This Butterfly May Have Been the First Insect Driven Extinct by U.S. Urbanization
The beautiful Xerces blue butterfly was a distinct species, according to a new study. It hasn t been seen alive since 1943.
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Photo: Field Museum
Scientists say they’ve confirmed a decades-old suspicion about the loss of the Xerces blue butterfly in the U.S by the 1940s. Based on genetic analysis of a 93-year-old specimen and others, they say the Xerces blue really was a distinct species of butterfly, rather than a sub-group of another existing species, as some scientists have speculated. If true, it would reaffirm the end of the butterfly as the first known insect extinction in the U.S. tied to urbanization.
As the first North American insect to go extinct due to humans, a blue butterfly has become an icon for insect conservation and what happens when humans destroy habitats without thought for the creatures living in them.
The last of the Xerces blue butterflies fluttered through the air in San Francisco in the early 1940s. Now, they can only be seen in glass displays at museums.
These periwinkle pearly-winged insects lived in the coastal sand dunes along San Francisco and were first characterized by scientists in 1852. When urban development swept through this part of California, the sandy soils were disturbed. This caused a ripple effect, wiping out species of the plant the Xerces caterpillars used. The habitat change was too great for the Xerces blue butterfly, and the species went extinct.
As the first North American insect to go extinct due to humans, a blue butterfly has become an icon for insect conservation and what happens when humans destroy habitats without thought for the animals living in them.
The last of the Xerces blue butterflies fluttered through the air in San Francisco in the early 1940s. Now, they can only be seen in glass displays at museums.
These periwinkle pearly-winged insects lived in the coastal sand dunes along San Francisco and were first characterised by scientists in 1852. When urban development swept through this part of California, the sandy soils were disturbed. This caused a ripple effect, wiping out species of the plant the Xerces caterpillars used. The habitat change was too great for the Xerces blue butterfly, and the species went extinct.
Credit: Field Museum
The Xerces blue butterfly was last seen flapping its iridescent periwinkle wings in San Francisco in the early 1940s. It s generally accepted to be extinct, the first American insect species destroyed by urban development, but there are lingering questions about whether it was really a species to begin with, or just a sub-population of another common butterfly. In a new study in
Biology Letters, researchers analyzed the DNA of a 93-year-old Xerces blue specimen in museum collections, and they found that its DNA is unique enough to merit being considered a species. The study confirms that yes, the Xerces blue really did go extinct, and that insect conservation is something we have to take seriously.