Milbert's Tortoiseshell

Fascinating facts about the Milbert's Tortoiseshell

• A wingspan of just 4.2-6.3 cm, yet its bold pattern reads like a painted flag. The forewing tips are squared off, giving the wings a crisp edge. The upperside is black with wide orange submarginal bands that fade to yellow near the inner edge, while narrow black marginal borders frame each wing. Occasionally the hindwing sports tiny blue spots.
• Milbert's tortoiseshell blankets the entire North-American continent, from the tundra-border of Alaska and Canada down through every western state and most of the east. This continental spread means the butterfly can be found in wet pastures, marshes, trail edges, and roadside verges wherever moisture gathers.
• From May through October the species squeezes out two full broods, each female laying up to 900 eggs in a single clutch on the undersides of host-plant leaves. Early-instar caterpillars hatch together in a communal web, before later instars break away to feed alone.
• Caterpillars of Milbert's tortoiseshell are picky eaters, feeding on nettles such as stinging nettle (Urtica dioica) and tall nettle (Urtica procera), as well as clearweed (Pilea pumila). As adults they sip a varied cocktail of nectar from thistle, goldenrod and lilac, while also drinking plant sap, rotting fruit, and even dung.
• A quick-flitting butterfly, Milbert's tortoiseshell darts along woodland roads and often pauses on trees or rocks, spreading its wings in a flash of orange and black. Adults sometimes gather in small congregations to hibernate. Remarkably, they have been observed mating in low-elevation watercourses even in arid regions.

Sources

Every fact above was checked against these pages, and kept only where one of them states it.

• Wikipedia

At a glance

About the Milbert's Tortoiseshell

In the warm, golden light of a sun-drenched meadow, the Milbert's Tortoiseshell butterfly dances across the landscape, its delicate wings beating in a hypnotic rhythm as it flits from flower to flower. With a subtle elegance, it navigates the intricate tapestry of its natural world, its mottled browns and oranges blending seamlessly into the surroundings as it searches for the sweet nectar that sustains it. As it alights upon a velvet-soft petal, its beauty is revealed in all its glory, a masterful blend of form and function that has evolved over millennia to create this remarkable, ephemeral creature.

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