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 First detected in VA in1951  Has since been found in 17 states  Moves slowly  Follows Water Courses  Movement by:  Tree-to-tree  Birds  Wind

They feed on the xylem of the tree, killing the foliage and buds. Once Hemlock Woolly Adelgid infects a tree they go into a boom & bust cycle where there population explodes and collapses, weakening the tree over time. Eventually within 4 to 10 years you will see tree mortality- older trees dying first. Mortality is slowed here because of colder winters, but inevitable! What does this pest do? …

 HWA is already established in about half of the hemlock range in the eastern US Damage  In some places like Shenandoah National Park it has killed over 80% of the hemlocks.  Vast mortality rates drastically shift the forest  species composition and alter ecological processes such as nutrient cycling and stream temperatures.  Extensive hemlock mortality leads to a loss of hemlock-dependent wildlife. Song birds are especially at risk.

Infestation Spread

USFS, Northern Research Station Slide by Mark Whitemore

survey area

 Hemlocks are the 4 th most numerous tree in NY.  Hemlocks are ecologically valuable:  provide important wildlife habitat.  stabilize shallow soils.  help shade streams & lakes, making water more suitable for trout.  Hemlocks are also aesthetically valuable, they are a beautiful part of the Catskills.  If the Hemlocks die, open canopies will promote the spread of invasive plants.

Slide by Mark Whitemore

How to ID Hemlocks, the Emerald Ash Borer and an EAB infestation © Lexa Panessidi, State of Michigan, forestryimages.org - UGA Photo courtesy of Dr. David Roberts, Michigan State University

1.Leaves needle-like--go to 2 Leaves not needle-like--not hemlock 2. Leaves attached to twigs in clusters--not hemlock (pine or larch) Leaves attached singly--go to 3 3. Leaves angled in cross section --not hemlock (spruce) Leaves flat--go to 4 Hint: Try rolling the needles between your fingers. Spruce needles (angled) will roll, hemlock and fir needles (flat) will not. 4. Leaf sides tapered, twigs flexible, leaf attached to small "peg" on the twig, leaf with small stem*--HEMLOCK* Leaf straight-sided, twigs stiff, leaf attached to twig with suction-cup-like attachment--not hemlock (Fir) Guide adapted from the Maine Forest Service

HEMLOCKFIR

D’Amico and Havill, 2012

Crawler is the ONLY dispersal stage Nymph inserts mouthparts then enters diapause for summer Kelly Oten, Bugwood.org

Hemlock Woolly Adelgid Adelges tsugae

Parthenogenetic (all females) Remarkable reproductive potential 2 generations per year & up to 300 eggs/female 1 x 200 x 100 = 20,000 potential progeny from 1 female/yr. Natural enemies are lacking in the eastern US No documented resistance by Eastern hemlock hosts No area-wide treatments are available Difficult to detect at low population levels Slide by Mark Whitemore

When looking for Hemlock Woolly Adelgid Don't be Fooled by These Imposters.

Elongate Hemlock Scale is another invasive insect pest that people may mistake for HWA. It is also very damaging to trees and should be managed if found to be present.

Management Options

Systematic injections of pesticides Insecticidal oils and soaps Biocontrol insect releases Fungal biocontrol Resistant hybrids

For small trees horticultural oil sprays and soaps are a great option. Trees under 30 ft tall can be treated by homeowner themselves. Pesticide-based methods can also work for large individual trees or small tree stands. Although soil drench options are available for use by home owners, to support pesticide safety we encourage home owners to seek the help of a specialist.

Other good Practices  Maintain tree health by irrigating trees during prolonged dry periods and remove dead or dying limbs.  Never fertilize Adelgid-infested trees because adelgids thrive on fertilized trees.  HWA can be moved from tree to tree by songbirds, so bird feeders should not be placed near hemlocks.  Oil sprays and soaps do not act as deterrents and should not be used on trees that free from infestation.

