Sign up for our email newsletter for the latest science news

What's the News: Bats are an economic boon worth approximately $23 billion per year, and possibly up to $54 billion, to U.S. agriculture, a study in today's issue of Science estimates. Their voracious appetite for insects---a colony of 150 brown bats eats about 1.3 million pesky, crop-chomping bugs each year---means that bats function as effective, and free, natural pesticides. How the Heck:

A previous study found that bats saved farmers an average of $74 an acre in pesticides (ranging from $12 to $174 an acre), across eight cotton-growing counties in southeastern Texas.

Using that figure as a jumping-off point, the researchers extrapolated how much the disappearance of bats across the nation would cost per year. They came up with the yearly cost of $3.7 billion to $54 billion, putting their own estimate at $22.9 billion.

That estimate, they point out, just includes money saved purchasing pesticides; it doesn't take into account secondary costs, like the impact of pesticides on the environment.

What's the Context:

Unfortunately, bats are dying at an alarming rate. The mysterious, as-yet-incurable white-nose syndrome has killed over a million bats in the U.S. and Canada since 2006.

Nor is white-nose syndrome all bats are up against: Wind turbines can kill them two different ways.

The Future Holds:

It's not looking good for the bats. White nose syndrome may drive some New England species to extinction within 15 years, and the disease is still spreading.

Nor is there much money going into the hunt for a cure: The U.S. Fish and Wildlife service spent only $2.4 million studying white-nose syndrome last year---about a tenth of a percent of the low-end estimate of bats' economic value---and research budgets for the disease are likely to shrink even further, reports Brandon Kiem at Wired Science.

Reference: Justin G. Boyles, Paul M. Cryan, Gary F. McCracken, and Thomas H. Kunz. "Economic Importance of Bats in Agriculture." Science, April 1, 2011. DOI: 10.1126/science.1201366.

Image: Flickr / longhorndave