroy, the monarch-mimicking red-and-black butterfly pictured above. Even better, this pretty black and blue butterfly is believed to mimic the poisonous pipeline swallowtail (check this species out further down). That makes the Basilarchia genus a pretty amazing bunch of copy-cats, adapting over millions of years to resemble animals that are poisonous and protected from predators. The red-spotted purple is especially beautiful on the underside, so if you ever get to see one up close, you'll want to go get your camera.
Great Spangled Fritillary (Speyeria cybele)
This bright orange butterfly wings fast across fields and around forest edges in mid-to-late summer. Some researchers think its orange color is meant to mimic the poisonous monarch butterfly's colors -- if so, that makes it yet another in the orange-butterfly mimic category that may also include over a dozen unrelated species. The great-spangled has lovely silver spots on the underside, which gives the insect its common name. There are many similar, related species that occur across our area, many of which are quite rare and limited to specific areas in the mountainous western states.
Tiger Swallowtail (Papilio glaucus)
These big, beautiful butterflies can be identified by their bold yellow-and-black stripes -- hence the common name. Tigers have an unusual life history. The adults are on the wing in mid-summer, wheeling high among the branches of ash and cherry trees, where the big female lays her eggs. The caterpillar, which is green with little "false eye" spots near its head, feeds until it is about half grown, and then builds a little shelter by pulling together the edges of a leaf. It overwinters in this shelter, and in the spring emerges to continue feeding. It will pupate in early summer, and then the adults hatch to complete the process.
Another interesting fact about the tiger swallowtail is that some females, especially in the southern parts of its range, are almost all smokey dark brown in color. They hardly even look like tigers - panthers, maybe! Experts have suggested that the reason for this "dimorphic" phase is in order to mimiic the bad-tasting pipevine swallowtail, which is generally more common in the south than in the north.
Pipevine Swallowtail (Battus philenor)
This beautiful insect is the northern-most species of a large tropical genus (Battus) that includes some of the most striking swallowtail butterflies in the tropics -- which is saying something. The pipeline swallowtail is generally limited to the southern states, but it may be found nearly anywhere in our area, especially later in the summer as multiple broods spread north. This insect is believed to be the model for a number of other species that mimic the blue-on-black coloring. the larvae and the adult may be poisonous or distasteful to predators like birds and lizards, making it a good idea to look the same whether or not you yourself are poisonous.
Black Swallowtail (Papilio polyxenes)
This common butterfly occurs in one form or another over pretty much the entire North American continent. I chose to picture the male, which has more yellow on its hind wings; the female is larger and has much more blue on its hindwings, making it yet another North American butterfly that resembles the poisonous pipeline swallowtail. Black swallowtails have a very visible caterpillar, often called the "carrot-worm" because it eats, you guessed it, carrots. Here's a nice photo of the caterpillar -- maybe it looks familiar to you!
Cabbage White (Pieris rapae)
Not a true beauty, perhaps, but this plain white insect is by far the most successful butterfly in North America. It was introduced from Europe many years ago, and has found a home everywhere from your backyard garden to the wilds of western mountains. The very inconspicuous pale green caterpillar lives on the underside of many different leaves, especially cruciferous plants and other cultivars, and eats holes in the middle of the leaf, and the damage is very familiar to even the most casual gardener. You can see the damage, but good luck finding one of the larvae -- they are close to invisible. The butterfly is not protected by poisonous compounds, as far as is known for certain, and don't really resemble known mimicry models like the orange monarch or the black-and-blue pipeline swallowtail. But it has become the single most common butterfly in city and countryside.
Yellow Sulphur (Colias eurytheme)
These two species of bright yellow butterflies can be hard to tell apart, and often fly together, so I put them together here. They are among the first butterflies to appear each spring, and seem to have adapted very well to the disturbances humans cause in the landscape: look out over the close-cut monoculture of a golf course or city park grounds and you'll probably see a few of these very common butterflies dancing across the grass.
There are several other yellow species in the Coliadinae subfamily, and they all look much alike to the casual observer. For this guide, I am sticking to the most common. The next species is one worth singling out.
Clouded Sulphur (Colias philodice)
This species can be difficult to tell apart from the previous one.
Dogface Sulphur (Colias cesonia)
Usually only found in the South, this butterfly may be expected farther north as climate change alters the distribution of some species. This is a large, showy, and fast-flying butterfly that likes open fields and bright sunshine. They are legendarily difficult to catch. Note the "dog-face" profile in black on each upper wing that gives this insect its cool common name. I remember a field in Texas swarming with these butterflies; their speed and agility is impressive.