 These sprays must thoroughly cover the insects to kill them so the foliage, twigs, and branches must be sprayed almost to the point of runoff.  The products do not leave a toxic residue and several applications may be needed.  Make sure coverage is thorough or surviving HWA soon will re- infest the tree.  It is best to apply the sprays when the HWA are at a life state without a protective covering. Following egg hatch from March through April and from September to October.  Insecticidal soaps and horticultural oils can be used in sensitive sites near houses, creeks, or ponds without risk to non-target organisms or the environment.

Three basic application techniques: Soil drench or injection (Imidacloprid) Only homeowner product is a soil drench Possibility of surface water contamination Bark spray (Dinotefuran) Rapid application and uptake Trunk injection (Imidacloprid, Emamectin benzoate) Can be time consuming Limited environmental exposure

 Imidacloprid  Various formulations and application techniques  Time release tablets restricted use  Soil drench available to homeowners  Effective for 7 years or more  Slow to move through tree  Dinotefuran (Safari)  Basal bark spray, Fast movement in tree. 1 or 2 years  Azidiractin (TreeAzin)  Environmentally benign. Control for 1 year or more.

Chemical control becomes difficult/costly with larger stands. Biological control offers the only effective long-term solution. Although the most effective long-term treatments may be a combination of chemical & Biological control.

Biological control seeks to restore system balance by establishing enough predators to keep an invasive pest in check. Before an insect is released it must be given FONSI (Finding Of No Significant Impact) status by the USDA. To achieve FONSI status a biological control agent must complete rigorous testing to insure its safety for release. Photos by Mark Whitemore

To date there have been multiple predators released in many areas from Maine to North Carolina. Sasajiscymnus tsugae (formerly Pseudoscymnus tsugae)- is native to Japan. Released in Since 2002 more than two million S. tsugae beetles have been reared and released in the eastern US. Now commercially available. Laricobius nigrinus- first collected in British Colombia, Canada. Mark Whitemore at Cornell has been working on releases in NY. Laricobius osakensis and Scymnus camptodromus are both relatively new, few releases so far. Scientists are still working on how to better rear them. They look very promising. Photos by Mark Whitemore

The most successful predators have been Laricobius nigrinus and Sasajiscymnus tsugae. The most popular to date in New York State is Laricobius nigrinus. Biological control in New York state is still relatively undeveloped. Tests in Connecticut and Virginia have shown releases of Sasajiscymnus tsugae to reduce HWA populations by 47 to 87 percent in five months. Results are compounded by the fact that many of the releases have not looked into the survival and efficacy of the predators.

General fungal insecticides been found to be effective at controlling adelgids. However fungal sprays are generalized; they kill many insects, not just adelgids. Photo by Mark Whitemore

What needs to be done? State wide public & private initiatives to help manage and save our Hemlocks. This involves identifying high priority stands Finding the fringe areas on the 'leading edge' of the infestation. Interagency & private cooperation. Work across boundaries. Getting local small landowners involved A combination of chemical/biological control may be necessary to help save NY Hemlocks.

Spread of Hemlock Woolly Adelgid is still relatively low in NY state. Now is the time for action. If we wait until the infestation spreads and becomes more serious, it will be too late. Biological control will not work on highly infested trees. Even with biological control saving Hemlocks is a long term goal a year project. 10 years is not enough. Cold snaps in New York have made it harder for HWA to establish, but they might also make it harder for predators of HWA to establish.

HWA Community Outreach & Survey Methods

Benefit of raising general awareness of Hemlock Woolly Adelgid for all constituents in the Catskills Region. What is HWA, how should homeowners manage it, what can people do to help. We can direct homeowners to information on how to protect their trees: pdf pdf

We can pool our interested base of constituents to help us complete HWA surveys. Fly-over data from the Forest Service can help us target what areas to survey. On the ground data is useful for gaps in fly-over data and for quantifying areas suitable for biological control releases.

NYDEC has an Hemlock Woolly Adelgid volunteer survey form and procedure set to follow available online. Forms are submitted to the DEC which compiles the information for a HWA database. A summary map of the data is available online at: Following this protocol can help us to streamline the data collected. Citizen involvement can get the local community to care and can help us plan bio-control release sites.

Photo by Mark Whitemore