Seeking to halt the spread of a disease ravaging bat populations in the Northeast, the Pennsylvania Game Commission laid down the law: All bats collected by wildlife rescuers - regardless of whether they were sick or injured - would have to be euthanized.

The order, issued in response to white-nose syndrome, a highly contagious fungal disease, came just before the busy spring season when baby bats take flight. It has angered bat advocates, who consider the Game Commission's response extreme.

"It's a draconian approach," said Laura Flandreau, a volunteer from Chestnut Hill who launched a petition drive urging Gov. Rendell to persuade the commission to lift the ban. She says none of the other eight states where the disease has been found has banned rescue and release efforts. In New Jersey, she said, efforts are under way to treat infected bats in a research facility.

But Game Commission officials say they issued the bat-release ban to protect thousands of bats from the fatal and, so far, untreatable disorder.

"Given that white-nose syndrome has claimed thousands of bats, if a sick or injured bat is released, it would be adding to the problem," commission spokesman Jerry Feaser said.

Concern about the economic and health costs of this fast-spreading disease prompted congressional hearings Thursday to explore the public-health, environmental, and economic implications of white-nose syndrome. The disease, which so far is found only in cave bats, has turned up in states from New Hampshire to West Virginia, decimating colonies in some areas.

Delegate Madeleine Z. Bordallo (D., Guam), a member of the House subcommittee on national parks, forests and public lands, said Thursday that, left unchecked, white-nose syndrome could bring economic and ecological disaster, given the vital role hungry bats play in curbing disease-carrying insects.

"Bats are nature's best control of insect populations, as a single bat can eat its entire weight in insects in one night," Bordallo said in a statement. "Their decline will likely have far-reaching ramifications for both agriculture and public health."

Lisa Williams, a Game Commission biologist, said the reasons for the Pennsylvania order were many: The disease is difficult to recognize; there are no test, no treatment, and no cure; and it has spread from one bat species to another.

"We are trying to slow the spreading of a disease that has been leapfrogging down the Appalachian range," she said.

The disease is still confined in Pennsylvania to four counties: Lackawanna, Luzerne, Centre, and Mifflin.

In New Jersey, volunteers are being sought to count the state's bats this summer. The Conserve Wildlife Foundation of New Jersey, which is organizing the census, says the count is crucial to determine how many bats have died from the disease.

Pennsylvania and New Jersey are among 12 states that will share in $1.4 million from the U.S. Fish and Wildlife Service to study the disease, which has killed record numbers of bats in New England since 2006, in some cases wiping out 90 percent of the population colonies. The first bats tested positive for white-nose syndrome in Pennsylvania in January, and a month later dead bats were turning up by the hundreds in Lackawanna County. The goal of the research, say Game Commission officials, is to find the cause, and determine how it spreads and whether it can be contained.

Members of the small bat rehabilitation community - eight people in all, licensed through the Game Commission - say the commission's euthanasia order does not consider differences in species or the threat that killing the animals could pose. Tree bats, for instance, are not known to have the disease, and other species, such as the Indiana bat, are endangered.

"I don't think it's a good idea," said Deb Welter, a licensed bat rehabilitator who runs the Diamond Rock Wildlife Rehabilitation Clinic in Malvern. "We are the bats' best chance, and the bats we take in are not implicated in white-nose."

Game Commission officials, who have instructed the rehabilitators to euthanize the bats and ship them to Harrisburg for study, say some bats will have to be sacrificed to help find a cure.