Read this good editorial about White Nose Syndrome:
It is difficult to imagine that an entire species, whose numbers are historically very large, could actually disappear. It is even more difficult, but equally unpleasant, to imagine how their disappearance might change an entire ecosystem.
The sky at dusk used to be filled with those predators, each one eating its body weight in insects nightly. Without them, the balance of nature will be changed, with potentially significant impact on agriculture and forestry, which have always depended — almost without knowing it — on the role of insectivorous bats.