Beetle Mania

English: Emerald ash borer (Agrilus planipenni...The emerald ash borer has officially arrived in New Hampshire. The larva of this bright metallic green insect has killed millions of ash trees across the country since being spotted in Michigan in 2002. The insect hails from China and it wiped out Michigan ash trees before moving south into other states. Officials knew it was just a matter of time before it would invade New Hampshire.

My son and his family are the owners of a wooded property surrounding their new home in Ohio. Visiting them this summer, he sadly pointed out the ash trees that were either dead or in deep decline from the emerald ash borer. These trees didn’t stand a chance against the invader and last weekend he removed 11 ash trees.

Two years ago at my daughter’s home in Portsmouth NH, I noticed several ash trees with declining canopies on neighboring properties and I told her she should check them for signs of borers. I don’t believe any signs of the borer were evident to her and the trees may have been stressed from other causes, perhaps a previous drought. They were so stressed that in a recent windstorm, one tree fell across the fence into her yard… now a rental property they own.

Ash Tree in Portsmouth NHShe says I must wait for the final verdict from the tree experts to learn what caused the ash to fall. Or if I’m pushy enough, she might let me visit and examine the bark myself.

Sadly, the ash is such a staple of urban life found in landscapes and lining city streets. They are beautiful and majestic trees that replaced the elm trees after Dutch Elm Disease wiped them out. The adult borer eats only the leaves of the ash but the female lays from 60 – 90 eggs in crevices on the bark. The larvae live beneath the bark for about two years before adulthood, becoming pupae in the inner bark the final winter… where a multitude of larvae and pupae interfere with the transport of water and nutrients to the tree’s canopy. In the spring, the insects chew their way out and the cycle repeats.

It’s just beginning in New Hampshire and precautions are being taken. Quarantines on firewood is the first step. Click here to learn about ash trees and exciting new biological steps being taken to find an enemy of the borer. Chemicals have become more effective in treating early infestations in larger trees, applied either by companies or the homeowners.

12-11-2013 Update:  The Emerald Ash Borer has now been detected in the town of North Andover MA. Click on the blog IPM of New Hampshire  for more information.

13 thoughts on “Beetle Mania

    • We certainly have seen some gorgeous Chinese hybrids but these kids of mine are all about nature and the natural order. In order to feed the birds, one must feed the bugs first… and to do that we need good native trees. I just removed all my lilacs (yikes!) that are like plastic plants to insects and birds, according to Doug Tallamy, Chair of Entomology and Wildlife Ecology at the University of Delaware. With our smaller property now, every plant must be carefully considered for impact.


    • The good news about the Ohio property is the trees will be replaced more than one for one. He is not a lawn-dotted-with-trees type of landowner. I’m voting for some native oak trees and perhaps some red maples.


  1. It is unlikely to be Emerald Ash Borer in Portsmouth. So far it has only been found around Concord. People should start to think about their Ash now, and start treating when they are found within about 20 Miles. For protection a soil or trunk application will be adequate.
    Though this is only about 70-80% effective it is good enough until the trees actually get the borer. The soil or trunk application is not detrimental to the tree and is relatively cheap. Once the borer is in the tree only Emamectin Benzoate injected into the tree will give good control. This has been shown to give close to 100% control for two years. It is however expensive and drilling holes in trees always damages them a little, and can be a source for infections. So I always recommend using the bark soil applications as long as possible.


    • Thank you for the information. I did read that they have only been found only in Concord. I’m on the alert since my home is 30 miles away. Good to know that Emamectin Benzoate is the recommended chemical treatment for bark soil application. Folks can learn more about the insect from UNH cooperative extension.


      • Oops Sorry for the confusion. Emamectin Benzoate is only for the injection treatment once the tree is infected. Imidacloprid (merit) is for the soil injection/bark treatment. Emamectin Benzoate is not water soluble enough to be used as soil injection or bark treatment.


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