Thursday, June 29, 2017

Slinging more Silver flies this spring...

We have been at it again this spring with a new predator of hemlock woolly adelgid (HWA).  This is our third consecutive year releasing silver flies on HWA infested hemlocks.

A hemlock branch with both the fall (sistens) and spring (progrediens) generations of HWA.

You see, one of the more annoying characteristics of HWA is that they can produce two generations of offspring in one year.  A fall, sistens generation and the spring, progrediens generation.  The predator beetles that we are so fond of are only active during the fall, which means the adelgids have an entire season to feed and reproduce without the presence of a predator. 

Well, we aim to end that with the introduction of silver flies! 

Our work thus far is with two different Leucopis spp., argenticollis and piniperda.  Both of these species are native to North America.  The silver flies in the West, where hemlock woolly adelgid have been active for millenia, live on hemlocks and feed on HWA.  The silver flies in the East, where HWA has only been resident for the last 50 some odd years, do not live on hemlocks or feed on HWA. So, we are introducing a Western biotype of a native species in order to eat an exotic invasive pest.

I will spare you the lengthy details on permitting and logistics of such an experiment.  Just know that this involves a whole lot of people at several state and federal agencies making sure all that we do is upright and in-line.  We have an amazing cooperator in the Pacific Northwest rearing flies and sending them to us for our experiment.  The big idea in all of this is to establish biological control agents that are able to eat, harass, harangue, or otherwise subjugate HWA, so our hemlock trees can live long happy lives with only minimal damage from the pesky adelgid.

University of Vermont graduate student Kyle Motley readies branches to receive silver flies.

This years experiment is the largest yet with field sites from South Carolina to New York including Great Smoky Mountains National Park in Tennessee.  We are hoping for more positive results!

 A sleeve cage is mounted on an infested hemlock branch. 

We are releasing flies into sleeve cages on infested branches at our field sites, then returning at predetermined intervals to collect the samples in order to find out how well flies are feeding and reproducing. 

"Now here we go dropping science, dropping it all over..."
-Beastie Boys from "The Sounds of Science"

Wednesday, June 21, 2017

Let there be light!

Yep, the "daylighting" of hemlocks has finally begun!

A big thanks to Kenny Frick and Rusty Rhea with Forest Health Protection for bringing the big saw!

Did you see all that light come through the forest canopy?

Based on what we know from anectodal evidence in the field and research done in a nursery setting we can say that hemlocks in full sun tend to be healthier and have lower levels of adelgid infestation.  So, we are bringing that hypothesis to the big woods and trying out a new experiment.  This study has been on paper for quite a while and we have been scouting sites for the better part of a year. 

Basically, we are selecting relatively healthy hemlock trees of a certain size and "releasing" them to a full-sun environment.  Our experiment will test 2 different techniques along with other variables to see if increased exposure to light can help these trees stand up to HWA infestation. 

More details with better quality video and photos are coming!

Wednesday, May 3, 2017

Hope for the Hemlocks: Restoring Balance

A big thanks to Untamed Science for making this short film.  So many people and organizations throughout the country are working to conserve hemlocks.  There is indeed hope!

Tuesday, March 28, 2017

More predators in action!

Just last week we were collecting data for some ongoing research we are doing measuring the impact that predator beetles are having on hemlock woolly adelgid.  We saw evidence of predators on all of our trees, but I was able to capture this satisfying footage of a Laricobius nigrinus larvae feasting on adelgids...


Just how much of an impact are these predators having?  Not sure just yet, but we are part of a regional study hoping to figure that out.  Stay tuned...

Tuesday, February 28, 2017

Visiting The Smoky Mountains...

At the beginning of the month, Bud and I visited Great Smoky Mountains National Park to talk about a research project we would like to do there and look at some potential sites.  Driving through Gatlinburg, we were astounded at the damage caused by the wildfires this past fall on the park lands, but even more so the damage in downtown Gatlinburg itself! 


