Purple Emperor Butterfly

The Purple Emperor is a large butterfly whose males have areas of iridescent purple on their wings.

The larger females do not have this iridescence, which is how the sexes can be told apart. Its numbers are declining largely due to habitat loss, as the sallow or willow trees where they lay their eggs and the broadleaf trees where they live are being cut down.

5 Incredible Purple Emperor Facts!

• The Purple Emperor is a Palearctic butterfly, which means it’s found in Europe and Asia to the Himalayan foothills and in North Africa. The Palearctic realm is the largest of the ecological realms on earth.
• It belongs to the genus Apatura. Most of the butterflies in this genus are known as Emperors.
• Purple Emperors lay their eggs on the leaves of sallows, or willows, especially Goat and Gray willows. Occasionally, they’ll lay their eggs on poplar trees.
• The Purple Emperor is the second-largest type of butterfly. Only the Swallowtails are larger.
• The Purple Emperor’s conservation status is Not Threatened, even though its numbers are declining. It’s also protected under the Wildlife and Countryside Act of 1981.

Purple Emperor Species, Types, and Scientific Name

The scientific name of the Purple Emperor is Apatura iris. Apatura is probably from the Greek word Apaturia, which means “the deceitful one” and was used to describe several goddesses. The word probably refers to the deceptive nature of the male Purple Emperor’s wings, which only show their iridescence under the right conditions. The other half of the butterfly’s scientific name, Iris, refers to the Greek goddess of the rainbow.

There are five known subspecies of Purple Emperor. They are:

• Apatura iris iris
• Apatura iris bieti
• Apatura iris xanthina
• Apatura iris kansuensis
• Apatura iris amurensis

Appearance: How To Identify Purple Emperor

The wings of the Purple Emperor have a pattern of whites and shades of dark browns. Each hindwing has an eyespot of black, purple, and orange. The underside of the wings of both males and females are different shades of brown marked with white. Males are a bit smaller than the females, with a 2.8 to 3-inch wingspan. The wingspan of the females is 3.15 to 3.54 inches.

The eggs are green or yellow and can be found on the top of sallow leaves. They usually hatch after two or three weeks.

The caterpillars are green with white stripes and dots. They molt or shed their skin five times before they pupate, and during their second molt, they develop horns on their head that make them resemble bright light green slugs. At night they eat the leaves of the willow where they were hatched. It takes about 10 months for the caterpillar to become fully grown, and that often means that they need to hibernate over the winter. A fully grown Purple Emperor caterpillar can be between 1.37 and 2.2 inches long.

When the caterpillar is ready to hibernate, it stops eating, turns brown, and shelters in the fork of a branch. When it wakes up, it starts to eat again, sheds its skin one more time then crawls up to the very top of the tree to pupate. There it creates a chrysalis that is between 1.18 and 1.38 inches long and 0.47 to 0.59 inches wide. It is camouflaged as a willow leaf.

The adult finally emerges in July and has a six-week life span.

Habitat: Where to Find Purple Emperor

The main species of the Purple Emperor seems to be concentrated in several areas in England, especially the forests of southern England. This is where willows and other broadleaved trees are found. Some specimens have also been found in Monmouthshire in Wales.

Subspecies of the butterfly are found in Eurasia. Apatura iris bieti is found in central and western China as well as Tibet. Apatura iris amurensis can be found around the Amur and Ussuri Rivers. The Amur River is the border between Russia and Inner Manchuria, and the Ussuri River runs through Russia and northeastern China.

Diet: What Do Purple Emperors Eat?

The Purple Emperor caterpillar eats the leaves of the sallow tree. The butterfly is unusual in that it doesn’t sip nectar from flowers but takes nourishment from tree sap, the honeydew produced by aphids, and the moisture and salt produced by excreta and dead animals. Purple Emperors are so attracted to dead things that collectors used decaying animal carcasses to bait them, and the males sometimes get run over when they visit roadkill.