By Zach Howard
BUCKLAND, Mass (Reuters) - White nose syndrome, a devastating disease that has killed more than one million bats in the Northeast, has been found in Maine, the last New England state to discover it, wildlife officials said on Tuesday.
Diminishing populations of bats, an important predator of insects, could have harmful consequences for humans, experts say.
Bats at two sites in Maine's Oxford County that displayed signs of a fungal pathogen linked with white nose syndrome tested positive for the disease, said scientists with the Maine Department of Inland Fisheries and Wildlife.
Until this year, Maine appeared insulated from white nose, although nearby states and Canada were not.
Since its discovery in an upstate New York cave in 2006, white nose has been confirmed in 17 states and four eastern Canadian provinces, and it appears to be steadily trekking westward.
North America's loss of bats, a key predator of mosquitoes, beetles and pests that can harm plants, could cost agriculture at least $3.7 billion a year, according to a study published in the journal Science in April.
Scientists predict the disease could wipe out some bat species in New England within 15 years.
In Maine, susceptible species are big brown and little brown bats, northern long-eared and tri-colored bats and eastern small-footed bats.
"It is possible that bats that winter in Maine spent the summer in contact with bats from WNS-infected sites in other states, and then carried the fungus back with them to their winter hibernaculum (caves and mines that are homes to bats) in Maine," said John DePue, a biologist with the Maine agency.
The syndrome gets its name from a white fungus that settles in tufts on infected bats' muzzles and invades their skin. It causes them to use limited body-fat reserves, retreat deeper into chilly caves or exhibit odd behavior, such as flying in daytime and cold weather, when insects they eat are not found.
Oklahoma is the furthest west the fungal pathogen Geomyces destructans linked with white nose has been detected, while full-blown white nose has gone as far west as Kentucky and Tennessee.
Little brown bats are the ones worst hit so far by white nose nationally, and the endangered Indiana and Southeast-based Gray bats potentially could be most acutely affected as well.
White nose is mainly spread bat to bat, but humans can transport fungal spores via clothes and gear from contaminated sites, such as caves and mines. People can help slow the spread by staying out of sites that are homes to bats.
About a dozen species out of a total 45 U.S. bat species are affected by white nose, which is nearly half of the 26 bat species that are cave-hibernating bats.
In some Northeast caves, 90 to 100 percent of populations have died. About 1,100 bat species exist worldwide.
(Reporting by Zach Howard, Editing by Ellen Wulfhorst and Jerry Norton)