Like so many others, I followed the news stories as the fires were ongoing, but it is very different to visit.  People all around town are actively picking up the pieces and rebuilding.  These were devastating fires, a tragic reminder that we must be vigilant stewards of the environment we live in and ever aware of local climate conditions.

 Only the foundation and chimney remain of a house near downtown Gatlinburg.

  Fire damage in some of the hemlock forest on park land.

Our trip was productive and despite the damage caused by wildfires, there are still good sites with surviving hemlock where we can do the proposed research. We also got to see some of the largest living hemlock trees that I have personally had the pleasure of seeing.  These beauties were over 100 feet tall!  The foresters at GSMNP have treated over 250,000 hemlock trees!  Obviously, they are working hard to preserve this vital tree species. 

A mature hemlock stand at GSMNP.

On the way back to Asheville we had this view of the park.  Yes folks, despite the warm temperatures, it is still winter.  The lighter color along the mountaintops is indeed ice.

 A view of GSMNP from the Foothills Parkway.

Monday, February 6, 2017

Coming soon ...

I recently had the distinct pleasure of introducing the Untamed Science film crew to some of our hemlock sites and research.  You may remember a fire video I shared on a previous post.  That was them.  Most recently, Untamed Science did this excellent short on the USFS Hydrological Lab at Coweeta.  Now, Rob and Trenton are making a film about invasive pests of southern forests and will be relating the loathsome tale of how hemlock woolly adelgid is reshaping our forests.

 Trenton mounting a Gopro camera to one of the vehicles.

Our first stop was to meet Dr. Pat Parkman who runs the beneficial insects laboratory at UT-Knoxville.  I showed the guys some hemlock habitat on our way through the mountains to TN, then we got the full tour of his facility including a primer on beetle life cycles.

Dr. Parkman sketches out the Laricobius life cycle for Rob.

We only had 2 full days with the crew and oh so much to show and tell.  Our cooperators from CAMCORE, Dr. Robert Jetton and Andy Whittier, met up with us at Dupont S.F. where we talked about cone collection and seed conservation.  I am especially hoping the tree climbing shots make it into the film.  You will also see gripping interviews with Forest Service scientists including our very own Dr. Bud Mayfield, who will educate us on hemlock conservation efforts.

Trust me you are not going to want to miss this...


Thursday, November 17, 2016

Fall Fires of 2016

Since September, we have been watching the woods gradually dry up.  There has been an audible change trekking to and from our sites throughout the mountains this fall.  The gentle shuffling sounds of walking on leaves and sticks has become a loud crunch, crunch and thud, thud on an increasingly dry and dusty forest floor.  When we started seeing this happen, we knew the drought was on.

The curling leaves of a Rhodendron maximum shrub in TN.

When you start seeing the leaves curl up on these big Rhododendron bushes you know they are conserving their resources and stressing out a little.  We have research sites stretching from the piedmont of South Carolina to the mountains of North Georgia and Western North Carolina all the way over to the Cumberland Plateau of Tennessee.  We have been visiting these sites all summer and fall watching drought take hold and the subsequent fires start.  Here is a video from a site in TN.


I realize you may not be impressed by the quality of that video, but please notice 2 things.  1) The loud crunching of leaves as I walk.  2) The complete lack of water coming over that large cliff.  This is what is usually going on at Upper Piney Falls.

Photo of Piney Falls borrowed from American Travel Journal Blog.

Thankfully, none of our research sites are in danger of burning...yet.

And here is the problem.

We are in a drought y'all! These dry forest conditions are perfect for ignition of wildfires and boy are we having our share of wildfires. 

An aerial image of fires in the Southern Appalachians compliments of NASA's Aqua Satellite.

Remember that in our Southeastern forests there are beneficial, non-threatening fires.  You can learn about those here.   The wildfires we are experiencing now are not of that amiable variety.  So in these treacherous conditions please take Smokey's advice: