The killer has a scientific name, but its gruesome behavior is familiar to anyone who’s read a horror story.

Pseudogymnoascus destructans is essentially a pathogen’s version of a vampire. It lurks in the dark, sneaks up on its victims and snuffs them out quietly, with hardly a squeak. The cold-craving fungus causes white nose syndrome, a disease that has wiped out millions of bats as they hibernate, littering caves with their corpses.

Yet a study published this week reveals the killer’s glaring weakness: Ultraviolet light destroys it.

“It’s something that has evolved for millions of years in the dark. Its ability to repair damage caused by UV light … seems to be entirely lacking in this fungus,” said Daniel Lindner, a pathologist for the U.S. Forest Service. “I’d go as far as to say it’s a vampire fungus. It doesn’t go up in a puff of smoke, (but) it’s gone down an evolutionary path so far that it’s really a creature of the dark.”

After nearly a decade of studying the pathogen that has destroyed 90 percent of bats in some areas, researchers’ discovery is potentially a breakthrough. Scientists have followed a trail of dead bats across much of the United States and Canada as white nose syndrome went unchecked in caves and mines. Now there’s a tool that might finally turn the tables.

But developing the tool will take time. Lindner, one of the study’s four authors, said afflicted bats are being treated with quick pulses of light to determine whether that can destroy the fungus. The first results will not be known for months.

Lindner and his co-authors — Jonathan Palmer, a Forest Service research biologist, and Kevin Drees and Jeffrey Foster, both research scientists at the University of New Hampshire — worked for three years before they identified the pathogen’s basic flaw.

Palmer was in the midst of compiling a mind-numbing mass of data from sequencing its genome when he realized there was a gap in its string of DNA. “Fungi are somewhat easy to sequence, as opposed to a person, but still you end up with this data overload problem,” he said.

“It was a needle in the haystack, trying to figure out what it means. It took a couple of years to tease out,” Palmer said.

Pseudogymnoascus destructans is ancient, much older than mummies. It evolved millions of years ago with bats in Eurasia, which still appear to be unaffected by the disease. But after the fungus made its way across the Atlantic Ocean, North American bats appeared to have no natural defense. It attacked them while they tried to hibernate, causing them to burn fat stores they needed to survive through winter.

If the carnage continues, bats — little brown bats in particular — are headed for extinction.