50 Fun Facts About Butterfly

Which sequence lists the stages of a butterfly's life cycle in order?

Egg, larva, pupa, adult: the freshly emerged adult is damp and crumpled, and must pump blood into its wings and let them dry before it can fly; after that it never grows again.

Which tropical American butterfly owes its shimmer to wing ridges, not pigment?

Morpho wings hold no blue pigment: stacked microscopic ridges send back blue wavelengths, and only on the upper side; underneath, the same wings are dull brown with eyespots.

What is the name of the straw-like mouthpart that adult butterflies use for feeding?

Proboscis: it starts as two separate half-tubes that the newly emerged butterfly has to join together, and since it can only suck, the adult lives entirely on liquids.

Kallima butterflies of tropical Asia hide in plain sight because the undersides of their wings resemble what?

A dead leaf: the undersides show dark veins like a leaf's, and individuals vary in colour and blotches as real leaves do, a variety traced in 2022 to a single wing-pattern gene.

What is the pupal stage of a butterfly specifically called?

Chrysalis comes from the Greek khrysos, gold, after the metallic golden sheen on the pupae of some butterflies; most moths instead hide the pupa inside a spun silk cocoon.

What tiny structures cover a butterfly's wings, giving them their color and patterns?

Scales give the wings their colours and patterns, and they are so distinctive that the whole order of butterflies and moths is named for them: Lepidoptera is Greek for 'scale wing'.

What primary sensory function do a butterfly's antennae perform?

Smelling: antennae are often called 'feelers', but they do more than touch; they are the insect's nose, picking up scents drifting on the air.

Adult butterflies take only liquids; besides nectar, which of these plant fluids do some sip for nourishment?

Tree sap and aphid honeydew are the main fare of Britain's purple emperor, a treetop butterfly that also comes down to probe dung and carrion for salts.

What happens to most of a caterpillar's tissues while it is transforming into a butterfly?

Broken down and rebuilt: the caterpillar releases enzymes that digest much of its own body into a kind of soup, and small clusters of surviving cells grow into the adult's eyes and wings.

Which European butterfly scares off birds with a sudden wing flash and a hissing sound?

The peacock lives by bluff: in tests, blue tits killed almost none of the butterflies whose eyespots were intact but most of those with the spots painted out, though it is perfectly edible.

How do most butterflies hold their wings when resting, a quick way to tell them from most moths?

Closed upright over the back is the rule, though it is broken both ways: some skippers rest with their wings flat, while geometrid moths often hold theirs up like a butterfly.

A butterfly's body has three sections; which one carries all six legs and both pairs of wings?

Thorax: this middle section is packed with the flight muscles, and a butterfly can also move its wings simply by changing the shape of the thorax itself.

Besides providing colour, what other function does the covering on a butterfly's wings serve?

Insulation: the wing covering helps the butterfly hold on to body heat, and because it comes away so easily it is also widely believed to help the insect slip free of a spider's web.

Butterflies belong to which superfamily of the order Lepidoptera?

Papilionoidea: phylogenetic work placed the skippers (Hesperiidae) and the moth-butterflies (Hedylidae) inside the superfamily too, making it equivalent to the traditional grouping Rhopalocera.

What do butterflies mainly use the sense organs on their feet for?

Tasting: a butterfly samples a plant just by standing on it, and a female swallowtail drums a leaf with her forelegs to check it is the right kind before laying an egg.

Roughly how many butterfly species are there worldwide?

About 18,500 butterfly species are known, yet they are a small minority of their order: moths make up most of the 160,000 or more described species of Lepidoptera.

The large blue butterfly's caterpillar lives inside the nests of which insects?

Ants: the caterpillar is adopted into a red ant nest and feeds on the brood; the large blue died out in Britain in 1979 and was brought back only once it was clear which ant it needs.

A 2023 DNA study found the first butterflies' caterpillars probably fed on which plant family?

Pea family, the legumes: the same DNA work dates the first butterflies to about 100 million years ago, when a line of night-flying moths took to the day in what is now the Americas.

In most butterfly families, what shape are the antennae?

Clubbed antennae are the quickest way to tell a butterfly from a moth, though not a perfect one: the day-flying sun moths have clubbed antennae too and are often mistaken for butterflies.

In many butterfly species, mud-puddling is restricted to which individuals?

Males: usually only they puddle, and the sodium is thought to be passed to the female at mating as a nuptial gift; in one test, salt-fed males courted harder and mated more often.

What is it called when a harmless butterfly imitates a distasteful species to borrow its protection?

Batesian mimicry is named for Henry Walter Bates, who described it from butterflies in the Amazon rainforest; it works best while the harmless copies stay scarcer than the distasteful species they imitate.

Unlike mammals, most butterflies use which sex-chromosome system?

ZW females, ZZ males: the female has the unlike pair, the mirror image of our XY system; birds use the same arrangement, so in both it is the egg, not the sperm, that fixes the sex.

The word 'butterfly' descends from a compound word in which language?

Old English: the OED's earliest form is butorflēoge, from butor (butter) and flēoge (fly); one theory links the name to the bright yellow male brimstone, and modern Dutch and German use unrelated words.

The world's largest butterfly, Queen Alexandra's birdwing, is restricted to forests in which country?

Papua New Guinea: the birdwing survives in just two pockets of rainforest in Oro Province, hemmed in by oil palm; the 1951 eruption of Mount Lamington may also have wiped out part of its range.

The Homerus swallowtail, the Americas' largest butterfly, survives only in the Blue Mountains and Cockpit Country of which Caribbean island?

Jamaica: the swallowtail once lived in seven of the island's 14 parishes, but a 2017 review found only two strongholds left, and trade in it is banned under CITES Appendix I.

