Other Common Names
Camberwell Beauty (British Isles), Spiny Elm Caterpillar (larva)
Adult dark brown or purplish-black with yellow borders and blue submarginal spots (1)
Larva black and spiny with a row of eight red patches down the back. (2)
another description: Blackish with abundant white flecking. Black dorsal midline flanked by paired red spots on last thoracic and most abdominal segments. Spines, long and shiny black with short side branches. Prolegs red. [Caterpillars of Eastern Forests
all of North America south of the tundra, south to central Mexico
also occurs in temperate Eurasia
usually riparian areas but may be found almost anywhere that host plants occur, including woods, openings, parks, and suburbs
One of the earliest butterflies seen in spring, due to the fact that it overwinters as an adult.
First-generation adults emerge in early summer, and estivate until fall, when they re-emerge.
Larvae present from June to September in the east [USGS 1
], and from May to July in the west [USGS 2
Larvae eat primarily willow (Salix spp.) but also other trees and shrubs including Cottonwood (Populus deltoides), Trembling Aspen (P. tremuloides), American Elm (Ulmus americana), Paper Birch (Betula papyrifera), and Hackberry (Celtis occidentalis).
Adults feed primarily on tree sap (oaks preferred) and rotting fruit; only occasionally on flower nectar.
Eggs are laid in groups circling twigs of the host plant. Caterpillars live in a communal web and feed together on young leaves, then pupate and emerge as adults in June or July. After feeding briefly, the adults estivate until fall, when they re-emerge to feed and store energy for hibernation. Some adults migrate south in the fall. [Butterflies of North America
: Do not touch the larva; its spines may cause a stinging sensation if handled. The pupa of the Mourning Cloak is harmless - unlike the pupa of tent caterpillars (Malacosoma
species), which may cause an allergic reaction on the skin if handled by allergy sufferers or individuals with very sensitive skin. See Auburn site
for more information.
Butterflies through Binoculars (1)
Butterflies of North America
live adult image plus description, biology, seasonality, food of larva and adult, habitat, range, references, US distribution map
Caterpillars of Eastern Forests
live larva image by Bob Wilson, plus description, foodplants, seasonality, life cycle (USGS)
Caterpillars of Pacific Northwest Forests and Woodlands
live larva image by Jeffrey Miller, plus description, foodplants, seasonality (USGS)