Insects & spiders
Is that a butterfly or a moth, and which one?
The butterfly-or-moth question has one reliable answer and it is not "moths fly at night". Look at the antennae. A butterfly's end in a distinct club or knob; a moth's are feathery, or thread-like and tapering, and never clubbed. Everything else — colour, flight time, wing posture — has too many exceptions to trust.
Narrow it down
Showing all 28 species
-
Monarch
Danaus plexippus
Deep orange with heavy black veins and a black border spotted white. Males have a small black scent patch on a hindwing vein. Glides on flat wings between wingbeats.
In the record 799,895 georeferenced records · half of them Jul–Sep · most distinctive in January · mostly from the United States check on GBIF
-
Viceroy
Limenitis archippus
A monarch at three-quarters size with one extra black line curving across the hindwing veins. Flies with quicker, flatter, more erratic wingbeats.
In the record 54,362 georeferenced records · half of them Jul–Aug · most distinctive in September · mostly from the United States check on GBIF
-
Painted lady
Vanessa cardui
Salmon-orange marbled with black and white, with four small eyespots along the underside of the hindwing. Migrates in enormous irruptions in some years.
In the record 1,577,323 georeferenced records · half of them May–Jul · most distinctive in June · mostly from the United Kingdom check on GBIF
-
Red admiral
Vanessa atalanta
Velvet black with a bold scarlet band across each forewing and along the hindwing edge, and white spots at the wingtip. Territorial and will approach a person standing in its patch.
In the record 3,185,303 georeferenced records · half of them Jun–Aug · most distinctive in October · mostly from the United Kingdom check on GBIF
-
Mourning cloak
Nymphalis antiopa
Deep maroon-brown with a ragged cream border and a row of blue spots inside it. Overwinters as an adult, so it is often the first butterfly seen in late winter on a warm day.
In the record 247,233 georeferenced records · half of them Apr–Jun · most distinctive in April · mostly from Finland check on GBIF
-
Eastern tiger swallowtail
Papilio glaucus
Large, yellow, with four black tiger stripes on each forewing and a tail on each hindwing. Some females are entirely black, mimicking the poisonous pipevine swallowtail.
In the record 127,549 georeferenced records · half of them Jul–Aug · most distinctive in March · mostly from the United States check on GBIF
-
Black swallowtail
Papilio polyxenes
Black with two rows of yellow spots, a band of blue on the hindwing and an orange eyespot with a black pupil near the tail. Caterpillars feed on parsley and dill.
In the record 118,300 georeferenced records · half of them Jun–Aug · most distinctive in March · mostly from the United States check on GBIF
-
Cabbage white
Pieris rapae
Plain white with black wingtips and one black spot on the male forewing, two on the female. The commonest butterfly in most gardens and the parent of the cabbage caterpillar.
In the record 3,687,718 georeferenced records · half of them Jul–Aug · most distinctive in April · mostly from the United Kingdom check on GBIF
-
Clouded sulphur
Colias philodice
Lemon-yellow with a narrow dark border, and a small silver spot ringed pink on the underside of the hindwing. Always settles with the wings closed, so the upper side is rarely seen.
In the record 60,685 georeferenced records · half of them Jun–Aug · most distinctive in October · mostly from Canada check on GBIF
-
Eastern tailed-blue and spring azure
Cupido comyntas, Celastrina ladon
Tiny, powder blue above and pale grey speckled below, often gathering in numbers at damp mud. The tailed-blue has a minute hair-like tail and two orange spots at the hindwing edge.
In the record 15,109 georeferenced records · half of them Jul–Aug · most distinctive in January · mostly from the United States check on GBIF
-
Great spangled fritillary
Speyeria cybele
Bright orange above with dark chevrons; the underside of the hindwing carries big silver spots on a rich brown ground, which is the diagnostic feature.