Queen Alexandra's birdwing flies so high that the first specimen, in 1906, was collected how?

Shot down: the collector Albert Meek brought the first female down with a gun, and the specimen still shows the holes; his patron Walter Rothschild named the species the next year.

The hedylids, moth-like butterflies of tropical America, fly mostly at night and have ears tuned to which hunters?

Bats: hedylids carry ultrasound-sensitive hearing organs that pick up a hunting bat's calls, and DNA suggests their ancestors flew by day and took to the night early in the family's history.

The monarch belongs to which butterfly family?

Brush-footed butterflies, the Nymphalidae, keep their tiny front legs curled up against the body, so a monarch appears to stand on only four legs.

Which smaller monarch mimic has an extra black stripe across each hindwing?

The viceroy (Limenitis archippus) is smaller than the monarch and carries a black line across each hindwing; both are distasteful, so each reinforces the other's warning to predators.

Which heart poisons do monarch butterflies store from their food plants to deter predators?

Cardenolides protect most monarchs, yet at the winter roosts black-backed orioles and black-headed grosbeaks eat millions of them a year; the grosbeak is largely insensitive to the poison.

Monarchs from east of the Rockies winter in the mountain fir forests of which country?

Mexico: they cluster by the tens of thousands per tree in high oyamel fir forests, yet none has made the trip before; these monarchs are generations removed from those that flew north in spring.

How can a male monarch be told apart from a female?

Small black scent spots on the hindwings, one on a vein of each, mark the male; females lack them and have thicker black veins. Oddly, the scent seems to matter little in monarch courtship.

Britain's painted ladies seemed to vanish each autumn until researchers showed that they do what?

Fly south at high altitude: radar picked up the autumn exodus far overhead, riding favourable winds, which is why watchers on the ground had almost never seen it.

Many painted ladies that reach Britain each summer descend from butterflies that flew north across which desert?

The Sahara: hydrogen isotopes locked in the wings of painted ladies caught around the Mediterranean in spring showed that many had grown up beyond the desert, in tropical Africa.

The glasswing butterfly's wings are see-through partly because pillars on their surface stop them doing what?

Reflecting light: the pillars, narrower than a wavelength of light and of random heights, cut glare from almost any angle, which helps the butterfly escape a predator's notice.

A threatened swallowtail caterpillar's forked osmeterium emits what?

A pungent smell: the organ stays tucked inside the body until the caterpillar is disturbed, then shoots out, and its vapour has been shown to repel small predators.

The word 'caterpillar' probably derives from an Old North French term meaning what?

Hairy cat: Old North French catepelose joined cate, cat, and pelose, hairy; the English ending was probably reshaped under the influence of piller, an old word for a plunderer.

A caterpillar has a dozen tiny eyes; what kind does the adult butterfly have?

Compound eyes are built from thousands of tiny lens units, so an adult butterfly can watch almost every direction at once and is quick to catch movement, though the image is not sharp.

The 'butterfly effect', in which a wingbeat in Brazil might set off a tornado in Texas, belongs to which field?

Chaos theory grew from Edward Lorenz's weather models; he first spoke of a seagull's wings changing the weather, and the butterfly arrived only in the title of a 1972 talk, supplied by a colleague.

Which Russian-born novelist was also a serious lepidopterist who curated butterflies at Harvard in the 1940s?

Vladimir Nabokov, the author of Lolita, proposed in 1945 that a group of blue butterflies reached the Americas from Asia in waves; DNA work in 2011 confirmed five waves across the Bering Strait.

The word 'metamorphosis' comes from Ancient Greek roots meaning 'after' and what?

Form: metamorphosis joins the Greek meta, 'after' or 'beyond', with morphē, 'form'; insects with a resting pupal stage between larva and adult are called holometabolous.

What is the entomologist's word for a caterpillar's droppings?

Frass comes from a German word for what an animal has eaten; some skipper caterpillars fire their pellets clear of their leaf shelters with a comb-like flap, which may keep predators off the trail.

Monarch caterpillars feed only on which plants, storing their toxins to become poisonous to birds?

Milkweeds are the monarch caterpillar's only food, so the butterfly's fortunes follow the plant: the loss of milkweed from American farm fields to herbicides is a leading explanation for its decline.

Why do males of many butterfly species gather on hilltops?

To find mates: in the behaviour called hilltopping, a summit serves as a meeting point, so males compete for the very top and unmated females fly uphill to them.

Migrating monarchs hold their course across a continent mainly by tracking what?

The sun's position is their compass, corrected through the day by a body clock that turned out to sit in the antennae, not the brain; monarchs without antennae lose their shared heading.

A 2025 study found butterfly numbers had fallen 22% in twenty years across which country?

United States: the 12.6 million butterflies counted showed 13 times as many species declining as increasing from 2000 to 2020, and a separate Midwest study tied such losses most strongly to insecticides.

Which ancient Chinese philosopher dreamed he was a butterfly, then woke unsure whether he was a butterfly dreaming of being a man?

Zhuangzi does not end the story in doubt: between himself and the butterfly, he says, there must be some distinction, and the passing from one to the other is what he calls the transformation of things.

The ancient Greek word for butterfly, psȳchē, primarily meant what?

Soul: the same word gave English 'psychology', and ancient artists pictured Psyche, the soul personified, as a young woman with a butterfly's wings.

Kjell Sandved spent 24 years photographing butterfly wings to find a full set of what?

Alphabet letters: after spotting a perfect letter F on a wing among the Smithsonian's specimens, the Norwegian-born photographer set out to find the other 25.

What do entomologists call each growth stage between a caterpillar's moults?

Instars: a caterpillar grows by shedding its skin, so it gets bigger in steps rather than smoothly; a monarch passes through five instars in about two weeks before it is ready to pupate.