Emerald ash borers have invaded Lakewood Cemetery, one of the state's most famous resting grounds, and two more sites in St. Paul.

That brings the total number of infested areas of the Twin Cities to eight as the invasive insect continues its march across Hennepin and Ramsey counties, said Mark Abrahamson, entomologist for the Minnesota Department of Health. The other two new sites, announced Friday by the state Department of Agriculture, are near Lexington Parkway and Jessamine Avenue, and along Pig's Eye Lake Road, across the Mississippi River from the St. Paul Downtown Airport.

"We've known all along that this is not something we can stop," Abrahamson said.

The good news is that the new infestations are within the existing Twin Cities quarantine zone, where state and local officials are acting to slow the spread of the bug. There are now four counties in the state in quarantine -- Ramsey, Hennepin, Houston and Winona.

The emerald ash borer, an invasive beetle that threatens Minnesota's nearly 1 billion ash trees, was first found in the state in St. Paul in May 2009. Since then, thousands of ash trees have been taken down while others have been treated with insecticides to try to thwart the beetle's advance. The Department of Agriculture has also released predator wasps in the fight to curb tree losses, which Abrahamson said offers the greatest hope for fighting the insect in rural areas in southeastern Minnesota.

Lakewood Cemetery, just east of Lake Calhoun, has 720 ash trees out of many thousands of trees on its 250 acres, said Ron Gjerde, president of Lakewood.

"We weathered Dutch elm, and we'll weather this one as well," he said.

The bugs were found in two trees for certain, and another is likely to be infested, he said. Those will be taken out immediately, and over time the remaining ash trees will be removed and replaced with more varieties, he said.

"We look at this as an opportunity to introduce new species and varieties, and not have this monoculture," he said. "When you get something like this, it just wipes them out."

With 125,000 or so monuments and markers, the cemetery has long been popular with visitors, not only for paying respects to the dead, but for the parklike grounds that include 11 miles of wide and winding roads and an 8-acre lake. Among those buried there are former Vice President Hubert Humphrey, U.S. Sen. Paul Wellstone and entertainer Tiny Tim.

Foresters in Minneapolis and St. Paul notified the Agriculture Department of the likely infestations, which were confirmed this week. They were spotted because of heavy woodpecker feeding, an indication that the trees were loaded with bugs. Like most such discoveries, the trees have probably been infested for three to four years.

Staff writer Paul Walsh contributed to this story.