ENVIRONMENT Study: No solution to slow the spread of the Asian beetle

The beetle is concentrated in Michigan, northern Ohio and Indiana.
DELAWARE, Ohio (AP) -- Researchers and the Canadian government say there's no way to stop the spread of an Asian beetle that kills ash trees, valued for their shade, wildlife food and wood for baseball bats and furniture.
The emerald ash borer was found just three years ago in the Detroit area, but researchers suspect it arrived as much as a decade ago. The U.S. and Canadian governments are sticking with a strategy of cutting down swaths of trees to keep it from spreading, but in the past year agreement has grown that the approach will at best slow the insect.
"The eradication efforts may not be eradication efforts. They may be slowing the spread," said Jennifer Koch, a U.S. Forest Service research biologist in Delaware. Others said that opinion emerged at a research meeting last month in Pittsburgh, although some still disagree.
"It looks pretty dismal for our native ashes," if nothing is done, said Vic Mastro, director of the U.S. Agriculture Department's laboratory in charge of detecting and controlling foreign pests. But Mastro still holds out hope the spread can be stopped.
"It's still worth the fight," he said.
Found in Midwest
The beetle is concentrated in Michigan, northern Ohio and Indiana, and southern Ontario, Canada. It advances about one-half mile a year. Small infestations from Michigan nursery trees in Maryland and Virginia are thought to be eradicated. If it uses Ohio or Michigan's Upper Peninsula as a bridge, it could devastate dense stands of ash in forests from Minnesota to Maine.
An estimated 10 billion mature ash trees, mainly in the eastern United States and Ontario, provide dense shade needed by many endangered plant species. In Ohio, the trees make up 10 percent of forests.
Many cities planted ash trees along streets after the devastation of Dutch elm disease.
Ohio agriculture officials announced Thursday the beetle has spread farther east in the state, to a golf course and three other scattered properties near the Ohio Turnpike in Erie County. Money came through this fall for crews to attack spot infestations in Delaware County in central Ohio and Auglaize County in western Ohio.
Technology needed
The Canadian government's position is that the technology and efforts available cannot stop the ash borer's march, a forestry official said.
"It is well established and is much too difficult to detect at low levels, and pesticides do not work well enough to be used in a quarantine context," said Ken Marchant, a forestry specialist with the Canadian Food Inspection Service, which regulates exotic pests.
"It is the general consensus of quarantine experts here that EAB [emerald ash borer] will continue to spread despite past, present and future actions to control it."
In Asia, there are parasites and diseases that thin the population of emerald ash borer. Here, the beetle has killed 100 percent of trees it infested. The beetle's grublike larvae feed on the cells under the bark that the tree depends on to move water and nutrients, starving it.
Research continues
Researchers are studying genetics, insecticides and natural predators -- hoping they can quickly find a way for the trees to coexist, damaged, with the pest. In the worst case, they'll need to breed a resistant tree to replant forests.
The strategy in Ohio and Michigan is to cut and burn ash trees within a half-mile of infestations. But the beetle is known to fly farther than that, said Leah Bauer, a research entomologist for the department's U.S. Forest Service in East Lansing, Mich.
Also, voluntary checkpoints and education campaigns have not stopped campers from moving firewood. Ohio officials suspect the Erie County infestation, which does not adjoin those in neighboring Sandusky County, was started by people moving firewood or live trees from a quarantined area.
"Emerald ash borer is probably out in the environment much beyond the point at which we can detect," Bauer said. "People are not willing to comply with the ban on moving firewood around."
Beating the pest
Ohio is sticking with the containment strategy and believes it can beat the pest, said Melissa Brewer, spokeswoman for the Ohio Department of Agriculture. "We're trying to protect the ash trees in Ohio, and in the nation," she said.
Containment efforts are still worth a try, said Mastro and Dan Herms, an entomologist with the Ohio Agricultural Research and Development Center in Wooster. It would be more costly to cut down dead trees endangering homes and power lines.
"The odds continue to go down with every infestation that's discovered," Herms said. "The battle is won or lost in northern Ohio."