In the record 62,911 georeferenced records · half of them Jun–Jul · most distinctive in June · mostly from the United States check on GBIF
-
Common buckeye
Junonia coenia
Brown with six large multi-coloured eyespots — two on each forewing, two on each hindwing — and two orange bars near the leading edge. Basks on bare ground with wings flat.
In the record 95,263 georeferenced records · half of them Jun–Sep · most distinctive in November · mostly from the United States check on GBIF
-
Silver-spotted skipper
Epargyreus clarus
Stout, hairy and fast, with a bright silver-white patch on the underside of the hindwing. Skippers sit with the forewings raised and the hindwings flat, a posture nothing else uses.
In the record 95,171 georeferenced records · half of them Jun–Jul · most distinctive in June · mostly from the United States check on GBIF
-
Luna moth
Actias luna
Pale sea-green with a purple leading edge, a translucent eyespot on each wing and long sweeping tails on the hindwings. The adult has no mouth and lives about a week.
In the record 47,535 georeferenced records · half of them May–Jul · most distinctive in March · mostly from the United States check on GBIF
-
Cecropia moth
Hyalophora cecropia
The largest moth in North America: red-brown with white crescent moons on every wing, a red and white band and a furry red body. Males find females by pheromone from several kilometres.
In the record 13,844 georeferenced records · half of them Apr–Jun · most distinctive in January · mostly from the United States check on GBIF
-
Polyphemus moth
Antheraea polyphemus
Tan to reddish-brown with a large transparent-centred eyespot on each hindwing, ringed yellow, blue and black. The eyespots are flashed to startle a predator.
In the record 53,407 georeferenced records · half of them May–Jul · most distinctive in February · mostly from the United States check on GBIF
-
Io moth
Automeris io
Males are plain yellow, females purple-brown, and both flash a huge black-and-blue eyespot on the hindwing when disturbed. The caterpillar stings.
In the record 24,812 georeferenced records · half of them May–Jul · most distinctive in December · mostly from the United States check on GBIF
-
Hummingbird clearwing
Hemaris thysbe
A day-flying moth that hovers at flowers with a loud hum and a whirring blur of wings, with large clear panels in the wings and an olive and burgundy body. Constantly reported as a baby hummingbird.
In the record 21,951 georeferenced records · half of them Jun–Jul · most distinctive in July · mostly from the United States check on GBIF
-
White-lined sphinx
Hyles lineata
A fast, heavy, streamlined moth with a white stripe down each forewing and a broad pink band across the hindwing, hovering at flowers at dusk. Often mistaken for a hummingbird.
In the record 56,270 georeferenced records · half of them Mar–Jun · most distinctive in March · mostly from the United States check on GBIF
-
Tomato and tobacco hornworm moth
Manduca species
A large grey-brown sphinx moth with a row of orange-yellow spots along each side of the abdomen. The adult of the green hornworm caterpillar found on tomatoes.
In the record 49,129 georeferenced records · half of them Jun–Aug · most distinctive in January · mostly from the United States check on GBIF
-
Isabella tiger moth
Pyrrharctia isabella
A modest yellow-orange moth with faint dark spots — famous entirely for its caterpillar, the black-and-rust woolly bear crossing roads in autumn.
In the record 73,490 georeferenced records · half of them Aug–Oct · most distinctive in October · mostly from the United States check on GBIF
-
Rosy maple moth
Dryocampa rubicunda
Bright candy pink and lemon yellow with a woolly body — an implausible-looking moth that turns up on porch screens in early summer and is often assumed to be a toy.
In the record 26,552 georeferenced records · half of them May–Jun · most distinctive in June · mostly from the United States check on GBIF
-
Underwing moth
Catocala species
Forewings mottled grey and brown for perfect bark camouflage, hiding hindwings banded in vivid orange, red, pink or white that flash when it takes off.
In the record 364,916 georeferenced records · half of them Jul–Aug · most distinctive in September · mostly from the United States check on GBIF
-
Spongy moth
Handle with careLymantria dispar
Males are brown with feathery antennae and fly by day in a fast zigzag; females are heavy, near-white with dark chevrons, and barely fly at all. A major forest defoliator.
