Sunday, July 1, 2012

The "Polka Dot Forest"

Deep into West Virginia, in a quiet valley within a pristine gorge, lies a puzzling sight.  The locals call it the "Polka Dot Forest."   It makes the uninformed wonder a bit, and speaks of a worrisome future to those "in the know."

 What are those "dots" on the Hemlock trees?

In late April, just before Flora-Quest, I had traveled to the New River Gorge in West Virginia with Greg Millerto see what would become my life Swainson's Warbler.  Needless to say the scenery is beyond gorgeous and I would recommend the New River Birding Festival to any of you inclined toward natural things.

 Greg and I enjoyed a day at the Endless Wall Trail at Fern Creek, which I highly recommend for many reasons, including great looks at Swainson's Warblers!  The views of the gorge and the hemlock lined trails create a stunning effect, that you'll not want to miss.

As we walked along, Greg commented to me about the "dots" on the trees.  "What do you suppose they are?"

Realizing the trees were Hemlocks, and fairly up-to-date on the plight of  our natives Hemlocks under siege, I suggested  they might be a scientific study.

 As if a timely apparition, out of the forest (and into our lives) stepped Layne Strickler, a fascinating young lady working for none other than the National Parks Service, treating Hemlock Woolly Adelgid. 

Hemlock Wooley Adelgid infestation on the underside of Hemlock
 Layne told us all about the long term treatment and studies going on at Fern Creek.  She was treating infested hemlocks with the systemic insecticide imidacloprid, and marking the treated trees.  In the past they used a different color spot each year, but the study has gone on long enough, now each tree is tagged and dated each treatment year.  They have also released some biological controls - ie. beetles that feast upon the adelgids.

These studies are very important to those of us in Ohio that understand the significance of our native Hemlock.  It is a keystone species and an integral part of of our ecology at Mohican which we cannot afford to lose.

Since Ohio has recently had it's first occurrences of hemlock woolly adelgid, we are being vigilant against this devastating pest which has forever scarred the face of much of the Great Smokies' forest.
To read more about the work with hemlock woolly adelgid in West Virginia, go here.

 Just past the "polka-dot" part of Fern Creek Forest you'll come to the giant Rhododendron stands.  Beware the Swainson's Warbler in this location... they are mighty plain to look at, but my do they sing sweetly!

Allow a little extra time to admire the Rhododendron as well. This understory specialist relies on the Hemlock and will surely be impacted if we lose the battle with hemlock woolly adelgid.

My money is on Layne.


  1. Thanks for this report! It gives me a little hope for the hemlocks.

  2. Great post! I was just talking to a friend about hemlocks, the wooley adelgid and the beetles that eat them. Now I have a nice link to send along! :)

  3. The good news, they have been doing this study for a good number of years, which means they have kept the hemlocks alive. The bad news- and I hate to think to hard on this- could be the future impact of adding systemic pesticides to our environment. If the tree tissue is filled with chemicals to kill adelgids, what of the other insects? How long does the chemical remain, and will it impact the wood boring beetles who normally inhabit decaying wood? They are an important part of the food chain.

    It is a terrible, complicated issue (one I over-simplified) and one we may not even need to address if the hemlock all die from climate change.

    This is just one more reason to protect the forest ecosystems our forefathers set aside for our enjoyment. They are also our best "hedge" against global warming. Cheryl

    1. There are concerns that we could possibly be saving the hemlocks while killing the forests. Because of this, we know we can't keep this up forever. We have keep the hemlocks alive long enough for another hopeful method of control; Laricobius nigrinus. In previous years, we have released this beetle and other biocontrols without much success in establishing populations. But, we got some really great advice from an entomologist and are going to release more again. Our hopes are high that we will be successful in the next couple years!!

  4. Thank you for the comments. I have questioned in my mind the long-term complications of systemic insecticides, and possible impacts to the food web.

    In fact, is it bad for the beetles to be feeding on "poisoned" adelgids? It is of great interest to us in Ohio.

    Thanks for your comments, and keep us posted. Cheryl