Butterflies are not only ephemerally beautiful, they’re crucial pollinators for a variety of important food crops and flowers. And in the western U.S., they’re disappearing—fast.

Over the past four decades, more than 450 butterfly species have declined at an average rate of nearly 2 percent a year, according to a study published today in the journal Science. 

It’s already known that the western monarch has plummeted in population by 99.9 percent and was recently denied protection by the U.S. Endangered Species Act. But the study revealed lesser-known species, like the Boisduval’s blue and California’s state insect, the California dogface butterfly, are heading toward extinction.

“The declines across species are so ubiquitous,” says