In the record 146,176 georeferenced records · half of them Jun–Jul · most distinctive in June · mostly from the Netherlands check on GBIF
-
Clothes moth
Tineola bisselliella
A tiny plain golden-buff moth that runs and scuttles rather than flying to a light. The damage is done by the larvae in wool, silk and feathers, not by the adult, which does not feed.
In the record 2,907 georeferenced records · half of them Mar–Jun · most distinctive in January · mostly from Germany check on GBIF
-
Indian meal moth
Plodia interpunctella
A small moth whose forewing is pale at the base and coppery-brown beyond a sharp dividing line. Larvae leave silk webbing through flour, cereal, nuts and dried fruit.
In the record 30,882 georeferenced records · half of them May–Aug · most distinctive in January · mostly from Germany check on GBIF
-
Peppered moth
Biston betularia
White finely speckled with black, resting flat against a lichen-covered trunk. The dark melanic form that spread during industrial pollution and receded afterwards is the textbook case of natural selection observed in the wild.
In the record 299,596 georeferenced records · half of them Jun–Jul · most distinctive in June · mostly from the United Kingdom check on GBIF
-
Hummingbird hawk-moth
Macroglossum stellatarum
Hovers at flowers by day with an audible hum and orange hindwings, uncoiling a very long proboscis. The commonest "I saw a hummingbird in England" report.
In the record 371,576 georeferenced records · half of them Jun–Aug · most distinctive in March · mostly from France check on GBIF
Nothing in this key matches every filter at once. That usually means one observation is off — a colour read in shade, or a size guessed rather than measured. Clear the filter you are least sure about and look again.
The only reliable butterfly-or-moth test
Almost every rule people are taught about this has exceptions large enough to sink it. The antennae do not.
- Antennae — this is the test. Butterflies have a thin shaft ending in a distinct club or knob. Moths have feathery, comb-like or thread-like antennae that taper to a point. No North American butterfly has feathery antennae, and no moth has a true club.
- Time of day — unreliable. Hundreds of moth species fly by day, including the hummingbird clearwing, the spongy moth male and every burnet and clearwing.
- Wing posture — mostly true, easily broken. Butterflies typically rest with wings closed above the back and moths flat or tented, but skippers hold forewings up and hindwings flat, and several butterflies bask with wings open.
- Colour — useless. The luna, rosy maple, io and underwing moths are more spectacular than most butterflies, and the commonest garden butterfly is plain white.
- Body build — a decent supporting clue. Moths tend to be stouter and furrier, butterflies slimmer and smoother, which reflects the thermoregulation needs of flying at night.
Worth knowing for context: butterflies are a small group inside the moths, not a separate one. There are roughly 750 butterfly species in North America and around 11,000 moths, so a random Lepidopteran on a porch light is overwhelmingly likely to be a moth.
The mimicry pairs, and why they exist
Several of the confusions in this key are not accidents of appearance — they are the point of the appearance.
Monarch and viceroy. The classic textbook example, and the textbook explanation was wrong. It was long taught as Batesian mimicry, a palatable viceroy copying a toxic monarch. Feeding experiments in the 1990s showed the viceroy is itself unpalatable, making it Müllerian mimicry: two genuinely defended species converging on one warning pattern, so predators only have to learn it once. Separating them takes one look at the hindwing, where the viceroy has an extra black line crossing the veins.
Black swallowtail females and the pipevine swallowtail. Female eastern tiger swallowtails come in a dark form, and both they and the spicebush swallowtail converge on the appearance of the pipevine swallowtail, which is genuinely toxic from the aristolochic acid in its host plant.
Clearwing moths and bees. Several moths have transparent wing panels and banded abdomens, and hover at flowers in daylight looking convincingly like bumblebees or hornets. Predators leave them alone.
