On a mission to save hemlock trees from pests

Hemlock woolly adelgid, which is a aphid-like insect that threatens the health of hemlock trees, was spotted by Hocking Soil and Water Conservation District employees a few years ago. The impacted trees were destroyed as the HWA feed on plant fluids, which is crucial to the tree’s growth and survival, according to experts.

LOGAN — After treating 5,000 eastern hemlock trees in Hocking Hills State Park and beyond, the Ohio Department of Natural Resources (ODNR) Division of Forestry is urging locals to be on the lookout for signs of hemlock woolly adelgid (HWA) until early May.

The Hocking Hills Conservation Association recently met to discuss the findings of HWA in the area and ways to get the message out for folks to keep their eyes open while hiking. They came up with a brief public service announcement to be handed out to area residents in a postcard format.

“We sent those out to kind of give people an idea of what to look for on their property and that went to everyone who had been identified as possibly having hemlocks on their property or in the surrounding area,” explained Rebecca Miller, education specialist with the Hocking County Soil Water Conservation District.

“Then if they find it they can call our office to say that they may need assistance or if they’re unsure if they have it, we can get someone out there to take a look at it,” she added.

Hemlock woolly adelgid is a very small aphid-like insect that’s attracted to hemlock trees. Developing nymphs and adults take their straw-like mouth into the base of the hemlock needles where they feed on sugars stored in the foliage.

Most often they’re found on the undersides of hemlock needles from October through May. They produce white, woolly cotton-swab-like coverings on the branches.

Because HWA was introduced relatively recently, there are no native predators of HWA in eastern North America to significantly limit its population growth, according to the Ohio Department of Natural Resources website.

A major cause of death for these little guys is the cold winter temperatures, which is one of the reasons trees are killed quicker in southern areas rather than more northern areas. Trees can survive as little as four years with HWA or at the most 15 years with the insects feeding on them.

In the early 2000s is when HWA was first found in the Carolinas, but before the state could get a handle on the invasive species, it was too late. That’s when local organizations like Hocking County Soil & Water Conservation District and others began to work together on how to get ahead of the issue.

In 2013, the first signs of HWA was discovered in the Hocking Hills region toward Cantwell Cliffs. Since then, they’ve tackled the species with chemical treatments because it’s ultimately more effective. Because of this, they haven’t seen a decrease in the amount of hemlocks like in the Smokies.

Symptoms of HWA vary, but they commonly include needle loss, discoloration and gray-tinted foliage. Many residents have begun creating an Eastern Hemlock Conservation Plan or attended public workshops about HWA. ODNR encourages landowners to contact the Division of Forestry for assisting a conservation plan or to visit Hocking County Soil and Water Conservation District.

Since 2013, more than 7,000 beetles have been released at several sites in southeastern Ohio to help address isolated infestations of HWA. In 2018, more than 1,600 beetles were released at Lake Katharine State Nature Preserve in Jackson County as part of a comprehensive plan to reduce the impact of HWA. ODNR also completed an Eastern Hemlock Conservation Plan in 2017, which is being used to guide the management of HWA.

Most recently across 1,400 acres, ODNR chemically treated thousands of trees in order to protect high-value hemlock forests from the damaging invasive insect of HWA. Whether in the backyard of a home, in local or state parks, these tiny insects can create unsightly damage to the beloved eastern hemlock trees over time.

When treating the hemlocks, systemic insecticides are injected into the tree, applied to the soil near the trunk, or sprayed directly on the trunk. The insecticides are highly effective in protecting trees for five to seven years. These treatments are the best rapid response measure available to keep hemlocks healthy and the treatments are harmless to trees and people.

How you can help:

• Take a walk this winter and early spring to locate hemlock trees in your woods;

• Carefully inspect low-hanging hemlock branches for white woolly masses of HWA;

• Let ODNR know where you looked and what you found.

The online reporting system is also a helpful tool for folks to monitor the area, noted Miller, who said even if they don’t have it, still put your findings on the reporting system so they know when the area was checked.

“The main point is to keep it in the forefront so people don’t forget about it. It’s not something you want to skip a year and not check your property for,” added Miller.

For more information or to report your findings on HWA visit OhioDNR.gov/HWA, email OhioHWA@dnr.state.oh.us or by calling 740-385-3016. The Hocking County Soil Water Conservation District is the local resource for reporting findings of HWA.

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