Ash trees in the region are in jeopardy, one official said.
COLUMBUS (AP) -- A beetle that has killed millions of ash trees in Michigan appears to have been wiped out in Columbus but continues to cause problems around Toledo, officials say.
No emerald ash borers were found this summer or fall in "trap" trees on Columbus' northeast side. Scientists cut bark on the trees to release sap that attracts the beetles, which would have gotten stuck to a substance placed around the trees' trunks.
"Being 100 percent sure it's been eradicated is tough because this pest is so hard to find," said Melissa Brewer, spokeswoman for the Ohio Agriculture Department.
Scientists suspect the fingernail-size, metallic-green insects arrived in cargo ships from Asia about a decade ago.
The beetles have killed an estimated 12 million ash trees in southeastern Michigan and thousands more were cut down to keep the insect from spreading.
They also have spread into the Toledo area and other parts of northwestern Ohio. There are at least 12 sites where all ash trees within a half-mile of an infested tree will be cut down, chipped up and burned.
"The good news is, we have a pretty good idea of where the leading edge of the infestation is," said Dan Herms, an entomologist with the Ohio Agricultural Research and Development Center. "The bad news is, it's at Toledo."
There's a chance every ash tree in the Toledo area will be gone before the insect is eradicated.
"If there's an infestation within a half-mile of your house, they will come in your back yard and cut down your ash trees," Herms said. "If that goes on long enough, there won't be any trees left."
Ash trees will be cut in Maumee State Forest and Oak Openings Preserve Metropark.
"It's important to get the larger trees because they're the major host trees," said Andrew Ware, the state's assistant forestry chief. "That's what we've been focusing on."
The federal government spent $3.8 million to fight the emerald ash borer in Ohio last year, and state officials have requested $11.6 million for 2005. Stopping the insects will cost tens of millions of dollars, but not stopping them will cost billions in damage, Herms said.
While scientists are working on sprays, destroying the trees -- their food source -- appears to be the only effective way to stop the ash borers.
"If it gets past [Toledo]," Herms said, "it will be very difficult to stop."