Tag Archives: Emerald Ash Borer

Forest Health Specialists: Climbing in Pursuit of Invasive Insects

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.

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.

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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.
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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).

 

Emerald Ash Borer and the Polar Vortex

Damage to an Ash trunk by Emerald Ash Borer larvae
Damage to an Ash trunk by Emerald Ash Borer larvae. Photo by NYS Parks

It’s certainly been cold this winter, but current low temperatures, combined with the recent effects of the polar vortex, may deliver unexpected benefits this spring. Foresters and scientists in New York have been fighting against the rapid expansion of the Emerald Ash Borer, an invasive insect which kills ash trees in alarming numbers. The long winter freeze may provide a much-needed advantage against these tiny invaders.

The emerald ash borer is a beetle which arrived in the United States on untreated wood pallets used for shipping from China. In Asia and Russia, the emerald ash borer is kept in check by predators and the natural resistance of ash trees which have had thousands of years to adapt defenses against this parasitic insect. American ash trees, however, have no defenses against this exotic species.

Since they were first identified in Michigan in 2002, emerald ash borers have expanded across the Northern and Eastern United States and killed over 50 million American ash trees. In 2009, these pests were first identified in New York’s Cattaraugus County, posing a new and potentially devastating threat to New York’s forests.

Emerald ash borers kill ash trees by boring underneath the bark into order to lay their eggs. Once hatched, larva feed upon the tree’s living tissue, killing it slowly over the course of 2-3 years.

In wintertime, ash borer larva shelter underneath the bark of ash trees, however, extreme cold temperatures, like we have been experiencing, can freeze the larva even underneath the bark layer and slow down the population growth of this pernicious pest. However, it takes more than just a few hours below zero in the morning to hurt EABs, but sustained sub-zero temperatures could potentially kill a significant portion of the Emerald Ash Borer population. Because EAB larvae shelter deep under the tree’s bark at the base of the trunk and even in the upper roots, where a snow layer can keep them insulated from extreme cold and the tree itself regulates their temperature, they are relatively adept at surviving in cold climates.

For example, this winter at Taughannock State Park near Cayuga Lake, the temperature was never recorded below -8°F (-22°C) and we found Hemlock Wooly Adelgid, another pernicious invasive insect, mortality to be about 88%. On the other hand, at Mine Kill State Park in the northern Catskills, temperatures got to -24°F (-31°C) and we found only about 72% mortality.

For this reason, we can expect the polar vortex to temporarily slow down the expansion of EAB, but management and surveying efforts will continue to be necessary into the future.

Similar:

Invasives and Cold Weather in NY, Cornell University Cooperative Extension.