White Admiral

The White Admiral is a brushfoot butterfly (family Nymphalidae) representing the northern form of Limenitis arthemis, a species that also produces the very differently patterned Red-spotted Purple form in the southern part of its range. The two forms meet and interbreed across a broad hybrid zone spanning the northern United States and southern Canada, making this species a notable example of regional color-pattern variation within a single species.

Found in boreal and northern mixed forests, the White Admiral is closely tied to birch, aspen, poplar, and willow trees, which serve as caterpillar host plants. Its bold black-and-white pattern makes it one of the more conspicuous and easily identified large butterflies across its northern range.

As a member of the admiral group, it shares its genus with the Viceroy and Red-spotted Purple, all known for powerful gliding flight and a tendency to feed on tree sap and other non-floral food sources rather than relying heavily on flower nectar.

• Wings are dark blackish-brown above, crossed by a broad, bold white band running across both the forewing and hindwing.
• A row of small orange-red and blue spots may be visible near the outer wing margins, more prominent on the underside.
• No tails on the hindwing; wing margins are smoothly rounded.
• Strong, broad-winged build typical of admiral butterflies.
• Lookalikes: the Red-spotted Purple (southern form of the same species) lacks the white band entirely and instead shows iridescent blue coloring; the Viceroy has a white band too but is orange rather than black-brown and has a distinctive black line crossing the hindwing veins.

Found across the northern United States, including New England, the upper Midwest, and the Rocky Mountain region, and widely through Canada into boreal forest zones. It occupies mixed and deciduous forests, forest edges, and wooded corridors along streams, particularly where birch, aspen, poplar, and willow are present. Adults fly in a single main period during summer in the coldest parts of the range, with activity generally from June through August.

Adults have a strong, gliding flight pattern typical of admiral butterflies and often perch on tree foliage at eye level or higher, descending to feed at sap flows, rotting fruit, damp soil, or animal droppings rather than flowers. Males establish and defend perching territories along forest edges and trails, chasing off rival males and other passing insects. Caterpillars feed on the leaves of birch, aspen, poplar, and willow, and like the Red-spotted Purple form, young caterpillars mimic bird droppings for camouflage. The species is an important component of northern forest-edge insect communities.

Eggs are laid singly at the tips of host leaves. Caterpillars construct a leaf shelter and, characteristic of the species, overwinter as partly grown larvae inside a folded leaf hibernaculum attached to the twig, resuming feeding the following spring. Pupation occurs in a hanging chrysalis. In the cooler northern parts of the range there is typically one generation per year, while slightly warmer areas may support two, with overwintering occurring in the caterpillar stage.