Situated in the Atlantic Ocean hundreds of miles west of the Moroccan coast, the islands of Madeira are home to only about 20 species of butterflies. So in the 1980s, when the Madeiran large white butterfly began to disappear, entomologists took notice. Living exclusively in the island’s wet, mossy laurel forests, the butterflies were found nowhere else on Earth.

Reasons for its decline include habitat loss as well as the arrival of an invasive butterfly that brought viruses with it. An introduced, tiny wasp that breeds in, then kills, caterpillars in this butterfly family may also have contributed. Though entomologists have made serious efforts to find any remaining populations, the Madeiran large white is probably extinct.