Elongate Hemlock Scale

What is Elongate Hemlock Scale?
(Fiorinia externa Ferris)

Elongate Hemlock Scale (EHS) is from a group of insects known as “armored scales” due to its hard, waxy protective coating. It feeds on the underside of tree needles. EHS prefers hemlock, spruce and fir trees, but will also feed on cedar, pine, and yew. It is still a relatively new invasive pest in Vermont. As of 2023, it has been found in only a few regions of Vermont, primarily around the southeastern portion of the state. 

What to look for? – i.e. Signs and Symptoms

You can find the yellowish to brownish orange scale coverings and light white wool-like substance on the underside of the tree’s needles. Signs of EHS typically appear in the interior of lower branches first and move upward throughout the tree as populations increase. EHS can cause the tree to drop its needles prematurely, cause branch dieback, and in severe infestation cases cause the tree to die. 

Additionally, an EHS infestation can allow the tree to become more susceptible to other pests, pathogens, and stressors such as Hemlock Woolly Adelgid, hemlock borers, fungal root infections, and drought stress.

How does Teacher’s Tree Service manage Hemlock Scale?

• Maintaining and Improving Tree Vigor

• Keeping your tree appropriately watered and ensure it has the nutrients it needs to thrive. Teacher’s conducts fertilization services to maintain the overall health and wellness of your trees. A healthy, properly nourished tree has a better chance of warding off pests and disease. Call us to set up a fertilization. 

• Regular Pruning

• Part of maintaining your tree’s health is a regular pruning schedule. Additionally, pruning may be necessary in preventing spread of EHS to neighboring trees. Teacher’s Tree Service has all the tools and experience to help you keep your tree in tip top health.

• Insecticide Treatments

• If your hemlock tree is already infested with scale, a multi-step treatment plan may be necessary to ensure the recovery and longevity of your tree. Timing of treatments can be critical and may be determined by the level of infestation. Our plant healthcare team can conduct treatments needed. Call us today to set up an assessment. 

I think I have a tree with Elongate Hemlock Scale, what do I do?

Report it! Use the Vermont Invasives Report It! page to report an EHS sighting. We can also help by providing guidance and advice in navigating pest ID, proper reporting channels, and determining a management plan that best fits your tree. Detecting new infestations early is key to slowing its spread to other trees and eradicating it where it has been detected.

We can help you by assessing the overall current health of your hemlock tree(s) and discussing your management options. Our staff of ISA Certified Arborists and ecologists have the knowledge and experience to help you make the best choice for your trees.

Resources

Berrini, Nadine. 2023. “Hemlock-Loving Invasive Insects Are Moving North.” Vermont Land Trust. Vermont Land Trust. December 14, 2023. https://vlt.org/2023/12/14/hemlock-wooly-adelgid/.

Ferreira, Savannah, Alexandra Kosiba, Jim Esden, Dave Adams, Josh Halman, and Rich Holschuh. 2023. “Management Guide for Eastern Hemlock Conservation in Vermont.” Vermont.gov. State of Vermont. https://fpr.vermont.gov/sites/fpr/files/doc_library/Management%20Guide%20for%20EH%20Conservation_0.pdf.

Hoover, Gregory A. 2023. “Elongate Hemlock Scale.” Extension.psu.edu. Penn State Extension, The Pennsylvania State University. April 14, 2023. https://extension.psu.edu/elongate-hemlock-scale.

Klepack, Mollie. 2014. “Elongate Hemlock Scale Found in Southern Vermont.” The University of Vermont. The University of Vermont. December 14, 2014. https://www.uvm.edu/news/story/elongate-hemlock-scale-found-southern-vermont.

Minnesota Department of Agriculture. n.d. “Elongate Hemlock Scale | Minnesota Department of Agriculture.” Www.mda.state.mn.us. Minnesota Department of Agriculture. Accessed February 2, 2024. https://www.mda.state.mn.us/elongate-hemlock-scale.

NH Department of Natural and Cultural Resources , and NH Division of Forests and Lands. 2021. “Hemlock Woolly Adelgid & Elongate Hemlock Scale | NH Division of Forests and Lands.” Www.nh.gov. State of New Hampshire. 2021. https://www.nh.gov/nhdfl/community/forest-health/hemlock-woolly-adelgid-elongate-hemlock-scale.htm.

Vermont Invasives. n.d. “Elongate Hemlock Scale | Vermont Invasives.” Www.vtinvasives.org. Vermont Invasives. Accessed February 2, 2024. https://www.vtinvasives.org/invasive/elongate-hemlock-scale.