Biocontrol Update

On January 10, HRI staff virtually attended the “HWA Initiative: Biological Control Working Group Meeting.” This annual meeting is put on by the USDA Forest Service at the start of the USDA Interagency Research Forum on Invasive Species. During the meeting, predator-rearing labs shared updates, researchers presented new findings, and land managers discussed the establishment of predator populations. 

That’s why for this year’s newsletter, we wanted to highlight recent biological control efforts. For anyone unfamiliar, biocontrol is defined as using beneficial insects or pathogens to control unwanted species. In the case of hemlock woolly adelgid, researchers have studied many potential species over the years, with recent efforts focused on Laricobius beetles and silver flies (Leucotaraxis).

eDNA
One realm of research that we are excited to follow is eDNA. Environmental DNA, or eDNA, is a relatively new technique in invasive species management. This method involves collecting and analyzing small samples of water, soil, or other environmental materials for the DNA of the target species.

At the meeting, Tonya Bittner presented the New York State Hemlock Initiative’s research on eDNA. This lab’s 2022 research paper focused on detecting hemlock woolly adelgid, Laricobius beetles, and Leucotaraxis silver flies. Using careful research methods, the researchers were able to collect the eDNA of these species in a positive correlation with the observed density. 

So, what does that mean for us? 

Continued development of eDNA methods could mean earlier detection and faster response to HWA infestation. This is because we currently detect HWA by visually inspecting trees for signs of infestation, whereas eDNA methods can detect the presence of HWA much earlier and with greater accuracy. It can also be used to detect biocontrol species, which will be especially useful when evaluating the establishment of Leucotaraxis because the flies are inconspicuous and difficult to detect in the field. 

Leucotaraxis silver flies
You might be wondering: who is this new kid on the biocontrol block? HRI has been talking about Laricobius beetles for years, but Leucotaraxis is an exciting newer development. Just as Laricobius nigrinus is a native HWA predator in western North America, so are the two species of Leucotaraxis, Le. argenticollis and Le. piniperda, currently under investigation. 

Leucotaraxis silver flies. are a type of predatory fly that feeds on the eggs of HWA during their larval life stage. They complement Laricobius beetles, as they feed on HWA over a longer portion of the adelgid’s life cycle than Laricobius. The establishment of these two silver fly species would likely result in increased HWA control.

It is especially exciting that continued understanding of Leucotaraxis is happening concurrently with the development of eDNA. When researchers release these insects into the field, they need to know when and where the species become established. Leucotaraxis has proved more difficult to recover than Laricobius, so eDNA is a promising new tool for studying release timing and procedures. 

For more information about silver fly or eDNA research, check out the New York State Hemlock Initiative website by clicking here. 

HRI Biocontrol History
Since our inception, HRI has been deeply involved with Laricobius establishment and monitoring efforts in North Carolina. In 2014 and 2015, HRI supported the Blue Ridge Resource and Conservation Development Council to hold workshops for conservation partners on how to select sites and establish Laricobius nigrinus insectaries. Over the following three years, Buncombe County supported HRI to advance the effort to establish L. nigrinus in hemlock stands throughout the county with the knowledge that the beetles released in the county would eventually disperse to other parts of WNC. 

Both of these projects led to additional interest by town and public land natural resource managers, such as the Town of Montreat’s decision to incorporate L. nigrinus beetles into an IPM strategy to manage their many hemlocks. HRI has been conducting strategic releases and monitoring both release sites and non-release sites for signs of Laricobius spp. establishment throughout the state’s hemlock populations ever since. 

When the NCDA&CS decided to start rearing a colony of Laricobius beetles in their Beneficial Insect Lab in Cary, NC, HRI was in a perfect position to supply them with beetles and to further support the lab by collecting infested branches to serve as a food for the hungry little helpers as they grow. HRI continues to work with multiple partners to integrate biological control into the larger strategic effort to manage and control HWA across the state. If you are curious whether these tiny little predators are feasting on HWA on your trees, the next few months are the perfect time to look! See the how-to instructions on our website and please let us know what you find!

