Tag Archives: hemlock woolly adelgid

Cool Science, Flora & Fauna, Research

Big Hopes for Little “Army” in Parks’ Fight against Hemlock Invaders

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As the third most common tree in New York, hemlocks fill our forests and are found in many New York State Parks. Located along hiking trails, streams, gorges, campsites, and lake shores, the evergreens can live to be hundreds of years old, providing vital ecosystem services and supporting unique habitats.

In addition to providing homes and food for many forest creatures, hemlocks also keep fresh water resources cool and clean by moderating water temperature and acting as a natural filtration system along streams. Since hemlocks are such a critical component of eastern forests, they are known as a “foundation species.”

Hemlocks in New York have been under attack by an invasive forest insect pest that originated from southern Japan, the hemlock woolly adelgid (HWA), which after being found in Virginia in the 1950s has spread to kill untold millions of hemlocks from Georgia to Maine.

Hemlock Woolly Adelgid infestation in the Eastern U.S. (U.S. Forest Service)

Adelgids are tiny insects that insert piercing-sucking mouthparts into hemlock twigs, causing damage to woody tissue that inhibits water and nutrients from reaching emerging hemlock buds. This limits the growth of new twigs and eventually kills the tree.

First detected in New York in the 1980s, the insects have spread through the Hudson Valley, Catskills, Southern Tier and Finger Lakes regions. Infested hemlocks can be found at state parks including Harriman, Minnewaska, Taughannock Falls, Watkins Glen, Letchworth, and Allegany.

At about 6/100ths of an inch long, the flightless adelgids are hard to spot, but in the winter through early summer leave distinctive white “woolly” egg masses on hemlock twigs. In an infestation, developing buds are killed first, then in a few years, the weakened tree loses its needles and dies.

Left, a dead hemlock after being killed by HWA. Right, a healthy tree.
A map of New York State towns and counties where HWA had been found in the Hudson Valley, Capital Region, and Southern Tier by 2017. The HWA has yet to move into the Adirondacks or the Tug Hill Plateau. (State Department of Environmental Conservation)

The threat posed by HWA is dire, especially since the state’s ecosystems lack natural controls _ known as biocontrols _ such as predators or tree resistance that could fend off some infestations and avert widespread hemlock destruction.

Currently, insecticide treatments are our only sure option for saving trees, but trees must be treated on an individual basis, so it can be costly or impractical to treat large swaths of hemlocks. In parks with thousands of trees and important or rare ecosystems to protect, biocontrol is the only solution to counter a pest like HWA.

But biocontrol against the invading adelgid may be on the way. It is the form of a small dark beetle and a small silvery fly, nicknamed “Little Lari” (Laricobius nigrinus) and “Little Leuc” (Leucopis spp.), respectively, by researchers at the New York State Hemlock Initiative at Cornell University.

Led by forest entomologist Mark Whitmore, the program operates a biocontrol lab researching the introduction of HWA predators throughout New York, hoping to protect hemlock trees by slowing the spread of adelgids into new areas.

The NYSHI collects these predators in the Pacific Northwest where HWA is native and has many predators controlling population growth so the hemlocks are not damaged. The collected beetles and flies are shipped to the quarantine facility at Cornell  to be certain none of the western adelgids are accidentally introduced into New York with the predators.

Knowing where to release these “good bugs” can be a challenge, but we are helped in this by State Parks staff, who provide critical data from ground surveys to find emerging infestations, assess potential biocontrol sites, and monitor for whether the biocontrol insects are thriving and growing in their new homes.

Read this post in the State Parks blog by Abigail Pierson, state Parks Forest Health Specialist, to learn how crews search for and document the presence of HWA.

Since 2009, the Cornell initiative has released more than 4,500 Laricobius beetles in State Parks including Harriman in Rockland County, Letchworth in Wyoming County, Mine Kill in Schoharie County, and Taughannock Falls, Buttermilk Falls, and Robert H. Treman in Tompkins County. Additionally, parks staff at Minnewaska State Park Preserve in Ulster County helped survey for Laricobius beetle establishment, and mapped hemlocks to help identify hemlocks stands and prioritize HWA surveys in the park. 