Eyespots. The large false eyes on a polyphemus or io moth are not mimicry of a specific animal so much as a startle display: flashed suddenly they give a bird a fraction of a second's hesitation, which is enough. Small marginal eyespots on butterflies do something different, deflecting a strike away from the body to a disposable wing edge.
Why moths come to lights, and what to do about it
The best-supported explanation is not attraction in the ordinary sense. High-speed videography published in 2024 showed that moths near an artificial light do not steer towards it — they turn their backs to it. Flying animals use the bright sky above and the dark ground below to keep their dorsal side up, and a point source of light on the ground breaks that reference, sending the animal into an endless banking turn around the lamp.
The consequence is that light pollution is a genuine conservation issue rather than a nuisance. Moths trapped circling a lamp all night do not feed, do not mate and do not pollinate, and moths are major nocturnal pollinators. Insect biomass declines recorded across Europe and North America correlate with artificial light at night among other drivers.
Practical mitigation, in descending order of effect: turn outdoor lights off when nobody needs them; use motion sensors; use warm-coloured bulbs at 2700 K or below, since blue-rich white light is disproportionately disruptive; shield fixtures so light goes down rather than sideways and up; and lower the brightness. All of these are also better for the people using the space.
If you want to see moths deliberately, the same physics works for you. A white sheet with a light behind it on a warm, still, humid, moonless night will bring in dozens of species, and it is the standard method for moth surveys everywhere.
Gardening for butterflies and moths
Adults need nectar and caterpillars need specific host plants, and almost every "butterfly garden" gets only the first half right. Nectar draws adults passing through; host plants make a garden a place they breed.
| Plant | Supports |
|---|---|
| Milkweed (Asclepias) | Monarch — and nothing else will do |
| Parsley, dill, fennel, carrot | Black swallowtail |
| Oak | Several hundred moth species; the single most productive tree for Lepidoptera in North America |
| Willow, cherry, birch, poplar | Viceroy, mourning cloak, luna, cecropia, polyphemus |
| Violets | Fritillaries, which feed only at night |
| Nettles | Red admiral, painted lady, several tortoiseshells |
| Spicebush and sassafras | Spicebush swallowtail, promethea moth |
Three other things matter more than plant choice. Do not use broad-spectrum insecticides, including systemic neonicotinoids, which persist in nectar and pollen. Leave leaf litter and standing stems over winter, because a large proportion of moths overwinter as pupae in litter or as eggs on stems, and an autumn tidy-up removes next year's population. And accept chewed leaves: a garden with no caterpillar damage is a garden with no butterflies.
Recording what you see
Lepidoptera are among the best-recorded insect groups, and amateur records do real scientific work. Monarch population monitoring, the UK Big Butterfly Count and the National Moth Recording Scheme all run largely on public submissions, and long-run amateur datasets are what made the peppered moth story and the current insect decline measurable in the first place.
To photograph one usefully: get the upper side and the underside if you can, because many species are identified from the underside pattern rather than the top. Include something for scale, and note the date and the location. For moths at a light, photograph them at rest on the sheet rather than trying to hold them; wing scales rub off on fingers and a rubbed moth is harder to identify and less likely to survive.
28 entries here cover the species most often photographed in North American gardens and porches, plus the common European crossovers. With around 11,000 moth species in North America, a great many small brown moths are not identifiable from a photograph by anyone, and specialists say so plainly. BugGuide, iNaturalist and regional moth groups all identify submissions free.
What the observation record shows
Every entry in this key that carries a scientific name is matched against GBIF, the international register of biodiversity records, and against iNaturalist. That puts a hard number behind 28 of the 28species here: 11,295,820 georeferenced records across the 26 entries that resolve to a single species, spanning 11 families, the oldest of them collected in 1996. The snapshot was taken on 2026-09-04.
