White nose fungus has all but wiped out the population of little brown bats in southern New Brunswick.

Don McAlpine of the New Brunswick Museum has just finished a survey of 10 caves in the region. The numbers have dropped from 7,000 in 2011 to just 22 this spring.

"Many of the sites had no bats, and about half of those were at one site in Albert County," said McAlpine.

"There were a few bats in some of the other sites, but more than half the sites had none."

The fungus attacks the wings, feet and ears of the bats and causes them to lose bodily fluids.

"There's still hope that there will be some individuals [that] will have natural immunity to this fungal infection, and over a period of time populations will recover to some degree," said McAlpine.

"But there's no real evidence of that yet, and there's certainly a good possibility that some of these species could become regionally extirpated or extinct."

The decline is not good news for farmers and foresters, said McAlpine, as the bats eat large numbers of moths and beetles, as well as mosquitoes.