MOUNT DESERT — Hemlock woolly adelgid (HWA), a nasty little aphid-like insect, has been discovered by Land & Backyard Protect workers close to the Cobblestone Bridge, a carriage street bridge south of Jordan Pond on the Protect’s boundary with Acadia Nationwide Park.
White and furry in look, the HWA was lately seen coating the branches of enormous japanese hemlock bushes within the space.
“HWA has been spreading for many years by way of the southern Appalachian and mid-Atlantic states and extra lately into New England,” Tate Bushell, director of pure lands on the Land & Backyard Protect, wrote within the Protect’s on-line publication. “In 2003 HWA confirmed up in southern Maine and has been slowly spreading alongside the Maine coast.
“WHA is able to killing its host hemlock tree, and as soon as infestation ranges in an space attain a sure threshold, widespread hemlock dieback is widespread, particularly with out intervention.”
HWA kills hemlock bushes by attaching themselves to the bottom of the needles and sucking the sap out of them.
“Administration choices embrace treating particular person bushes with pesticides, spraying bushes with horticultural oil that suffocates the adelgids and…releasing useful
bugs that feed on HWA,” Bushell stated. “It’s too early to know which administration technique the Protect will pursue, however we’re researching all choices.”
He stated a lot of the bushes that may be seen from the Cobblestone Bridge are hemlock.
“Hemlock that stay alongside streams forged deep shade on the water, which has been proven to reasonable stream temperature in the summertime to the good thing about fish and different aquatic animals,” he stated. “If we lose our hemlock, it can actually influence the ecosystem across the Cobblestone Bridge and can act as a stressor on the forest.”
If HWA isn’t already in Acadia, it’s in all probability only a matter of time, particularly with an infestation now on its doorstep.
Acadia workers wrote in a 2021 article that shade forged by hemlocks creates an excellent surroundings for small freshwater invertebrates.
“These invertebrates are the key meals supply for the numerous completely different species of freshwater fish that we’ve right here at Acadia, similar to brook trout,” they wrote.
“So, when the hemlocks finally die from an HWA infestation, the invertebrates can now not thrive there, and we see a lower in freshwater fish populations. This, after all, causes much more points going up the meals chain, in order that one tiny insect is affecting a whole ecosystem.”
Automobiles, horses or the rest that comes into contact with infested branches can choose up the adelgids and transfer them to new areas. To attempt to forestall that, Land & Backyard Protect workers have been pruning again hemlock branches that have been hanging over carriage roads.
Bushell recommends that folks preserve a detailed eye on the hemlocks on their property for indicators HWA, particularly if new bushes have been trucked in from factors south.
However are monitoring and prevention efforts simply delaying the inevitable?
All the way in which again in 2010, scientists with the Rocky Mountain Local weather Group and the Pure Sources Protection Council wrote a 42-page report titled “Acadia Nationwide Park in Peril: The Threats of Local weather Disruption.”
“Hotter winters…are selling the unfold of a tree-killing insect from Asia, the hemlock wooly adelgid, believed to be on its strategy to remove japanese hemlocks from the Northeast,” they wrote.
“The lack of the hemlocks from international warming’s mixed results on habitat availability and HWA infestation threatens to destroy your entire ecosystem, resulting in an irreversible lack of North American biodiversity.”
The Maine Forest Service web site has details about figuring out invasive species together with HWA and what to do should you discover them.
Dick Broom covers the cities of Mount Desert and Southwest Harbor, Mount Desert Island Excessive College and the college system board and superintendent’s workplace. He enjoys mountain climbing together with his golden retriever and discovering new locations for her to swim. [email protected]
