Kiss Your Ash Goodbye?

By now many Southeastern Pennsylvania residents have noticed bright purple boxes hanging along roadsides. Tree lovers may have noticed that those gizmos are hung in ash trees. They are traps designed to detect the arrival of the latest invasive tree pest, Emerald ash borer (EAB), Agrilus planipennis.



Emerald ash borer has been moving east from Michigan since 2002, where is it was first detected in the U.S. EAB is native to Eastern Russia and Asia and was probably introduced on wooden pallets or other wooden packing material.
It was found on the western border of Pennsylvania in 2007 and central PA in 2009. For more info about EAB see this Penn State site. States that have lived with the infestation longer, such as Ohio, also have excellent information. For some nice color pictures of the insect and its damage, see this.

I have very little good news about this insect but read on if you are still interested.

Good news… No Emerald Ash Borers have been detected in Southeast PA as of June 21, 2011.
Bad news… Expect a detection any day now.


Good news…Only ash trees will be affected by this insect.
Bad news…. EAB has killed about 40 million ash trees so far. All ash species are susceptible and EAB kills most ash in its path.


Good news… Ash trees make up small percentage (3-4%) of the trees in Pennsylvania.
Bad news… Southeast Pennsylvania has a much larger percentage of ash. Ever since I learned about EAB, I have been impressed with the number of ash in Bucks County. See this to learn what ash looks like. I blogged about this in 2008.


Good news…. Ash can be protected from EAB infestation. Several insecticide options are available. Arborists are prepared to do the work. Do-it-yourself is possible.
Bad news…. Insecticide applications ain’t cheap and will require annual re-treatment with most products. Also, it will be impractical to treat all but the most important ornamental trees. Woodland ash are going to be toast.


Good news…Ash makes excellent firewood.
Bad news… The cost of tree take-downs is significant


Good news… Woodpeckers eat EAB larvae.
Bad news… Not fast enough to prevent tree death.


Good news…Entomologists are working to introduce parasites and predators to control EAB
Bad news.. .This stuff takes a long time and the beast is at the door.


Good news....Land Grant Universities in Ohio, Michigan, Illinois, Wisconsin and our Own Penn State have posted a tremendous amount of excellent EAB information. See above.
Bad news… none of it will stop expanding range of this destructive insect




Good news…. Many wonderful tree species remain in our woods and landscapes
Bad news… You can kiss you ash goodbye.

Watch Your Ash

The other day I found myself taking a cross country walk through suburban Doylestown Township. From Cross Keys to Delaware Valley College, if you know the territory. I was trying to stay out of the sun so I stuck to the side streets, looking for shade. I found a lot of shade but as I proceeded though one particular development I noticed something disturbing. Almost every tree I walked under was ash. Green Ash is a great tree -tough as nails and well adapted to our region. Not much for flowers or fruit but it's a good choice for shade. Or it was.

As you may have heard, there's a new pest in Pennsylvania called Emerald Ash Borer. Just about one year ago the pest was found on the western Pennsylvania border. It traveled east from Ohio. The original infestation in the United States was found in Michigan in 2002 where it has devastated more than 30 million ash trees. Who knows how long it will take for this boring beetle to reach our end of the state but experts agree, it is just a matter of time. The larval stage of this insect destroys the water and nutrient conducting tissue just beneath the bark, causing trees to die. Symptoms include back cracking, woodpecker activity, crown die-back, and ultimately , tree death. Several other borers attach ash. Check symptoms to distinguish between them.

So, as I enjoyed the shade of these fine trees I could not help but think that some day they are likely to be wiped out by a new invasive pest. Forget about eradication. This cat is out of the bag. Individual ash trees will be candidates for insecticide treatment but wholesale protection of woodland trees and most landscape trees is just not feasible. Don't panic now and call the arborist. We'll have more specific instructions when it finally gets here. No sense in treating trees before the bug is here.

For now, enjoy the shade. Think twice before planting ash (we're talking the genus Fraxinus not mountain ash, Sorbus). Be glad that Pennsylvania has only a modest amount of ash in it's forests and landscapes. It may be many years before eastern Pennsylvania deals with this pest. Regulatory agencies are monitoring throughout Pennsylvania to track it's progress. If you happen to see a big purple box hanging in an ash tree, this is one of the monitoring stations.

Click on the Emerald Ash Borer link above to get the full story. You can follow the progress of this insect and read it's history from this site. And watch your ash.