Life flutters by quite quickly for these beautiful winged insects. The longest lived adult butterflies live for nine months to a year, but the average lifespan for the majority of species is just two to four weeks.
Multiple factors can affect a species’ average lifespan. For example, monarch butterflies typically live between 2-6 weeks, but it varies from generation to generation. Some generations also migrate and hibernate, which can more than double the lifespan. Other migratory species like the painted lady live for only two weeks.
Some of the longest-lived butterflies, such as the mourning cloak, spend their winters in the tropics before mating in the spring. Others, like tortoiseshells and anglewings, hibernate through cold-climate winters in the holes in trees of man-made structures.
Some small species live no more than a week, while predators and other threats can significantly shorten the lifespan of others.
All of this, however, accounts only for the last of four stages in the life cycle of butterflies, which start as an egg. This hatches into a larva (or caterpillar), which itself turns into a pupa or chrysalis. Often hanging from a leaf, the chrysalis then undergoes complete metamorphosis into a butterfly, a process in which most of the cells in the insect’s body are broken down and rebuilt.
The complete life cycle of butterflies can vary significantly from species to species. Most eggs hatch within a week or two, although some species overwinter as eggs.
How long do caterpillars live for?
Once hatched, caterpillars usually live two to five weeks, although this varies depending on the species and the time of year it’s born. It’s thought this is the most dangerous stage in the insect’s life cycle, with high mortality due to predators, weather conditions and disease.
During this relatively short period, caterpillars famously eat a lot. They multiply their body mass several thousand times, shedding their exoskeletons as they outgrow them. This can happen a number of times before they pupate, when they form a chrysalis and transform into an adult butterfly.
How long do caterpillars spend in the cocoon?
It’s actually a common misconception that butterflies spin a silk cocoon around themselves, whatever certain childhood stories told you. That’s more commonly moths, although a handful of butterfly species do it too. Instead, most butterfly caterpillars pupate by hardening into chrysalises, which serve as protective shells as the insects mature into adults.
This complex stage lasts just 10-14 days in most species, during which the larva body liquefies and is rebuilt as a butterfly. In some species, found in extreme environments, butterflies can stay inside their chrysalis for years, waiting for favourable temperatures or other conditions.
Because temperature is one of the main triggers for this stage of the life cycle to end, butterflies that form their chrysalis inside human dwellings can emerge early, prompted by central heating.