How Long Do Butterflies Live? Lifespan From Egg to Adult

How long do adult butterflies live?

The winged adult is usually the shortest part of a butterfly’s life. Its main jobs are to mate, lay eggs and, in some species, migrate, and many adults are eaten by birds, spiders or other predators long before they die of old age.

Lifespan varies hugely between species and even between generations of the same species:

These are typical figures for wild butterflies. Individuals vary, and the longest-lived adults spend much of their lives inactive.

The whole life cycle: egg to adult

Butterflies go through complete metamorphosis, with four very different stages. How long each takes depends on the species and above all on temperature.

• Egg. Usually hatches in a few days to two weeks. Some species, such as many hairstreaks, spend the winter as eggs for months.
• Caterpillar. Typically feeds and grows for two to four weeks in summer. Many fritillaries and browns pass the winter as small caterpillars, so this stage can last most of a year.
• Chrysalis. Often one to two weeks in summer. The orange-tip butterfly of Europe spends about ten months as a chrysalis, from early summer to the following spring.
• Adult. From about a week to many months, as in the table above.

A summer monarch shows the fast version. Its egg hatches in about 3–8 days, the caterpillar grows for roughly two weeks, the chrysalis stage lasts about 8–15 days, and the adult lives two to five weeks, roughly two months in total. The painted lady runs through egg to adult in about four to six weeks. The step-by-step story is in how does a caterpillar turn into a butterfly?

At the slow extreme, some Arctic and alpine butterflies, such as certain arctics of the genus Oeneis, need two years to complete one generation because their summers are so short.

Why do some butterflies live for months?

Long-lived butterflies save energy by putting reproduction on hold, a state called diapause. Three main strategies stand out.

Hibernating adults. In cold climates, a few species spend the winter as adults hidden in tree holes, woodpiles, sheds or dense evergreens. The mourning cloak, known in Britain as the Camberwell beauty, emerges in summer, rests through much of the hot season and the winter, and breeds the next spring, for an adult life of about 10 to 11 months. In Europe the brimstone, peacock, small tortoiseshell and comma also overwinter as adults.

Migrants. The late-summer generation of the monarch butterfly does not breed until the following spring. It flies to Mexico or California, spends the winter in dense clusters and lives about eight months, many times longer than its summer parents. Its journey is described in where do monarch butterflies migrate?

Pollen eaters. Heliconius longwings of tropical America, such as the zebra longwing, are unusual in eating pollen as well as drinking nectar. They gather pollen on the proboscis, dissolve out its amino acids and use them to keep producing eggs. Field studies have recorded some individuals living six months or more, far longer than most tropical butterflies.

What affects how long a butterfly lives?

Several factors decide whether a butterfly reaches its full potential lifespan:

• Temperature. Warmth speeds up development and activity, so butterflies in hot weather tend to develop faster and burn out sooner. Cool weather slows everything down.
• Food. Adults need nectar, sap, fruit juice or other sugary food for energy. Plenty of flowers can mean a longer, more productive life.
• Predators and parasites. Birds, spiders, dragonflies, lizards and parasitic wasps and flies kill many butterflies at every stage. Only a small share of eggs, often well under 10% in monarchs, become adults.
• Weather. Heavy rain, storms, drought and sudden frosts can kill adults and damage food plants.
• Reproduction. Producing eggs and courting take a lot of energy. Butterflies that delay breeding live much longer.

How do moths compare?

Moths show the same wide range. Some adult moths, including the luna moth, have no working mouthparts and live only about a week on the fat stored by their caterpillars; see why do luna moths have no mouth? Others, such as the herald moth of Europe, which hibernates as an adult in caves and cellars, can live for many months.

The record for slow development belongs to a moth, not a butterfly. The Arctic woolly bear moth (Gynaephora groenlandica) of Greenland and the Canadian Arctic may need about seven years as a caterpillar, freezing solid each winter and feeding only during the brief summers.

Myths and facts

Myth: Butterflies live only one day. Fact: Most live two to four weeks as adults, and some live for months. The idea may come from mayflies, whose adults often live only a day or two.

Myth: Touching a butterfly’s wings kills it. Fact: Handling can rub off scales and weaken or damage the wings, but a gentle touch does not automatically kill a butterfly. It is still best to watch rather than catch them.