Milbert Tortoise Shell
Aglais milberti
Summary
The colors to look for on this medium-sized butterfly are dark chocolate brown and orange, with a frill of black along the wings’ bottom edge. This strong flier flits rapidly about its territory, and regularly alights on the ground, a rock or a tree, where it can be spotted basking with wings spread wide to soak up the sun. Adults visit many flowers for nectar, but show special interest in autumn-blooming asters and goldenrod. Like others in its family, this butterfly overwinters as an adult in sheds, woodpiles, or under bark.
More Details
FAMILY
Nymphalidae (Brushfoots)
IDENTIFICATION
Wingspan 1.65 – 2.48 in. Wings with broad band of orange. Orange bar at end of cell on forewing. Marked like no other butterfly in Pennsylvania.
HABITAT
Woodland edges, moist meadows, and streamsides
LIFE CYCLE
Egg: Round green eggs are laid in clusters. Caterpillar: Adorned with spiny projections that serve as a deterrent to predators. Young caterpillars feed together in a web. Pupa: Adopts a brown camouflage that blends into its surroundings. Adult: Overwinters as an adult. Uncommon.
HOST PLANTS
Stinging Nettle (Urtica dioica)
Ecosystem Connections
The host plants for Milbert’s tortoiseshell larvae are nettles, where young caterpillars create a tent and feed in groups. Adults play a role in pollination, and all life stages provide food for predators.