Where Prince George's County has used a large scalpel, Howard County is hoping to cure the patient — the indigenous ash tree — with a less invasive chemical treatment. For now, at least, this approach is prudent. Although, officials must be prepared to move quickly if more aggressive measures become necessary.

Prince George's was the entry point in Maryland for the emerald ash borer in 2003, and its larvae have been eating ash trees alive there ever since. After a quarantine failed to stop the spread of this pest, officials there made the call in 2006 to fell every ash tree within a five-mile radius of the infested area.

The insect showed up in Charles County in 2008, and now, there are confirmed sightings here in Howard — specifically in Jessup, Glenwood and Owen Brown. Its appearance in Owen Brown sets up an especially troubling scenario, as Columbia has thousands of ash trees throughout its neighborhoods, many of them already in weakened states because of age and drought.

Howard's plan of attack is to cut down only those ash trees that are infected, give injections to those considered at risk and spray pesticide. This is a more costly approach than cutting down wide swaths of trees, but their environmental benefits — cooling, stemming soil erosion, mitigating air pollution — are worth saving wherever possible.

Of course, if this less radical treatment doesn't take, all the county's ash trees could vanish. So officials will need to monitor the situation closely and be ready to start cutting down more trees in a hurry, in order to save the species in our region.