Now that the emerald ash borer has been found in surrounding counties, Philadelphia is on high alert for a pest capable of destroying trees.


The insect is expected to migrate to the city within a year or so, experts said.

But the borers can be stopped from snacking on ash trees, according to Chris Miller, president of the area chapter of the International Society of Arboriculture.

"There are chemical treatments that can be applied to the trees in myriad processes," Miller said. "Some are soil-injected, some are soil-drenched, and some are injected right into the tree."

Treatments protect trees for one or two years. Unfortunately, he said, no natural options are available.

Even if the insects attack your trees, it's possible to halt their advance as long as you begin treatment before more than 20 percent of the tree becomes infested.