That evidence is not spread evenly, and it is worth knowing before you trust a narrow result. The five best-recorded species in this key hold 85% of all the records between them: Cabbage white alone accounts for 3,687,718, while Clothes moth has 2,907. A common thing is common in the data too, so when a filter narrows to one frequent entry and one rare one, the frequent one is usually the answer — and the record count is the quickest way to see which is which. The same skew applies geographically: 38% of these records come from the United Kingdom, so the key describes what is reported there far better than it describes anywhere else.
When these are actually reported
Half of every record for this group falls in July–August. A raw month count measures two things at once — when the organism is about, and when people are outdoors with a camera — and the second effect is large enough to give almost anything a summer peak. The line on the figure divides each month by the baseline for every species in every Orvik key, which answers a different question: relative to when people record anything at all, when are these species recorded? Values above 1.0 are the months that belong to this group rather than to the season. On that measure 16 of the 26species here peak outside the warm half of the year — Red admiral, Monarch, Hummingbird hawk-moth among them. Those are the ones a seasonal rule of thumb gets wrong.
Records behind each entry
Sorted by how much evidence exists, not by how likely you are to meet one. The peak month is the effort-adjusted figure, and it is left blank wherever the sample is too thin for the month-to-month wobble to mean anything.
| Entry | Accepted name | Rank | GBIF records | Research-grade | Half fall in | Peak, adjusted | Most reported from |
|---|---|---|---|---|---|---|---|
| Cabbage white | Pieris rapae | species | 3,687,718 | 262,993 | Jul–Aug | April | the United Kingdom |
| Red admiral | Vanessa atalanta | species | 3,185,303 | 290,895 | Jun–Aug | October | the United Kingdom |
| Painted lady | Vanessa cardui | species | 1,577,323 | 204,548 | May–Jul | June | the United Kingdom |
| Monarch | Danaus plexippus | species | 799,895 | 532,510 | Jul–Sep | January | the United States |
| Hummingbird hawk-moth | Macroglossum stellatarum Linnaeus, 1758 | species | 371,576 | 51,075 | Jun–Aug | March | France |
| Peppered moth | Biston betularia | species | 299,596 | 19,804 | Jun–Jul | June | the United Kingdom |
| Mourning cloak | Nymphalis antiopa | species | 247,233 | 96,125 | Apr–Jun | April | Finland |
| Spongy moth | Lymantria dispar Linnaeus, 1758 | species | 146,176 | 83,343 | Jun–Jul | June | the Netherlands |
| Eastern tiger swallowtail | Papilio glaucus Linnaeus, 1758 | species | 127,549 | 207,099 | Jul–Aug | March | the United States |
| Black swallowtail | Papilio polyxenes Fabricius, 1775 | species | 118,300 | 142,960 | Jun–Aug | March | the United States |
| Common buckeye | Junonia coenia Hübner | species | 95,263 | 109,984 | Jun–Sep | November | the United States |
| Silver-spotted skipper | Epargyreus clarus | species | 95,171 | 106,318 | Jun–Jul | June | the United States |
| Isabella tiger moth | Pyrrharctia isabella J.E.Smith, 1797 | species | 73,490 | 102,854 | Aug–Oct | October | the United States |
| Great spangled fritillary | Speyeria cybele | species | 62,911 | — | Jun–Jul | June | the United States |
| Clouded sulphur | Colias philodice Godart, 1819 | species | 60,685 | 44,706 | Jun–Aug | October | Canada |
| White-lined sphinx | Hyles lineata Fabricius, 1775 | species | 56,270 | 78,500 | Mar–Jun | March | the United States |
| Viceroy | Limenitis archippus Cramer, 1775 | species | 54,362 | 51,860 | Jul–Aug | September | the United States |
| Polyphemus moth | Antheraea polyphemus Cramer, 1775 | species | 53,407 | 80,988 | May–Jul | February | the United States |
| Luna moth | Actias luna Linnaeus, 1758 | species | 47,535 | 69,812 | May–Jul | March | the United States |
| Indian meal moth | Plodia interpunctella | species | 30,882 | 19,730 | May–Aug | January | Germany |
| Rosy maple moth | Dryocampa rubicunda Fabricius, 1793 | species | 26,552 | 34,922 | May–Jun | June | the United States |
