red headed ash borer

Asked July 17, 2014, 3:39 PM EDT

Are the red headed ash borers as problematic as the emeralds?

Black Hawk County Iowa

3 Responses

Thanks for contacting eXtension with this question. The native borers, including redheaded ash borer, ash-lilac borer, ash bark beetles, and flatheaded appletree borer, are usually 'in the background' of severity compared to emerald ash borer. However, this year, we've seen declining ash trees taken out by native borers, especially redheaded ash borer and flatheaded appletree borer. The combination of two or three wet years, followed by several years of drought, and then a very cold winter are taking toll on ash trees (in Iowa).

Unfortunately, once a tree is targeted by the native borers, there's not much one can do to prevent the inevitable (tree death) because the tree is in decline. A borer's job is to recycle the wood in a dying tree to benefit other organisms. These borers, are just doing their job...

I found 1 red headed ash borer in our basement living room. Can I assume that where there's one there are many? I realize that this one just happened to wind up in our house & that they won't eat our house. (unless I was reading incorrect info). But did this one wander away from a nest? Can you tell me what to look for to know if one of our trees has been chosen by the borers?

Thank you for your time. I think the Extension is great. Thanks for doing the job. :-)

Actually, the redheaded ash borer probably came in on firewood or as a rider on someone's clothing (or when a door was left open...). You are correct that it will not eat the wood in your house - it must have 'fresh' declining/dying wood in a standing tree to develop in.

Redheaded ash borers chew perfectly round exit holes in the trunk and branches of the trees they are in. The tree shows various branch death along the stem of the tree. Sometimes, you'll see watersprouts on the affected tree (one of the same symptoms as emerald ash borer), and you'll see adults running up and down the tree trunk.

It is possible the one insect you found flew into the area, as they are fairly strong fliers.

Thanks again for contacting eXtension.