Since 2015, when Leucopis silver fly releases began, researchers have released more than 3,300 flies at several state park sites including Taughannock Falls and Buttermilk Falls state parks in Tompkins County.

“Little Lari” (Laricobius nigrinus) (New York State Hemlock Initiative)
“Little Leuc” (Leucopis spp.) (New York State Hemlock Initiative)

While there has been no evidence of the biocontrol bugs suppressing HWA populations on a large scale, it takes time for predator populations to build. There has been recovery of Laricobius beetles at some sites, indicating establishment. By continuing to release more “Little Laris” and “Little Leucs” to bolster those established populations, we will be able to build on that initial success.

The list of parks that have reported HWA infestations is growing, especially in the Capital Region. Thacher State Park in the Capital Region reported adelgid infestations in 2017 and while insecticide treatments reduced the local problem, the insects continue to threaten the Adirondacks, which so far remains uninfested.

In State Parks, preventing dead trees from injuring park visitors or damaging park infrastructure including campsites and trails is crucial. Additionally, preventing the loss of a critical foundation tree species in forest habitats is another major priority.

Park visitors can play an active role in slowing the spread of the adelgid in New York by keeping an eye on hemlocks. Reporting any infestations that you find provides researchers and land managers with invaluable data for improving our management efforts.

How You Can Help

If you believe you have found HWA:

  • Take pictures of the infestation signs (include something for scale such as a coin or ruler).
  • Note the location (intersecting roads, landmarks or GPS coordinates).
  • Fill out the hemlock woolly adelgid survey form.
  • Email report and photos to Department of Environmental Conservation Forest Health foresthealth@dec.ny.gov or call the Forest Health Information Line at 1-866-640-0652.
  • Contact your local Partnership for Regional Invasive Species Management (PRISM) by visiting http://www.nyis.info/.
  • Report the infestation at iMapInvasives.
  • Slow the spread of HWA in our forests by cleaning equipment or gear after it has been near an infestation, and by leaving infested material where it was found.

The New York State Hemlock Initiative has produced a variety of educational videos on the threat posed to hemlocks by the HWA.

Cover Photo: A hemlock branch showing the woolly white egg masses of Hemlock Woolly Adelgid. (New York State Department of Environmental Conservation)

Post by Charlotte Malmborg, Education and Outreach Technician, New York State Hemlock Initiative, Cornell University Dept. of Natural Resources

Cool Science, Flora & Fauna, Park Personnel, Stewardship

A View from the Treetops: life as a forest health specialist

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My name is Abigail Pierson and I am a Forest Health Specialist for NYS Parks. The scope of my work covers almost all the state parks in the western half of New York state, making each week always something new and exciting.

My week begins with the usual desk work of contacting park managers and anything else to ensure a smooth work week. However, by 10 a.m. my coworker and I are hopping in the work van and traveling to a state park. Once we’ve arrived, my partner and I begin setting up our tents and going over our schedule for the week. When the work day comes to end, it’s time for arguably the most intricate task of the day, dinner.

Abby and her current NYS Parks staffer and climbing partner, James Boyd.

Our meals are cooked on a two-burner camp stove, so chaos usually ensues when we are both starving and trying to prepare full course meals. Trying to make a full meal on one burner each serves as a microcosm of the balance of respect, teamwork, trust, and cooperation needed for the success of our team.  We spend every morning, afternoon, and night together for five days of the week. This job requires a lot of trust. We are climbing tall trees for research purposes, so our safety depends on each other. It is amazing to have a job/life experience like this where your co-worker becomes such an integral part of your life.

It’s always interesting climbing out of our dew-covered tents each morning; seeing everything in nature slowly coming to life all around us. Our days move by very fast. I eat a quick breakfast, after which I grab my climbing gear and data collection tools and begin the hike into a hemlock stand.