| Io moth | Automeris io Fabricius, 1775 | species | 24,812 | 33,351 | May–Jul | December | the United States |
| Hummingbird clearwing | Hemaris thysbe Fabricius, 1775 | species | 21,951 | 30,581 | Jun–Jul | July | the United States |
| Eastern tailed-blue and spring azure | Cupido comyntas | species | 15,109 | — | Jul–Aug | January | the United States |
| Cecropia moth | Hyalophora cecropia Linnaeus, 1758 | species | 13,844 | 20,547 | Apr–Jun | January | the United States |
| Clothes moth | Tineola bisselliella | species | 2,907 | 4,533 | Mar–Jun | January | Germany |
| Underwing moth | Catocala Schrank, 1802 | genus | 364,916 | 151,617 | Jul–Aug | September | the United States |
| Tomato and tobacco hornworm moth | Manduca Hübner | genus | 49,129 | 64,410 | Jun–Aug | January | the United States |
This table is assembled from open data and is free to reuse with a link back to this page. The snapshot behind every Orvik key is published as one downloadable file on the open field data page, with each source's licence terms.
Questions people ask about this
How do I tell a butterfly from a moth?
Look at the antennae. Butterflies have a thin shaft ending in a distinct club or knob; moths have feathery, comb-like or thread-like antennae that taper to a point. Every other rule fails somewhere — plenty of moths fly by day, several are more colourful than butterflies, and skippers rest in a posture that fits neither. The antennae do not fail.
Is that a hummingbird or a moth?
If it is smaller than your thumb, has clear panels in the wings and antennae, and hovers with an audible hum, it is a moth — the hummingbird clearwing or a sphinx moth in North America, the hummingbird hawk-moth in Europe. Hummingbirds have feathers and a beak and are considerably larger. It is one of the most common wildlife misidentifications there is.
What is the difference between a monarch and a viceroy?
Size and one line. The viceroy is noticeably smaller and has an extra black line curving across the veins of the hindwing that a monarch does not have. Its flight is faster and more erratic, while a monarch glides on flat wings. Both are unpalatable to birds, which makes this Müllerian mimicry rather than the Batesian mimicry the older textbooks describe.
Why do moths fly around lights?
Not because they are attracted to them in the ordinary sense. High-speed video published in 2024 showed that moths near a lamp turn their backs to it — flying insects use the bright sky above to stay upright, and a bright point source on the ground breaks that reference and sends them into an endless banking turn. It is disorientation, and it stops them feeding, mating and pollinating all night.
What should I plant to attract butterflies?
Nectar plants bring adults through; host plants make them stay and breed. Milkweed is the only thing monarchs will lay on. Parsley, dill and fennel support black swallowtails. Oak supports several hundred moth species by itself. Violets, willow, cherry and nettles each support specific groups. Then avoid insecticides, leave leaf litter over winter, and accept chewed leaves as evidence it is working.
What are the huge green moths with tails?
Luna moths, in eastern North America — pale sea-green with long sweeping hindwing tails and a translucent eyespot on each wing. The adults have no mouthparts and live about a week, existing only to mate. The tails are not decorative: they spin in flight and disrupt bat echolocation, which measurably improves survival.
How do I get rid of moths in my wardrobe?
Clothes moths are tiny plain golden-buff moths that scuttle rather than fly to a light, and the damage is done by the larvae in wool, silk, cashmere and feathers. Empty the wardrobe completely, vacuum every crevice, wash or freeze affected items for at least 72 hours, and store clean garments sealed — moths lay on soiled fabric preferentially. Pheromone traps monitor the population and will not clear it on their own.
Still not sure? Point a camera at it
A filter narrows species down to a shortlist. Orvik reads the photo itself and names the species, with the look-alikes ranked underneath so you can check the call yourself.