Where Do Butterflies Go In Winter?
Where do butterflies hang out in the winter?
Do all butterflies die?
Do all butterflies fly south?
The answer is simple: it depends upon the species of butterfly about which you are asking. Some
enter diapause, freeze, and live through temperatures well below 32 degrees F.
Butterflies can fly and feed safely in temperatures above 55 degrees Fahrenheit. Like all insects,
their bodies contain chemical compounds known as glycols, which help them endure cold weather.
The glycerol in their body prevents ice crystals from forming. If ice crystals were to form, they would
rupture cells and the butterflies would die. Once the snow starts falling however, they'll need a plan
to survive harsh winter conditions!
Butterfly Overwintering Strategies
Two-way migration: Adult migrates from Wisconsin to Central Mexico
Small migration: Adult migrates from Wisconsin to southern US
Immigrant: Adult migrates into Wisconsin from warmer areas and don't fly south in winter
Adult Butterfly: Hibernates overwinter as an adult butterfly
Eggs: Eggs laid on stems, twigs or foot plants overwinter in diapause
Caterpillar: Caterpillars make nests on the base of plants and hibernate until spring
Chrysalis: Caterpillars shed their last skin, form a chrysalis and enter diapause.
Even though most butterflies have a short life span — ranging from a week to a month — some do
live longer. Many of these species migrate to warmer climates when it gets cold.
If don’t cut down your faded plants in the fall and leave them until temperatures warm in the spring,
they can survive the winter and emerge in your garden! In spring, when longer days and
temperatures warm, butterflies come out of winter diapause.
Monarchs, which may live up to 9 months and travel long distances, provide stiff competition. They
are unique in that they are the only butterfly that makes a 2-way migration, much like birds.
Around October when temperatures drop and food sources decline, the monarchs will travel
3,000 miles or more to their overwintering sites.
West of the Rockies, they go to small grove trees in California near Santa Cruz and San Diego.
East of the Rockies, millions of monarchs find their
way to their winter sites in Mexico and the Michoacán highlands.
Butterflies survive the winter as chrysalis.
Some butterflies hibernate during the colder months, although this isn't strictly true; actually, they
enter a period of dormancy, although the effect of sleeping through winter is the same.
do this in several ways: as an egg, larva, chrysalis or in adult form, dependent on species.
isn't simply a random choice or a technique to keep warm, but is a way of ensuring that the insect's
awakening in the spring corresponds with the peak availability of its main food source.
Most butterflies lie dormant in larval stage, while pupation is the next most common strategy.
and adults come next in order of commonality, although some species are able to overwinter in
more than one form.
Diapause is the delay in development during periods of adverse environmental conditions. The
strategy is a means of surviving predictable, unfavorable environmental conditions.
Butterfly Overwintering Strategies: The Details
Butterflies that remain in cold-winter areas as adults find safe places to rest, like cracks in rocks or
tree bark, and enter a state known as diapause. This is essentially a kind of hibernation for bugs,
where butterflies shut down all their non-essential systems like reproduction and slow their
metabolism dramatically. Special chemicals in their bodies work as anti-freeze, and the butterfly
remains dormant until warmer weather arrives. These are usually the last butterflies to be seen in
an area each fall, and the first to reappear in the spring. For example:
Compton Tortoiseshell (Nymphalis vau-album)
Eastern Comma (Polygonia comma)
Gray Comma (Polygonia progne)
Milbert's Tortoiseshell (Nymphalis milberti)
Mourning Cloak (Nymphalis antiopa)
Question Mark (Polygonia interrogationis)
Perhaps the most vulnerable species are those who spend the winter as eggs, usually laid in late fall
in the leaf litter at the base of the host plant. These eggs will hatch in the spring when the host plant
has put on new growth. For example:
Banded Hairstreak (Satyrium calanus)
Bronze Copper (Lycaena hyllus)
Coral Hairstreak (Satyrium titus)
Edward's Hairstreak (Satyrium edwardsii)
European Skipper (Thymelicus lineola)
Striped Hairstreak (Satyrium liparops)
Other species spend the winter as caterpillars, buried deep in leaf litter or soil or rolled
into a shelter of leaves. They also enter a state of diapause. In the spring, these caterpillars don’t
re-emerge until their host plants have begun growing, so many of them use early spring wildflowers
or budding tree leaves as hosts. For example:
Great Spangled Fritillary (Speyeria cybele cybele)
Black Swallowtail Chrysalis
Dreamy Duskywing (Erynnis icelus)
Eastern Tailed Blue (Everes Comyntas)
Juvenal's Duskywing (Erynnis juvenalis)
Least Skipper (Ancyloxypha numitor)
Butterflies who spend the winter in chrysalis find a sheltered place like overhangs or deep
shrubbery. The chrysalis, like the adult and caterpillar, stops development over the winter months
and contains special chemicals to keep from freezing. When the warmer weather returns and the
days lengthen, development resumes in the chrysalis and the adult butterfly emerges in time for
fresh blooms on nectar plants. For example:
Black Swallowtail (Papilio polyxenes)
Delaware Skipper (Anatrytone logan)
Eastern Tiger Swallowtail (Papilio glaucus)
Giant Swallowtail (Papilio cresphontes)
Hobomok Skipper (Poanes hobomok)
Tawny-edged Skipper (Polites themistocles)
Butterflies and Moths of North America
Southern Wisconsin Butterfly Assn (NABA)
The Butterfly Site