Our Catskill Hemlocks Hemlock Wooly Adelgid, Education and treatment options August 30th, 2019

Table of Contents Benefits of Hemlocks to our landscape The Hemlock Wooly Adelgid (HWA) Introduction Identification Treatment Close Appendix Contact information Resources

Benefits of Hemlocks to our landscape

Hemlocks are a very beneficial tree to the Catskills Hemlock trees are a key component of the canopy forest in the Catskill area of New York State. They provide the deepest shade on the East Coast. Among their many benefits, Hemlocks: Grow in steep slopes and poor soils of our streams and lakes, providing shade/cool waters where fish thrive, and reducing run-off into our waterways Where Hemlocks are lost, fishing and water quality decrease due to increased nutrient loads (Brook trout are 4x larger in Hemlock-shaded waterways) Hemlocks provide forage areas for deer, birds, porcupines, and many woodland animals, catching snow in winter providing open ground for animals to feed Hemlocks provide needed nutrients to acidic soils Hemlocks draw-up water, preventing snow melt flooding

The Hemlock Wooly Adelgid (HWA)

The Hemlock Wooly Adelgid The Hemlock Wooly Adelgid (HWA) was introduced to the US in 1951, likely from garden ornamentals imported from Japan, and spread to NY in the early 1990’s There is a different variety of HWA on the West Coast, that was introduced from China 25-30% of the East Coast is infected with HWA, including Sullivan Country, NY HWA is spread by wind, mammals, birds, humans Trees infected with HWA are more susceptible to drought stress Without treatment, trees infected with HWA will die within 6-10 years

Identifying the Hemlock Wooly Adelgid HWA live at the base of needles, typically on the underside on a series of branches You’d need a 10x magnifying glass to see the eggs and nymphs, but can see the wooly covered adult HWA with your bare eyes The HWA suck the starch reserves from the tree at the base of the needle and inject their saliva, the tree has hyper-sensitivity to this which kills the water movement, and then over the long-term, kills the tree You’re more likely to see the wool in fall and late winter April and Sep/Oct are most likely time to spread the HWA, as the aphids are at various crawling stages Early infestations typically take place in the upper canopy, making it harder to ID

Treating the Hemlock Wooly Adelgid There are treatments for HWA: The most common treatment is spraying or tree injections, using various insecticides, that should be applied by a certified arborist Optimal treatment times are spring and fall You need to treat forever, but you don’t have to treat every year Biocontrol is the most promising option for long-term treatment and for sustaining the Hemlocks Several beetle releases are being tested in NY State under rigorous conditions to ensure there is no chance of host switching; there have been successful releases in PA, WV, VA ad TN There is a lot of optimism for a breed of silver fly, whose larvae feeds on HWA eggs This is being tested in multiple NY locations, although there is no firm establishment yet Tree hybridization has been tried, with little success The wetter the area, the stronger the Hemlocks are

In closing….and how we can help Unfortunately, the HWA is here to stay…the good news is that in certain parts of the country, a beetle that eats the HWA has been introduced and is thriving In the near term, the only way to save Hemlock trees is to treat them – the HWA can be successfully treated with insecticides – treat the trees you wish to keep Group rates are available for arborist who are hired to treat many trees at one time The NY State Department of Environmental Conservation (DEC) & Cornell NEED OUR HELP Tree surveys - http://nyis.info/invasive_species/hemlock-woolly-adelgid/ Volunteers for treatment programs – Cornell is looking for 8-10” tall hedgerows for field testing Providing food for their beetle populations – Cornell will pick-up infested tree branches

Appendix

Resources All information in this presentation comes from notes taken at the New York Department of Environmental Conservation educational meeting, attended June 13, 2019, in Woodstock, NY, by James & Lori Harr Visit NY DEC website for information and additional fact sheets on HWA, https://www.dec.ny.gov/animals/7250.html Also, Cornell has a wonderful Hemlock conservation program, led by Mark Whitmore https://blogs.cornell.edu/nyshemlockinitiative/hemlock-woolly-adelgid/why-hemlock- trees/ https://blogs.cornell.edu/nyshemlockinitiative/home/our-team/ Someone from the NY DEC will come to our club to speak on the HWA if we’d like them to – contact Lori Harr if interested Double-click icon to open fact sheet

Hemlock Q&A Q: At what point of infestation should you remove the Hemlock tree? A: In areas that have been commercially thinned, and therefore have increased light on the trees, have seen a decrease in HWA – but there is no specific time recommended for tree removal Q: How do you dispose of infested tree parts? A: Leave the branches on the ground, in the woods near the tree, do not move them to a new area Q: Is it worth it to treat your trees if others near you are not? A: Treat the trees you wish to save

Image of an infested Hemlock forest Note the graying die-back

Extent of Eastern Infestation as of 2017