Hemlock pest advancing

ACADIA NAT’L PARK — After a report of a confirmed sighting of the wooly adelgid in Camden late last week, park officials are asking residents to be on the lookout for the small aphid-like insect. Once an infestation takes hold, the pests can decimate an area’s hemlock trees.

During most of the year, the insect’s body, which is covered by white, waxy tendrils, looks like a cotton ball and is found on young twigs.

The Maine State Forest Service reported late last week that the wooly adelgid was recently found by a tourist on two stately trees in Camden. While the Forest Service believes the pest is not limited to the two in-town trees, it is unclear whether the insect has infested the forests in and around Camden.

The insect, which came from Japan in the 1950s, can be found year round, but is most abundant in spring when the egg masses are present. As they feed, the wooly covering expands. These insects suck sap from trees, and while feeding, inject a toxic saliva. Once hemlocks are infested, needles drop prematurely and twigs dieback. Infected trees are more susceptible to disease and attract wood-boring insects.

In Maine, the insect has been found primarily in coastal areas from Kittery to Camden. Earlier this year, the insect was found in Friendship and Owls Head during an aerial detection survey.

According to a Maine Forest Service fact sheet, woody adelgid in this area produce two generations each year. The adults that overwinter lay eggs in March and April. When these eggs mature in late spring, they each can deposit up to 75 eggs. While they are dormant for some time, in mid-October, the feeding resumes, and the insects are again covered in a white, wooly substance.

Any residents who suspects that their hemlocks are infested are asked to report it to the Maine Forest Service at 1-800-367-0223.

Anne Kozak

Anne Kozak

Contributer at Mount Desert Islander
Anne teaches writing at the College of the Atlantic in Bar Harbor.
Anne Kozak

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