Introduction to the Red Admiral Butterfly
The Red Admiral butterfly is well distributed and found on five different continents in temperate regions. This butterfly was described by Carl Von Linnaeus in 1758 in Systema Naturae. Host plants include members of the Urticaceae (Nettle Family). In Pennsylvania and the eastern United States they feed primarily on stinging nettle, false nettle, and Pennsylvania Pellitory.

Red Admiral
The Red Admiral butterfly is located throughout the temperate regions of the world and is one of the most common urban habitat butterflies.
Description
Color: Black with orange to red colored stripes and white spots on the top of the forewing. The bottom is multi-colored.
Wingspan: 1.75 to 3 inches.
Active Flying Time: March to October. Butterflies that live in the northern regions will fly south in the winter to find more resources. This butterfly is considered to be a swift flier.
Lifecycle of the Butterfly
Green eggs of the Red Admiral are laid on the top of leaves of a Nettle Family species. These plants are then the host for the caterpillars. This stage takes about 4 to 14 days.
Red Admiral caterpillars are about 1 inch in length and are black with white spots. They make a shelter in a rolled leaf. This stage takes about 2 to 4 weeks.
The caterpillars feed on the leaves of the host plant until becoming a gray-brown chrysalis, which has a green color with gold spots on the top. The chrysalis takes about 1 to 2 weeks to mature.
It then spends about 6 to 20 days as an adult.
Butterflies can have two or three broods in a season.
Credit for lifecycle stage times: Butterflies at Home
Territorial Behavior in Red Admirals
There is some evidence that red admiral butterflies will defend territory from other butterflies and become familiar with the visual features of those territories. They also show a preference for lighter objects to rest on. The occupation of the territories is short-term and there can multiples of them. (Bitzer and Shaw 1979).
The butterflies are most active a couple hours before dusk.
Bitzer, Royce J. and Kenneth C. Shaw. 1979. Territorial Behavior of the Red Admiral, Vanessa atalanta (L.) (Lepidoptera: Nymphalidae). Journal of Research on the Lepidoptera 18(1):36-49.
Habitat and Range
Red Admiral butterflies can be found anywhere in the world where there is a member of Nettle Family present. Generally nettles are found in moist, wetland locations and so are the butterflies. Individuals located in the northern regions will migrate south in the winter in search of food and because they cannot survive the winter, but the migration is not as pronounced as that with the monarchs.
Host Plants
This butterfly uses members of the Urticaceae (Nettle Family) for host plants. In Pennsylvania and the eastern United States this can include stinging nettle (Urtica dioica), false nettle (Boehmeria cylindrica), wood nettle (Laportea canadensis), and Pennsylvania Pellitory (Parietaria pennsylvanica).
Nectar Plants
Nectar plants used include common milkweed (Asclepias syriaca), red clover (Trifolium pratense), aster (Symphyotrichum sp.), and others. However, other sources are preferred including tree sap and fermenting fruit.
For More Information
Butterflies and Moths of North America:Red Admiral
Vanessa atalanta (Linnaeus, 1758)
Wikipedia: Red Admiral Butterfly
Adirondacks Forever Wild: Red Admiral (Vanessa atalanta)
Tehachapi News: Pen in Hand: Red Admiral: the last butterfly of the season is one of the prettiest.


