Thursday, January 23, 2014

Invasives In Winter: A Trip To Lake Durant

binocularsOn a frigid morning in late December, I teamed up with a good friend and hiked the Lake Durant campground in Indian Lake in search of aliens. We were not on the lookout for little green martians, but invasive insects.

I met Tom Colarusso of the United States Department of Agriculture’s Animal and Plant Health Inspection Service in the campground parking lot. It was a windy day and the vehicle swayed a little as I dug around the back seat in search of my hat and gloves.

I was armed with a GPS system to document coordinates in case something suspicious was found, and tucked a pen and pad into my pocket for notes. Tom looped a pair of binoculars around his neck and then we were off. 2013 marked our fifth year of teaming up to survey Hamilton County’s forested areas for alien invaders like Asian longhorned beetle and emerald ash borer.

The Adirondacks receive between 7 and 10 million visitors a year, according to Tom. Some of these visitors go camping, and although there are state and federal laws regulating movement of wood, the possibility remains that infested firewood is being brought in. For this reason, it’s important to survey and monitor for invasive forest pests. Early detection and rapid response are crucial in the fight against invaders.

Both the Asian longhorned beetle and the emerald ash borer are native to Asia, and probably hitched a ride to the United States in wood packing material. Without the ecological checks and balances found on their home turf, they rapidly reproduce. Larvae feed on the tree’s living tissue, cutting off the tree’s food and water transportation systems. With aggressive infestations, trees can die in a few years. Emerald ash borer attacks ash species including white, green, and black. Host trees for the Asian longhorned beetle include 13 trees such as maple, elm, willow, and birch. Emerald ash borer is close to Hamilton County in Albany and Onondaga Counties among other New York State locales. Asian longhorned beetle has been found in the New York City boroughs of Brooklyn and Queens, as well as an area on Long Island, and even closer in Worcester County, Massachusetts.

epicormic sproutingTom and I inspected trees for signs of infestation. We looked for woodpecker damage, which is a good lead to an insect problem. Tree bark was scanned for exit holes and egg laying sites. Asian longhorned beetles make round exit holes that are deep enough to hold a pencil in, while emerald ash borers chew small, D-shaped exit holes. We were also on the lookout for epicormic sprouting, or new branches produced by a tree when it is stressed. Vertical bark splitting is another red flag of invasion. Winter is a good time survey trees because signs and symptoms of infestation are not hidden by foliage.

Tom and I often target campgrounds for survey areas because campers may accidentally transport insect hitchhikers in firewood that they bring to their vacation destination. Untreated firewood may travel hundreds of miles across state boarders, harboring invasive bugs and disease. In an effort to prevent the spread of harmful pests, the Department of Environmental Conservation has issued a regulation that prohibits the movement of firewood into New York State unless it has been heat treated. The regulation also restricts the transportation of untreated firewood to no more than 50 miles from the source within the State.

After a full morning of hiking and looking to the tree tops, Tom and I were happy to find no signs of Asian longhorned beetle or emerald ash borer in the Lake Durant campground. However, I was bummed (but not surprised) that beech bark disease was prevalent. This disease is caused by beech scale, which attacks the bark, making trees susceptible to fungal invasion. I’ve seen it every year during our surveys.

I asked my friend Kevin Elkin, owner of Kevin Elkin Tree Service, to describe his experience with beech bark disease. “Beech Bark Blight is everywhere within the area I work, which goes as far south as Hope and as far north as Newcomb,” he said. “It’s rare for me to find a beech tree 12” diameter at breast height that does not show signs of beech bark blight. Most beech trees I find that are 16” dbh or larger are usually falling apart from beech bark blight, and few grow to be much larger.”

Beech bark disease is caused by the beech scale insect that attacks the bark, making trees susceptible to fungal invasion.  “Most beech trees I remove are being removed because of beech bark blight,” Kevin explained. “As the disease runs its course, the tree becomes very unstable. It becomes challenging to do removals, because the tree can fail anywhere, from the base to the top. It may well put out a nearly full canopy of leaves (with the exception of the most affected areas of the tree that have obviously dead limbs), which makes customers believe it is a healthy tree. For this reason, people wait too long to call a tree service to have their trees looked at.”

Tom and I get together for at least one survey a year, because public safety is protected and tax payer dollars are saved when forests remain invasive free. Invasive insects weaken trees, and limbs may fall on cars, homes, or power lines. Tree removal is expensive. These beetles threaten the baseball bat, maple syrup, lumber, nursery stock, paper, and tourism industries, with potential loss amounting to billions of dollars.

To help stop the spread of invasive insects don’t move firewood – burn it where you buy it. Learn the signs and symptoms of invasive insects, and check your trees regularly for forest pests. With these easy steps, forest health can be protected for future generations.

