Ailing bats mean more pesticide use in Texas

Tuesday, February 16, 2010

White-nose syndrome has killed so many bats in the United States that media reports warn it could affect agriculture. The reports are based upon a Texas study of eight counties that estimates the loss of Brazilian free-tailed bats would require use of an additional US $121,000-$1.7  million in pesticides to produce the state's cotton crop.

The syndrome is named after a fungus that grows on bats' noses and other membranes in low temperatures.

It disrupts the bat's hibernation, waking it and depleting energy stores. A 2009
New York state survey indicates that only 10 per cent of bats survive in affected colonies.

Experts anticipate the syndrome will spread to Canada and predict it will eradicate the Little Brown Bat, the most common of Ontario's eight species. The Big Brown Bat may be at less risk because it hibernates in buildings rather than caves or old mines, where syndrome-affected colonies have been found.

The Ontario Ministry of Natural Resources and the University of Guelph are monitoring the syndrome but haven't spotted it yet. But Brock Fenton, a University of Western Ontario biology professor who specializes in bats, downplays the impact on farming.

Brazilian bats can live in colonies of 10 million, he explains, and the biggest bat colony he's ever seen here is 3,000. While Little Browns can eat their own weight in insects every night and may chow down on corn borer moths, cucumber beetles or mosquitoes, they prefer easier catches over water, including midges and mayflies.

"There aren't enough of them and they don't eat enough to make a difference" to crop production, he concludes. BF