Milbert's tortoiseshell

Aglais milberti

A dark butterfly lit by a blazing orange-and-yellow band.

Family: Nymphalidae (brush-footed)
Wingspan: 1.6 to 2.5 in (4.1 to 6.4 cm)
Flight season: Spring to fall; overwinters as an adult
Range: Northern North America
Caterpillar food: Nettles
Conservation: Secure and widespread

Milbert's tortoiseshell is a dark, chocolate-and-black butterfly crossed by a brilliant band of orange fading to yellow, a startling flash of fire when it opens its wings.

A northern and mountain butterfly, it overwinters as an adult and flies early, favoring sap and flowers alike.

Milbert's tortoiseshell caterpillar — Spiny caterpillars feed in groups on nettles. Matt Muir · CC BY (iNaturalist)

Caterpillars feed in groups on nettles.

Sources

Butterflies and Moths of North America ↗
iNaturalist ↗
Plant associations from GloBI flower-visit records and NPIN larval-host data. Butterfly photographs via iNaturalist (CC BY).

Plants for the milbert's tortoiseshell

Sources