To learn more about invasive pests and how they are moved into and around the country, visit APHIS Hungry Pests and the UDSA’s Asian Longhorned Beetle website. You can also watch the video “Invasive insect forest surveying: a how to guide for emerald ash borer and Asian longhorned beetle” at YouTube.

Photos: Above, Caitlin at work at Lake Durant Beech; middle, epicormic sprouting; and below, trees showing signs of beech bark disease.


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Caitlin Stewart manages the Hamilton County Soil and Water Conservation District. The District's mission is to manage and promote the wise use of Natural Resources in Hamilton County. Caitlin will be sharing the District's conservation-focused services, programs, and events. She’s been a full time resident of Hamilton County since 2008 and is an avid hiker, skier, paddler, and biker. She is obsessed with adventuring with her dog Artemis.

14 Responses

  1. Pete Klein says:

    Keep up the good work, Caitlin

  2. Caitlin Stewart says:

    Thank you very much, Pete! I feel so fortunate to be involved with invasive species projects like this. Stay warm out there and have a terrific weekend.

  3. Paul says:

    As I understand it the Emerald Ash Borer was transported from Asia to NA via wooden shipping pallets. Caitlin the firewood ban makes sense but has there actually been any documented spread of one of these invasives via firewood? If, no, perhaps it is because of the ban? Has it been documented elsewhere? What is the science behind the ban?
    Also, do you have any idea what is the current management plan that the DEC has when, and if, these insects are discovered on Forest Preserve land in the Adirondacks? With the traps (and work like you are doing) we are looking for them. What do we do if we (unfortunately) find them?

  4. Bill says:

    Try this site:

    All one could want to know with photos, maps, history – just follow the links.

  5. Hillel B says:

    Great article! Keep up the good work!

  6. Caitlin Stewart says:

    Paul – you have raised some excellent questions.
    1. Has there actually been any documented spread of one of these invasives via firewood?

    At all of the invasive species meetings, seminars, and webinars I have attended, firewood is a major spread mechanism for invasive insects. I conducted a quick Google search and found this paper “Dispersal of Emerald Ash Borer: A Case Study at Tipton, Michigan –” that concluded an emerald ash borer infestation originated from firewood. Here is working paper ( that indicates firewood is the “primary mode of new emerald ash borer infestations.”

    2. “Also, do you have any idea what is the current management plan that the DEC has when, and if, these insects are discovered on Forest Preserve land in the Adirondacks? What do we do if we (unfortunately) find them?”

    Paul, this is a great question for the Department of Environmental Conservation, Adirondack Park Agency, or the Adirondack Council.

    3. Has it been documented elsewhere?

    Here is a map of EAB infestations from Emerald Ash Borer Info:

    Follow this link for information about Asian longhorned beetle infestations in the Northeast:

    What is the science behind the ban? – See more at:

    4. For more information:

    Bill, thank you for sharing the DEC website for EAB:

    Here is a link to the DEC’s Asian longhorned beetle page:

    • Paul says:

      Wow, thanks! This is great.

      I heard a story recently on NPR about some of these insects (larvae in the trees) can be killed by sub zero temperatures. This past week may have done the trick on getting rid of some of these if they were around up there. I think the said that 20 below would kill 50% (not bad) and 30 below could lead to 100% mortality.

    • Paul says:

      Thanks. On number 3 you answered it above. I was asking about cases of firewood spreading the little buggers! It looks like there is good evidence of that.

      This has been quite devastating in Michigan.

      By the “science behind it” is also what you said above. It sounds like firewood is a proven transporter of the invasive.

      I wonder about all these ash logs we see being trucked all over parts of NYS. It seems like places have also maybe decided to log off their ash trees before it is too late.

      One last question. Can this bug live in things like Mt. Ash? It would be sad to see it hit those trees as well.

      As far as the DEC plan I guess I would have to ask them specifically it appears there is no plan documented in any of their online information. All about surveillance and nothing about action when it hits.

  7. Caitlin Stewart says:

    Bill, thank you for sharing the link to the DEC’s emerald ash borer page!

  8. Caitlin Stewart says:

    Hillel B, thank you very much!

  9. Caitlin Stewart says:


    Here are some links to articles that address cold temperatures killing invasive insects:

    Biocontrol is also being researched:

    “One last question. Can this bug live in things like Mt. Ash?” Research indicates that emerald ash borer only attacks ash trees here in the United States. American mountian ash is not a true ash. Ash fall under the genus Fraxinus while the mountian ash falls under the genus Sorbus. Mountian ash is not a host for emerald ash borer.