Pearly Eye (Enodia anthedon and associated species)
This subtly beautiful butterfly is best identified by the area in which it is found: the woods. It is relatively unusual to find large butterflies flying in woods or forests, and if the insect is pale brown, has round "eye-spots" bordering the wings, and tends to land vertically on tree trunks, then there is a good chance it is a pearly eye or one of its close relatives.
These pretty insects do have a somewhat unattractive habit - they like to feed on roadkill. I once found a big male happily feeding on a very dead possum on a lonely West Virginia forest road. Not the most appealing setting for such a pretty insect, but that's Nature for you.
Wood Nymph (Cercyonis pegala)
This is one of the most variable butterflies in our entire area. It occurs nearly everywhere in the US east of the Mississippi, but you could hold two specimens from different parts of its range in your hands and not think they were even related. Eastern populations tend to have bright yellow bands behind big round eye-spots on the upper wings, while western forms may have no yellow at all, very small eyespots, and be nearly twice as big. I chose an image of an individual that is more or less in the middle, but if you have a butterfly that looks a LITTLE like this, it may well be a form of C. pegala.
California Sister (Adelpha species)
A truly gorgeous butterfly, the California sister is big, fast, and hard to miss. It stops often to feed on roadkill or drink from puddles, and flashes those big beautiful markings when it does. This insect is one of the northern-most members of a huge group of tropical and sub-tropical butterflies, many of which show interesting variations on the markings of the California sister.
Milbert's Tortoiseshell (Aglais milberti)
I almost didn't include the species, because it's not terribly common and is hard to identify on the wing -- and with its constant patrolling behavior, it's almost always on the wing. But when a milbert's stops to drink from a puddle or a flower, it shows its wings, and for my money there's not a more beautiful butterfly in North America. It's related to several European species that are also striking, including the amazing peacock butterfly. Milbert's tortoiseshells are on the wing all summer, but some hibernate, and may come out on a warm spring day, sometimes when there's still snow on the ground.
Red Admiral (Vanessa atalanta)
The red admiral is yet another butterfly that some workers think is a mimic of the monarch -- though the monarch is bigger, brighter, and has different flight habits. Is it possible that we are witnessing a species in the process of changing to become a more accurate mimic? When you come down to it, there's no such thing as a species, in the sense of a fixed representative of an animal's permanent form -- everything is in flux, shifting towards more and more successful variations on their form. The red admiral, then, along with every other butterfly on this page, is simply the "current version." It would be so cool to hang around for another million years or so and see what these insects all look like then!
The Buckeye (Precis coenia)
Isn't this a gorgeous insect? It's a shame that it flies so fast, giving the average observer little chance to appreciate its beauty. The buckeye occurs throughout eastern North America, where its larvae feed on nettles. The butterfly likes to circle the same area and land in the same general spot, and you will most often see them on dusty gravel roads, where their brown ground color blends in surprisingly well. The big eyespots resemble a bird's or a lizard's, so when they snap their wings open the predator may be scared off.
Buckeyes also have a curious relationship with the large carolina grasshopper, which inhabits the same general space as the butterfly. When the grasshopper jumps, the buckeye will swoop down to "do battle" with the larger insect. Why they do this is not definitely known.
Question Mark (Polygonia interrogationis)
This is one of the angle-wing butterflies and is common in late summer.
Painted Lady (Vanessa cardui)
This insect is maybe the most "cosmopolitan" butterfly in North America, meaning it occurs pretty much everywhere in the world. The monarch is famous for its travels between the US and Mexico, but the painted lady can be found just about anywhere in the world. There is even a closely related species in the Hawaiian Islands. The painted lady is related to the buckeye and the red admiral, and like those species the caterpillar is spiny and will eat thistle and other common "weeds." I have found both the larva and the adult in deserts and mountain forests, and everywhere in between; sometimes their population "explodes," and a field will be nearly covered with thousands of these beautiful butterflies. This, by the way, is another butterfly that may mimic the monarch.
The Blues (Family Lycaenidae)
A very common group of butterflies is the blues, in the family Lycaenidae. These insects are small and quick-flying, and their delicate, pretty markings require an up-close look or a good photograph to appreciate. This family is especially abundant in the American west, and some mountain meadows have swirling clouds of blues of various species. The caterpillars are a little like fuzzy green slugs -- they creep slowly around the flower-tops of their food plants, where they are very nearly invisible, even to the trained eye.