The hemlock woolly adelgid has ravaged New York state since the 1980s, most likely after
arriving on infested nursery stock. The juvenile hemlock woolly adelgids insert their
mouthparts into a tree’s stored branches, disrupting the flow of nutrients and severely
damaging the canopy of the host tree. The invasive insects aggressively target eastern
hemlock trees and have significantly diminished hemlock populations in the northeast. It is
now estimated that, “over the past ten years, [hemlock woolly adelgids have] killed tens of
thousands of hemlocks” [1]. Hemlocks are efficient at storing carbon dioxide and,
according to a 2002 study, hemlocks were found to “sequester approximately 12 metric
tons of carbon dioxide per two and a half acres” [2]. As hemlocks are highly efficient at
storing carbon dioxide, researchers have begun developing and testing novel treatments
intended to increase hemlock resistance to the woolly adelgids.
This summer I had the privilege of interning at the Mianus River Gorge Preserve, a
maintained wildlife preserve located in Bedford, NY seeking to preserve their land through
scientific research and public education. The Mianus River Gorge encompasses “a
magnificent cathedral of 350-year-old hemlocks that stand more than 100 feet tall” [3] and
has worked to survey their hemlock trees with research support specialist Nicholas
Dietschler from the University of Cornell. This past summer Mr. Dietschler was testing
hemlock trees for the presence of a treatment he had administered three years prior.
Alongside fellow interns, I assisted Mr. Dietschler in sampling the uppermost branches of
the hemlock trees, which is necessary to determine if the hemlock trees have retained the
treatment for three years. This involved a practice I initially found sustainably questionable:
Mr. Dietscher proposed harvesting the uppermost branches by shooting them down with a
twelve-gauge shotgun.
While I understood the importance of accessing the uppermost branches, I struggled to
understand blasting the branches off the same threatened tree that we sought to protect.
The use of a shotgun involved the risk of introducing shotgun shells, wadding, and shot into
the carefully maintained preserve. At a previous internship, I had been told about a less
aggressive means of sampling hemlock branches involving a homemade tennis-ball-
launcher, intended to knock branches down with a tennis ball projectile. When I asked Mr.
Dietschler why he didn’t prefer the tennis ball method, he explained that his team would
often lose many tennis balls in a day of sampling, and that they found it time-consuming to
knock down enough branches. After a day in the field shooting down branches, I can attest
to the necessity of a time-efficient means of collecting branches and can further speak to
how disruptive the shooting is to the environment.
The interns were enticed by the proposal of using shotguns in our field research, including
Emily Valenti, a senior undergraduate student at SUNY’s College of Environmental Science
and Forestry. When I asked Emily to recall her initial reaction to the research, she
expressed that “initially hearing that we were shooting at trees was a little funny”. While
accompanying Mr. Dietschler into the field, Emily recalled that “sometime before shooting
we consulted someone who had his dog nearby, I know he had expressed frustration in the
past regarding the research”. There is no rifle hunting permitted in Westchester County, so
it’s no surprise that many would view the practice as invasive and disruptive to the
protected wilderness area.
Last summer was Mr. Dietschler’s third year of sampling with his team at the Mianus River
Gorge. This gave me the opportunity to observe sites that had experienced the effects of
both the hemlock woolly adelgid and the shooting of branches from years prior. The
insect’s rapid deterioration of hemlock branches and needles was present at every site and
was far more significant than the absence of previously sampled branches. We try to avoid
leaving spent shells behind by cleaning up after each shot, however, at two sites I found
ejected shells and wadding on the ground left from prior shooting. Aside from the loud
noise from the shotgun, this was the only evidence that I could find that indicated the
sampling had taken place.
I spoke with intern Landon Highbloom, an undergraduate environmental studies major at
Washington University, about his opinion on the public reaction to the tree sampling.
Landon explained that “there is a fear component when it comes to using guns, even if it’s
for ecological research, but the ease with which we sampled the branches showed how
useful the shotguns were”. Coming from a background in science communication, Landon
noted that while this public reaction is understandable, but feels that “from a sustainable
aspect, the positive impacts of doing this type of research far outweigh the potential risk of
minor litter or debris”.
As hemlock woolly adelgid populations continue to expand and wipe out native eastern
hemlock trees, the need to develop an effective long-lasting treatment to increase hemlock
resistance continues to grow. After experiencing a controversial means of sampling
hemlock branches, I believe that the shooting of hemlock trees in order to collect samples
is a viable practice. Furthermore, I feel that having witnessed the rapid tree death caused
by hemlock woolly adelgids, the use of an unconventional sampling method is warranted
to mitigate the ecological disaster.
The northeast currently faces many rapidly developing ecological threats including
overpopulations of deer, ticks, and invasive plants. After witnessing the true implications of
the shotgun research alongside Mr. Dietschler, I feel it will become increasingly necessary
for researchers to employ unorthodox practices to discover new, effective techniques for
combatting ecological threats.
[1] Hemlock Woolly Adelgid - The Arbor Day Foundation.
https://www.arborday.org/trees/health/pests/hemlock-woolly-adelgid.cfm. Accessed 15
Oct. 2024.
[2] Teirstein, Zoya. “The Northeast’s Hemlock Trees Face Extinction. A Tiny Fly Could Save
Them.” Grist, 4 Aug. 2021, https://grist.org/science/the-northeasts-hemlock-trees-face-
extinction-a-tiny-fly-could-save-them/.
[3] “Visit New York’s Mianus River Gorge Preserve.” The Nature Conservancy,
https://www.nature.org/en-us/get-involved/how-to-help/places-we-protect/eastern-
mianus-river-gorge-preserve/. Accessed 28 Oct. 2024.