Protecting NY Forests from Invasive Species

By Ryan Gregoire, NYSAC Legislative Director

NYSAC recently published a podcast episode of County Conversations featuring Mark Whitmore, the principal investigator and founder of the New York State Hemlock Initiative. Mark is a forest entomologist with the Department of Natural Resources at Cornell University, and he currently works with professional land managers, state and federal agencies, local government officials, and concerned citizens to help them understand the issues surrounding and strategies for minimizing the impact of non-native invasive insects such as the Emerald Ash Borer and the Hemlock Woolly Adelgid.

Interview edited for length and clarity.

RYAN GREGOIRE

Could you give an overall picture of our hemlock forests in NY? Both as a natural resource to all of us in New York, but also serving as a very important recreational and a tourism tool for our state?

MARK WHITMORE

Hemlocks are one of the more important trees in New York's forest. They're the third or fourth most common tree in New York State. Suffice to say that in some places like the Catskills and a lot of the Adirondacks, it really is one of the most common tree species there, and it's important for a number of different things.

It's called a foundation species, and this is a word that basically refers to species that form the basis of the habitat upon which a myriad of other species depend for their survival.

RG

What are Hemlock Woolly Adelgids and how are they threatening forests in New York?

MW

The Hemlock Woolly Adelgid is a little insect. In trying to describe it, I would say it's a millimeter in diameter, like a little beach ball with mouth parts that go into the twigs of the trees. It really became recognized around the 1970s, when it was killing amazing numbers of hemlocks in the Blue Ridge Mountains. It's been in New York State since the 1980s.

It doesn't move really rapidly in New York State, and one of the reasons is that it's susceptible to cold temperatures, and the polar vortex really slowed it down for a couple of years. But now, the past three years have been nice and warm, and I've seen the populations explode and the adelgids start to move into places that we were looking at and getting very worried about.

I feel heartened that the effort that we put in the Adirondacks has really slowed the pace of HWA expansion in the area. Whereas last year, we found some pretty heavily infested trees. Right now, we're sort of like finding little light spots.

RG

Where are we at currently with the insecticides that are currently being used as a short-term solution, and then also long-term with the biological controls?

Our work on the West Coast has shown us very clearly that when you exclude the predators, the Hemlock Woolly Adelgid persists. So, with that information, we're moving full speed ahead to try and bring the predators that are not here on the East Coast from the West Coast and get them established and try and do that in the most efficient manner we can. So basically, since 2008, I've been releasing one of the predators of beetle we call a little Larry.

The other insects we've been working with are something called silver flies. We're hoping that we can get these predators established rapidly enough that they'll be able to control the population so that they don't kill the hemlock trees like they have done throughout the south.

In the meantime, we're very, very fortunate to have some very effective chemicals. And that's what we've been using in areas of high priority, like state parks and in areas like around Lake George. The chemicals are very safe. They're applied just to the tree. The chemicals stay just within the tree. And the beauty is that one application can last perhaps up to seven years or even more. But we can't treat every tree out there, and I don't want to treat every tree. I want to get the long-term solution out there, and that's a biocontrol so we can get off the chemical treadmill. What should county leaders keep in mind going forward?

MW

Climate change is real, and it is impacting the distribution not only of these invasive insects, but also I think it could potentially impact native insects that haven't normally been pests.

We have to pay attention to everything that's out there and really be sensitive to not normal things. And that's what people can do if you see a bunch of trees in your yard, or your wood lot, or your park and all of a sudden something is going wrong with them. Something has affected them. Shrugging your shoulders and just cutting them down is not the right answer. We need to know about it. And when we know about things, then we can actually start to handle it.

It hasn't always been this way. It's like there's been bug problems in the past, but now we're looking at more catastrophic bug problems that come with a price tag added to taxpayers and extra work for county employees.

I think it's important to be aware of these things and not stick your head in the sand saying, well, that's for somebody else to deal with. You can't do everything, but at least be aware of some of the issues that are surrounding you, especially when it comes to maintenance of infrastructure and the placement of trees.