We are monitoring for hemlock wooly adelgid (HWA) an invasive insect species native to Japan that can kill entire hemlock stands in 4 to 10 years. Our hikes to these hemlock stands can range from a half mile to three miles, and this is where the real fun begins. We put on our helmets and safety glasses and begin sending our rope up and over one of the branches in the middle canopy of the tree. Once we have our single rope set up and secured on the tree, one of us straps on our climbing harness and begins the ascent, which can be a hundred feet or more up into the air.

Abby gears up with NYS Parks staffer Jake Sidey during a 2016 climb.
Abby having fun a phone app with NYS Parks staffer and 2017/18 climbing partner Ben Jablonski.

A beautiful thing about our climbing setup is we cause no damage to the tree. Our goal is to save these majestic giants, not injure them. Once I reach the top section of the rope, I attach myself directly to the tree using a flip line. A flip line is a short adjustable section of rope that goes around the trunk of the tree and attaches to both sides of my harness.

It’s a good thing I’m a tree hugger because I must hug the tree as I use flip lines to ascend to the top canopy of the tree. It is a very intense experience being on flip lines because it is up to myself and this tree to keep me safe. In many ways, we are trusting the trees with our lives just as much as the trees are trusting us with theirs.

Climbing to the very top canopy of a tree that usually towers over the rest of the forest canopy is an indescribable experience. It feels as if, for a moment, you are larger than the forest itself. After all that hard work of getting to the top canopy I always take a moment to take in the beauty of nature that is surrounding me.

The View from the Top.

Once I’ve taken in the view it is right back to work. I take a small sample of a branch from the top canopy and put it into a labeled Baggie. As I descend back down the tree, I take samples from the middle and lower canopies. These samples allow us to identify if the tree is healthy or its level of infestation by HWA, a tiny aphid-like insect that gradually kills hemlocks by feeding on the juices in their needles.

The information that we gather helps show how widespread HWA is in the state and which hemlocks might still have the potential to be saved.

Here, and below, A close up of the telltale fluffy white insect egg masses that indicate HWA infestation.

If left unchecked, HWA could wipe out the majority of eastern hemlocks in New York, a species that is the third most common tree in the state. Hence the importance of slowing or even stopping its spread as quickly as possible. Widespread hemlock mortality would have a lasting impact on ecosystems, streams, flora and fauna, and even the look of the landscape.

Hemlock mortality in parks especially is a scary thing for me to imagine as patrons would no longer be able to enjoy the parks the same way that they can now. Some of our most well-known parks, including Letchworth, Allegany, Watkins Glen, and others like Stonybrook and Thacher, feature hemlocks along most major trails and vista points. Campgrounds and picnic areas of many parks enjoy cooling shade courtesy of hemlocks. If those hemlock stands were to die back the park would look barren, be unsafe due to erosion and dead limbs, and the internal ecosystems would be negatively impacted as well.

On the left, hemlock trees killed by HWA. On the right, a healthy, uninfested hemlock.

Click here for a map showing how HWA has spread in New York State.

What can you do to help? According to the state Department of Environmental Conservation, if you believe you have found HWA:

  • Take pictures of the infestation signs (include something for scale such as a coin or ruler).
  • Note the location (intersecting roads, landmarks or GPS coordinates).
  • Fill out the hemlock woolly adelgid survey form.
  • Email report and photos to DEC Forest Health foresthealth@dec.ny.gov or call the Forest Health Information Line at 1-866-640-0652.
  • Contact your local Partnership for Regional Invasive Species Management (PRISM) by visiting http://www.nyis.info/.
  • Report the infestation at iMapInvasives.
  • Slow the spread of HWA in our forests by cleaning equipment or gear after it has been near an infestation, and by leaving infested material where it was found.

Overall, tree climbing is a phenomenal experience that allows us to experience the sheer beauty of the hemlock tree and surrounding forest, while also allowing us make the in-depth assessment needed to ensure that the natural beauty is preserved.