Volunteer Spotlight: In Memory of Chuck Hackford (1947 – 2022)

The Hemlock Restoration Initiative could not do what we do without the help of our hard-working volunteers. Each newsletter we like to highlight the contributions of one especially dedicated volunteer. In this issue we would like to recognize one of our earliest volunteers, Chuck Hackford, who, we were grieved to learn, passed away in November 2022. Chuck’s wife Ann graciously sat down with us to share her memories and stories about Chuck for this article.

Chuck Hackford recognized there was a problem with his hemlock trees right away. Four mature hemlocks lined the driveway up to the house near Brevard that he and his wife, Ann, moved into after coming to Western North Carolina from Oregon in 2016. Chuck, being attuned to nature as a lifelong hunter, hiker, and lover of the Earth, could tell something was wrong with the hemlocks. “They don’t look well,” he said to Ann. As he explored their new six-acre property adjacent to DuPont State Recreational Forest, he found more hemlocks in dire condition.

With a little help from his sister in Georgia, who had been treating hemlocks on her property, Chuck discovered that his trees were suffering from HWA. This led him to reach out to HRI in the fall of 2016 for information on how he could help his hemlocks. We invited Chuck and Ann to come volunteer with us to learn how to treat their hemlocks, and shortly thereafter they joined us for the first of several volunteer days at DuPont, becoming part of the early cadre of HRI volunteers. 

“When I am here, I understand who I am.  I understand why I am here.  It is simply to find peace with myself.  With this knowledge, the world isn’t so big and the trivia of everyday life is meaningless.”

Chuck Hackford

Chuck was especially interested in helping the hemlocks at DuPont, which was effectively a very large extension of his backyard. His love of DuPont just continued to grow the more time he spent wandering the hills, enjoying views, sitting by streams and waterfalls. “It was his chapel,” said Ann, “a place he went to nourish his spirit. He lived as a part of the Earth, as one tiny cell, always conscious of his role.”

Chuck’s connection to the Earth and love of the outdoors began at an early age. His grandfather taught him to hunt grouse and pheasant in the woods of western New York. As an adult, he loved to hunt deer. Even when not hunting, we would always be looking for animal signs, signs of bears or deer, seeing with a tracker’s eye. “He was a backwoods guy. He loved going off trail, meandering,” Ann recalled. “He would find a big rock with a vista in order to get a new perspective on the land.” 

“The joy of life is new experiences and being one with nature! As I travel into the wilderness, I travel into myself.”

Chuck Hackford

With HRI, Chuck helped treat hemlocks in several parts of DuPont, including Sandy Trail, Grassy Creek Trail, Twixt Trail, the Wintergreen Falls area, and along Cascade Lake Road. Whether it was a large, sick hemlock or a young seedling, Chuck, wanted to help save them all. Today those old, grand trees are starting to recover, and those seedlings are several feet taller on their way to becoming the next generation of giants. Ann remembers that he would go visit the trees he helped treat from time to time, checking on their progress. Over the years, Chuck and Ann also treated around 50 hemlocks on their own property. 

While volunteer days with HRI have always been very fulfilling for Ann, by the end of the day she would be exhausted from scrambling up and down hillsides or crawling through the brush. “But for Chuck, it was invigorating,” she said. “He always wanted to explore the hard to reach areas, find the hardest trails.” 

His love of the Earth is what motivated Chuck to give back. Besides volunteering with HRI and caring for his own hemlocks, he gave his time as a member of the Friends of DuPont Forest trail crew and litter pickup volunteers. From 2019 to 2021, Chuck and Ann took over as the organizers of the litter pickup and renamed it Trash Bash. “He was happiest outside, giving back as much as he received from Mother Nature,” Ann said, “and he loved being able to actively participate in caring for the trees and keeping the forest clean.”

Ann recalls many early morning hikes with Chuck, always on weekdays to avoid the crowds. “Walking in the fresh snow, with only our tracks or maybe turkey tracks, it’s such a blessing,” said Ann. She still pictures Chuck walking in front of her when she’s out in the woods. As for those four big hemlocks by the driveway, to Ann they are now a lovely physical reminder of Chuck and all he cared about.

(I desire) “to understand and be a part of the simple beauty of nature.  There is no good or bad here, just natural law.  No judgments.  We come as we are, do our best, take joy in simply being a part of the web of life.  Caring about all things around us, equal in the struggles to survive and understanding we are all, every living thing, together.  If you must find yourself, look to the natural world.”

Chuck Hackford