Attack of the hemlock woolly adelgid


eastern hemlockis considered by many to be the most characteristic evergreen tree of our region. It grows in cool, shady, moist forests and on the slopes of our hills and ravines, often in extensive stands.


A mature hemlock can grow to at least 70 feet in height and live for hundreds of years. The tree's shape is conical, with slightly drooping branches growing nearly down to the ground. The needle-like leaves, unlike those of pines and spruces, grow in flat, double rows. Years ago a naturalist taught me that if you take a few needles and crush them between your fingers, you get a delicious, resiny aroma.

Ecologically speaking, the hemlock is an important tree in our forests, providing shade and shelter for wildlife in all seasons.

White-tailed deerfeed on hemlock leaves. Eastern screech-owlsand saw-whet owlsmay be found roosting within the dense foliage. The shade along streams also helps keep the streams cool - important for fish favored by anglers - and hemlock stands stabilize soil and help purify water that feeds wetlands. The hemlock is also a popular ornamental tree in dooryards and gardens.


But, like the

American chestnutthat I wrote about a while ago, the eastern hemlock has been devastated in the past two decades by an introduced pest, a small aphid-like insect imported from Japan known as the hemlock woolly adelgid. The adelgid feeds on the leaves at their joints, turning them brown and weakening the tree.


A mature hemlock can die from adelgid infestation within four to six years. Many forests throughout the state, particularly in the eastern half of Connecticut, have been hard hit. The adelgid is a relative newcomer to the Northwest Corner; our towns were among the last in the state to receive the pest, which now covers the entire state.

Fortunately, a biological control agent pioneered for use by our very own Connecticut Agricultural Experiment Station (CAES) has shown promising signs of being able to manage the adelgid and restore hemlock forests. The agent is also a Japanese import, a species of

Asiatic ladybeetle - fortunately, not the same one that homeowners in our area know as the bright orange pest that gathers in occasional breakout numbers on walls and ceilings. This one's much smaller, and black. It is presumably a natural predator of the adelgid in Japan, and seems to be adjusting to a similar role here.


Dr. Carole Cheah of the CAES has guided the adelgid control project in Connecticut. Close to 200,000 beetles have been released in the state so far, and initial indications are that some of the mostly heavily damaged areas are showing signs of recovery. We can only hope that the introduction of the ladybeetle in our area will head off the problem before we lose our lovely hemlocks.


Fred Baumgarten is a naturalist and writer. He can be reached at His blog is at 


Latest News

Robert J. Pallone

NORFOLK — Robert J. Pallone, 69, of Perkins St. passed away April 12, 2024, at St. Vincent Medical Center. He was a loving, eccentric CPA. He was kind and compassionate. If you ever needed anything, Bob would be right there. He touched many lives and even saved one.

Bob was born Feb. 5, 1955 in Torrington, the son of the late Joesph and Elizabeth Pallone.

Keep ReadingShow less
The artistic life of Joelle Sander

"Flowers" by the late artist and writer Joelle Sander.

Cornwall Library

The Cornwall Library unveiled its latest art exhibition, “Live It Up!,” showcasing the work of the late West Cornwall resident Joelle Sander on Saturday, April 13. The twenty works on canvas on display were curated in partnership with the library with the help of her son, Jason Sander, from the collection of paintings she left behind to him. Clearly enamored with nature in all its seasons, Sander, who split time between her home in New York City and her country house in Litchfield County, took inspiration from the distinctive white bark trunks of the area’s many birch trees, the swirling snow of Connecticut’s wintery woods, and even the scenic view of the Audubon in Sharon. The sole painting to depict fauna is a melancholy near-abstract outline of a cow, rootless in a miasma haze of plum and Persian blue paint. Her most prominently displayed painting, “Flowers,” effectively builds up layers of paint so that her flurry of petals takes on a three-dimensional texture in their rough application, reminiscent of another Cornwall artist, Don Bracken.

Keep ReadingShow less
A Seder to savor in Sheffield

Rabbi Zach Fredman

Zivar Amrami

On April 23, Race Brook Lodge in Sheffield will host “Feast of Mystics,” a Passover Seder that promises to provide ecstasy for the senses.

“’The Feast of Mystics’ was a title we used for events back when I was running The New Shul,” said Rabbi Zach Fredman of his time at the independent creative community in the West Village in New York City.

Keep ReadingShow less