Helping to save the amazing environment we live in, educating the public on invasive species, and being up close and personal with nature every day is an amazing gift. This job allows me to fulfill all my strongest passions simultaneously and I could not be luckier to have this opportunity.

Born to climb: A young Abby is geared up for tree climbing up by her father, Dr. Timothy G. Pierson, during Penn State Agricultural Progress Days. Abby later got her bachelor’s degree in environmental science/biology from Penn State, where her father worked as a forester.

Post by Abigail Pierson, Forest Health Specialist

Flora & Fauna

Know The Needles

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This time of year, much of New York’s landscape is dappled with bare-branched deciduous trees and dark, evergreen conifers. These cone-bearing conifer trees are adapted to survive harsh, cold weather, from the microscopic structure of the leaf to the overall shape of the entire tree. Despite the needle-like shape, conifer leaves serve much the same function as the flat, broad leaves of a sugar maple or oak tree. Most conifers keep their needles year-round. Do you know which New York native conifer drops its needles every fall? It is the tamarack (Larix laricina), a member of the larches, shown below.

ChangingTamaracks
Steven Katovich, USDA Forest Service, Bugwood.org

TamarackNeedles
Rob Routledge, Sault College, Bugwood.org

On the left, these tamaracks are changing color. Every autumn the needles turn bright yellow and will fall off the tree by winter, so they are not considered an “evergreen.” On the right, a closer view of tamarack needles, which grow from a woody spur in clusters of ten to twenty. The needles are approximately ¾” to 1 ¼” inches long.

When talking about evergreens, pines may first come to mind, but conifers also include firs, spruces, hemlocks, and others. But how do we tell which is which? Here are a few quick tips to help narrow down the tree group simply by looking at the needles.

Pines

First, let’s look at pines. Pine trees have needles in bundles on the stem. The number per bundle depends on the species, but if you find bundles of five needles or less, you’ve likely discovered a pine. There are six native species of pine in New York, but two you may be most likely to encounter are white pine (Pinus strobus) and red pine (Pinus resinosa).

WhitePineTree
Steven Katovich, USDA Forest Service, Bugwood.org

WhitePineTreeRobert Vidéki, Doronicum Kft., Bugwood.org
Robert Vidéki, Doronicum Kft., Bugwood.org

WhitePineNeedles2
Bill Cook, Michigan State University, Bugwood.org

The eastern white pine (left) and its bundled needles (middle and right). This species of pine has five needles per bundle (and as a memory trick, there are five letters in the word “white”). The needles are soft and flexible, measuring about 2 to 4 inches long.

Spruces

Spruce trees have needles that are individually attached to the branch with small woody pegs. A key characteristic for spruce needles is that they are square and can roll easily between your fingers. They are usually sharply pointed. Also, if any needles are shed the woody pegs make the branch feel rough, unlike the smooth branches of firs. There are three native spruces in New York: the white spruce (Picea glauca), the black spruce (Picea mariana), and the red spruce (Picea rubens).

WhiteSpruceTree
Bill Cook, Michigan State University, Bugwood.org

WhiteSpruceNeedles
Joseph OBrien, USDA Forest Service, Bugwood.org

The white spruce (left) and its needles (right), notice the woody pegs that attach the needle to the branch. Needles are stiff and measure about ½” to ¾” inches long. This species is sometimes called skunk spruce or cat spruce due to the strong odor from broken needles.

Firs

Fir needles are also individually attached, but unlike spruces, they are attached by what resembles a suction cup (look for a circular base). They are typically soft and flat with rounded needle tips. There are two whitish lines on the bottom of the needle. Another distinguishing characteristic of firs is that their cones stand upright on the branches, rather than droop down. The only native fir that can be found in New York is the balsam fir (Abies balsamea).

BalsamFirTree
Steven Katovich, USDA Forest Service, Bugwood.org

BalsamFirNeedles
Joseph OBrien, USDA Forest Service, Bugwood.org

A stand of balsam fir (left) and its needles (right). Balsam fir needles are dark green and measure around ¾” to 1 ½” in length. The tips of the needles can be blunt, rounded, or notched.

