Part 2

Unfortunately several insects attack Hemlocks. The woolly adelgid (the worst) is a non native insect that feeds on hemlock twigs and creates a loss of tree needles (it can also be found on Norfolk Island pines – so beware of white “snowy” patches on these or other live trees that are sold as indoor Christmas trees). This insect reduces the ability of the tree to produce new growth, and an untreated infestation can kill a tree in 2 – 12 years. Unfortunately this pest has reached Maine’s coastal areas and is spreading inland.

Over one third of the Eastern hemlock’s native range has been infested with this bug. The larvae spread rapidly through the air on their own or by wind and birds. Even though a quarantine has been established for Maine, New Hampshire and Vermont, the infestation is spreading. The 2013 revision of the quarantine rule is one reason why:

“Hemlock chips with top material, and uncomposted bark with top material from quarantined areas may be imported into non-quarantined areas in the State of Maine provided that said material is shipped only to sites within Maine that are preapproved by the Maine Forest Service, Department of Agriculture, Conservation & Forestry. Such sites must have a compliance agreement with the Maine Forest Service”.

What?

Here is the kind of legal crazymaking loophole that catches my hair on fire. If you use bark as mulch, which many gardeners do you are probably responsible for the spread of this devastating disease.

In the northern portion of the Hemlock’s range, the color of the Hemlocks infested by this invasive insect will typically change from a healthy, dark green to a sickly, grayish-green color after just a few years, and death typically occurs four to ten years after an initial infestation.  Any trees that do manage to survive the direct effects of this assault are usually weakened to the point where they may die from secondary causes.

Hemlock scale and Hemlock borers are additional threats. Brown flecks on the needles reveal the presence of the scale. Should you note a collection of orange chips surrounding a Hemlock tree (due to woodpeckers drilling into the cambium for insects) then the Hemlock has probably been infested by the borers.

Once the insects are established on Hemlocks there is little to be done. The Maine Forest service has released a couple of non native insects from Japan to deal with infestations, creating of course, another problem in its wake.

With the future of these trees so uncertain I take refuge in the present and spend a lot of time appreciating these beautiful woodland trees. One day, they may not be around to enjoy.

 

 

 

 

 

 

 

 

 

 

 

 

 

 

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