The fungus responsible for causing a deadly disease in bat colonies has been observed for the first time in Minnesota, state officials report, marking a slow, yet steady, westward expansion of a fungus nearly always fatal to bats.

White nose syndrome, or WNS, is the disease caused by the fungus Pseudogymnoascus destructans (recently renamed from Geomyces destructans), which kills bats by causing the mammals to rouse during hibernation, depleting the critical energy reserves needed to survive throughout the winter. A fuzzy build-up of white fungus on infected bats' noses gives the disease its name.

The Minnesota Department of Natural Resources reports the fungus, but not WNS, in two state parks. Finding the fungus is alarming because a bat colony infected with WNS is almost certainly doomed; WNS is an effective bat-killer, with mortality rates in some colonies exceeding 90 percent. Nearly 6 million bats in North America have been killed by WNS.

Only a few Minnesota bats have tested positive for the fungus, the presence of which was confirmed in Soudan Underground Mine State Park and Forestville/Mystery Cave State Park, but if the story progresses as it has in other states, WNS will be present in Minnesota bat colonies within two or three years, the Minnesota Department of Natural Resources (DNR) reported.

"This is bad news for an important mammal in our ecosystem," said Steve Hirsch, director of the DNR's Ecological and Water Resources Division, which oversees the agency's non-game wildlife program. "We're prepared with special protocols to help keep the fungus from spreading."

Since its discovery in New York during the winter of 2006-2007, WNS has rapidly spread through the Eastern U.S. and Canada and continues to move westward.

Minnesota DNR officials discovered the fungus in sampling exercises conducted in 2012 and 2013. A recent sampling found that of 47 bats, four tested positive for the fungus.

There are seven species of bats found in Minnesota, four of which hibernate during the winter and have the greatest chance of being infected by WNS.

Bats are important players in the overall health of ecosystems, feasting on insects and keeping populations in check. Minnesota farmers saved $1.4 billion in pest control fees thanks to hungry bats in 2011, the DNR reported.

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