Hemlocks

Hemlocks have individually attached needles that are flat. Unlike firs, each hemlock needle has a small stem attached to a woody peg. In New York there is only one native hemlock species, the eastern hemlock (Tsuga canadensis). While you’re out testing your needle identification skills, keep an eye out for the invasive pest hemlock woolly adelgid, which creates white woolly masses at the base of hemlock needles. This insect causes tree health to decline and can lead to the death of the hemlock in as little as four years.

EasternHemlockTree
David Lee, Bugwood.org

EasternHemlockNeedles
Rob Routledge, Sault College, Bugwood.org

A young eastern hemlock stand (left) and its needles with stems (right). Needles are usually a shiny green. On the underside of each needle, you can see two characteristic white lines (shown in the picture). The needles are typically one inch or less in length.

So there you have it! Next time you’re out scratching your head, wondering if you’ve encountered a white spruce or a white pine, ask yourself these simple questions:

  • Are the needles in bundles or individually attached?
  • Does the needle roll easily between your fingers or is it flat?
  • Are the needles attached to a stem, woody peg, or a “suction cup” structure?

Just by taking a quick look (and maybe pluck) at the needles, it is often possible to categorize the conifer into pine, spruce, fir, or hemlock. If you come across a conifer that doesn’t fit into these categories, try looking at cedars or junipers too. And the best part of studying conifers is that you can look at needles all year long! Unless it’s a tamarack, of course.

If you’d like to learn more about some key conifers, check out this blog post to learn about identifying specific species you may encounter in State Parks!

Post by Kelsey Ruffino, State Parks

Resources:

Cover Photo – Eastern Hemlock: CC BY-SA 3.0, https://commons.wikimedia.org/w/index.php?curid=298754

Park Projects, Park Volunteers

Keep An Eye Out For HWA

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The winter is a great time to visit State Parks in New York. Even in these colder months, opportunities for recreation are abundant and each year State Parks welcomes cross-country skiers, snowshoers, and hikers, who enthusiastically explore the many miles of trail that are open and maintained for winter activities.

Many recreationists are as eager to hit the trails in the winter as in the warmer months, but most are likely not aware that by enjoying their favorite winter past-time, they are also able to aid State Parks Biologists and staff in detecting an insidious invasive pest.

The Hemlock Woolly Adelgid (HWA), is a non-native, invasive aphid-like insect that infests Eastern Hemlocks throughout New York State, and across most of the eastern US. The insect attacks the tree by attaching to the underside of the branch at the base of the needles, and feeding on the sap. The tree will respond by shutting down resources to the damaged areas. Eventually, as the infestation spreads, the tree dies – the insects having essentially sucked the life out of it.

Currently, work is being done throughout NY State to try to slow the spread of this pest. However, in order to combat HWA, researchers first need to know where it has (and hasn’t) been found. This creates an opportunity for concerned and conservation-minded citizens to provide a great service to the parks they love, and to help to protect the natural beauty that they cherish.

Hemlocks, one of many coniferous (cone-bearing) species throughout New York State, can best be identified by their needles, which are flat, generally a little more than an inch long, and have two white lines running parallel on the underside. The winter months are the best time of year to check these trees for HWA. The insects, which lay eggs in the fall, coat the egg sacks with a white, woolly protective layer, which allows the developing young to survive the winter. This white “wool” also makes the egg sacks very visible throughout the winter months (mainly December-March), and allows observers, with little to no formal training, to detect the presence of HWA in hemlocks.

hwa-eggs-alyssa-reid-state-parks
HWA egg sacks on an Eastern Hemlock branch. Note the two white lines on the underside of the needles. Photo by Alyssa Reid, NYS Parks.

Checking for HWA is easy – simply flip a hemlock branch over, and scan the base of the needles for the presence of white, woolly, round egg-sacks. While some larger hemlocks have branches that are un-reachable, many of the smaller trees have overhanging branches that can easily be reached without leaving the trail. Take note of where you are, and anything that looks suspicious (many smart phones will even allow you to save your location), and let Parks staff know where you found HWA before you head home for the day.

