Map Araschnia levana

Few butterflies in the world are as confusing as this one — not for any difficulty in identification, but because the spring and summer generations look so utterly different from each other that they were originally described as two separate species. The spring form is bright orange with black markings; the summer form is dark brown and white, resembling a small white admiral. This dramatic seasonal shape-shifting, triggered by day length and temperature, is called seasonal polyphenism, and it remains one of the most striking examples known in any insect.

Flip the butterfly over and the common name makes immediate sense: the intricate web of white lines on the dark underside looks remarkably like a detailed road map — a tiny, ornate chart of somewhere worth visiting.