Bats have lived down their vampire mythology – just in time to disappear.

White nose syndrome threatens to wipe out five of Pennsylvania’s six bat species, according to bat biologist DeeAnn M. Reeder of Bucknell University, Lewisburg.

Bats are dying by the hundreds in Pennsylvania outside caves where they hibernate. A white fungus is the suspect.

Reeder and Pennsylvania Game Commission biologist Greg Turner confirmed white-nose syndrome in Pennsylvania a year ago at a Mifflin County cave. They counted six live bats. The cave usually has 1,000.

Turner is keeping an eye on caves across the state, including one in Franklin County and another in Bedford County, but the fungus hasn’t showed up there yet.

“Presumably it will get there within the next year,” Reeder said.

Biologist Jim Hart said a devastated bat population will cost farmers and impact water quality.

Bats sometimes eat their own weight in insects in a single day. That’s about 2,000 mosquito-sized bugs.

“They are worth their weight in gold,” said Hart, a mammalogist with the Western Pennsylvania Conservancy. “They take an enormous toll on agricultural pests. If they all disappear, that’s going to be a pretty bad scenario.”

Birds won’t immediately eat all of the extra bugs, according to Hart. Populations of farm pests will increase quickly and farmers will respond by applying more pesticides, some of which will find their way to streams.

The U.S. Fish and Wildlife Service suspects cavers have been inadvertently spreading the disease and has advised closing all non-commercial caves in the state to humans. Should all bat species be listed as endangered, caves could be closed to caving, Hart said.

The fungus also is believed to be spread from bat to bat.

Wildlife biologists estimate that the disorder has killed 750,000 bats in the Northeast since it was first discovered in 2006 in New York. An estimated one million bats overwinter in hundreds of hibernacula across Pennsylvania.

Science is ill-prepared for the crisis.

“In general, we don’t know enough about normal bats to know what’s different in sick bats,” Reeder said.