State Parks Invasive Species Field Control Director, Bob O’Brien, demonstrates surveying techniques to volunteers at Allegany State Park. Photo of Alyssa Reid, State Parks.
Volunteers at Allegany State Park employ an innovative technique to reach a hemlock branch and check for HWA. Photo by Alyssa Reid, State Parks

So, as you head out on the trail this season, consider pausing from time-to-time to inspect a nearby hemlock branch or two. NY State’s hemlocks need our help, and you can play an important role in conservation, while enjoying the outdoors!

For more information, or to find out how to volunteer and learn more about HWA and invasive forest pests, contacts NYS Parks Invasive Species Staff: 845-256-0579.

hwa-survey-alyssa-reid-state-parks
HWA surveys are an important way to help out, while exploring New York’s winter wonderland. Photo by Alyssa Reid, State Parks

Post by Sarah Travalio, State Parks

Park Personnel, Park Projects

Forest Health Specialists: Climbing in Pursuit of Invasive Insects

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Forest Health Specialists are an important part of New York State Park’s Invasive Species Management Team. Their work helps protect native plants, wildlife  and forests that are currently being threatened by two non-native invasive species: Hemlock Woolly Adelgid (HWA) and Emerald Ash Borer (EAB). Although these insects are very different from each other in appearance and behavior, they both cause significant destruction and mortality to their host trees.

Hemlock Woolly Adelgid on hemlock stems. Look for small, white, cotton-like blobs on the underside of hemlock branches, right at the base of the needles.
An adult Emerald Ash Borer emerging from an ash tree. Note the “D” shaped hole the insect has created, which is a sure sign you’ve found EAB.

What do Forest Health Specialists Actually Do?

The Forest Health Specialists are seasonal employees that travel throughout New York State conducting invasive species surveys and monitoring infestations in various Parks. They have training in field biology, forestry, and tree climbing. The team of two camps at the park of interest while completing their work. Surveys involve lots of hiking and investigating trees that look to be in poor health, taking photos, and recording information on location and observations made at each site.

Although hiking in the woods isn’t a bad way to spend a work day, monitoring infestations of HWA is where the job really gets interesting. Specialists need to collect canopy samples from hemlock trees in order to see if insect numbers are declining or increasing. So, using a giant 8-foot slingshot, a line is shot high into the tree to a branch anywhere between 50 to 90 feet above the ground. Then a climbing rope is attached and pulled into the canopy and the fun begins! The Specialist, equipped with a harness and two ascenders (the name for special clips), climbs the rope upwards into the treetop. Climbing can be highly physical but is always rewarding.

3
A Forest Health Specialist working their way up to the canopy using a climbing harness that is attached to the rope. Climbs typically take about an hour.

4
A bird’s eye view looking down from the top of a hemlock. The tiny speck at in the bottom (in the green shirt and white cap) is the other team member!

So What’s the Goal?

The goal of this program is to get a better grasp of where these invasive species are spreading, assessing their impact on the forests, and ultimately taking action to slow their spread and keep their numbers under control. It also allows biologists and managers to anticipate other impacts to wildlife or rare species; to plan for potential avoidance or removal of hazard trees along trails; and to help others understand changes they see in the forest and landscape around us.

Of course a key component to the program’s success is you! By offering educational programs and volunteer opportunities, Forest Health Specialists also help people all over the state learn about invasive insects. The more people participating in and understanding invasive species in New York; the better chance we have of making a difference in our parks and our communities.

Remember, the best way to stop the spread of Emerald Ash Borer and Hemlock Woolly Adelgid is to avoid introducing them in the first place. Don’t move firewood, take caution in moving landscaping debris around, and clean equipment and vehicles if moving from a site with these pests to somewhere else!

For more information go to NYS DEC website:  www.dec.ny.gov/animals/265.html

Post by Kelly Blood (OPRHP). Photos by Kelly Blood and Alyssa Reid (OPRHP).