Emerald Ash Borer Update June 15, 2015

RIGHT NOW is the time of year that emerald ash borer (EAB) adults are active. Here are some photos I took last Wednesday in Willow Grove, Bucks County, PA.

EAB 5725

This ash tree had some live branches on it a few weeks ago. Landscape maintenance people have cut and removed them.

Wonder where they disposed of them.

EAB 5727

Tree in same parking lot – adults are now emerging and feeding on leaves

EAB 5735

Adults feeding

EAB 5740

They’re inconspicuous; you might not notice them if you are not looking for them.

Not easy to recognize as a beetle when they’re flying. Not easy to see them when they are feeding on the upper leaf surface, but you can spot their shadows if it’s sunny.

EAB 5743

Adult beetles

EAB 5754

EAB 5763

The emerald ash borer is well established now in this portion of Bucks County. I predict that the spread to surrounding areas is now imminent, as many trees are dying, and inevitably the wood of some of them will be unwittingly relocated.

The emerald ash borer is not the only reason for the decline of the health of ash trees in Southeast Pennsylvania. In some of the neighborhoods where we work, the majority of ashes seem to be dying but there is no sign of EAB.

One factor responsible for this is freeze damage from the warm winter and spring three years ago. Yes, you read that right. Freeze damage. Ash trees normally are one of the last species to get leaves in spring – usually the middle of May. But the consistent warm weather tricked them in to breaking bud over two weeks ahead of schedule. Then we had a surprise late cold snap. Ashes in particular were injured, and many have not recovered from the stress, predisposing them to secondary pests.

Speaking of secondary pests, here are photos of some of the ones I see most commonly. These insect are all native, and are not normally considered a serious threat to ash trees as they don’t usually kill healthy trees.

EAB 7466

galleries of Eastern ash bark beetle in green ash

EAB 7465

EAB 7914Eastern ash bark beetle

EAB 4432banded ash borer emerging

EAB 4452banded ash borer – Neoclytus caprea

EAB 6200collected specimens of EAB, banded ash borer,  Tylonotus bimaculatus (Ash and Privet Borer), another native ash borer.

More on ash and privet borer at July 21, 2009

You can see good photos of more ash pests at Michigan Extension Bulletin E-2939 http://www.emeraldashborer.info/files/e-2939.pdf

Emerald Ash Borer Scouting

The way this client found me is a little bit strange.  He found my website by googling “bacterial leaf scorch” (I have articles posted about my experiences with BLS).  That’s what another “arborist” told him was wrong with his ash tree.  And that the disease would kill the tree, so he should remove it.  Well, ash trees have a few problems around here of late, but bacterial leaf scorch isn’t one of them.  Anyway, the tree didn’t look good and we talked about the true ash ailments – ash anthracnose (which the tree did have) and emerald ash borer (which hasn’t been found close to here yet).  In the end, he agreed we should inspect the tree for EAB, just to be sure.

Today, Ricky and Dave climbed the tree, and the one next to it, and checked it thoroughly.  Good news – negative for EAB.

The ailing ash

The ailing ash

Holes in leaves

Holes in leaves: from the ground you can’t see them in detail, can’t tell if it’s insect feeding damage; close up it doesn’t look like it. More likely caused by damage to buds from our late frost

We look for any clue - here you can see the wood pile contains ash firewood

We look for any clue – here you can see the wood pile contains ash firewood

hackberry emporer butterfly

While we were getting started, this hackberry emperor butterfly came by and took a liking to the minerals on Dave’s hardhat strap.  (Click the image to see a nice big version!)

Dave and Ricky

Dave and Ricky each went up a tree

a good, closeup inspection of the crown

…and did a good, closeup inspection of the crown.

If you have ash trees and are concerned about emerald ash borer now that it has been discovered in Bucks County, right now is the best time to have them checked.  This is the peak time for emergence of the adult insect.

Emerald ash borer update

Have you noticed all those purple sticky traps?

Emerald ash borer sticky trap

Emerald ash borer sticky trap

The PA Department of Agriculture has hung them in ash trees all over eastern PA this summer.  My guess is we’re going to find out about a considerable range increase for this terribly destructive insect.  Already this year, 2 new counties have been added to the list, Huntingdon and Wyoming.  IT IS NOW IN THE EASTERN PART OF PA, having been detected just north of Wilkes-Barre.

Things you need to know: – Adults can fly on their own approx. 1/2 mile.  So the pest isn’t moving very fast on its own.

– It gets help in colonizing territory from people moving infested firewood.

– If emerald ash borer gets close to your area, your landscape trees can be treated by soil injections.  Bigger trees can only, so far, be successfully treated by trunk injection of insecticides.  Treatments need to be done annually to be effective.

– Experts do not suggest treating trees unless an infestation has been detected within 15 miles.  To treat before the threat is there is a waste of money.  And trunk injection is an invasive procedure.  Don’t injure the tree with it until you need to.  And don’t believe anyone who tells you that their trunk injection method causes no injury to the tree.

– If your trees are monitored by a competent arborist, you are not likely to be caught by surprise by emerald ash borer.  If it    shows up, you will have time to control it if you choose to.

NEW information: A new chemical is available that is highly effective and lasts more than one season.  Hopefully it will be  legally registered for emerald ash borer control in Pennsylvania soon.  And hopefully the price will come down (it’s very expensive).

MORE NEW information: A new monitoring tool may soon become available.  Recent research on developing a sex attractant (pheromone) has been promising.  The purple monitoring traps now use two aromatic tree oils as attractant.

Still more new information: Research has also uncovered promising indications of natural biological control of emerald ash borer.
We in southeast PA are lucky to have the benefit of a decade of other’s experience and research before having to face the emerald ash borer.