Help! Why Can’t I find Hemlock?

If you have been looking for hemlock, chances are that you have not been able to find them. But why this? Read on to find out!

Once hemlocks covered the east coast, but now they are few and far between. Sure, you can find spots where they do still grow in the wild, but not compared to what they once were. Why is this? A small insect called Hemlock Wooly Adelgid.

Here are 8 things to know about Hemlock Wooly Adelgid:

1. 1. Hemlock Wooly Adelgid is closely related to aphids:

      Hemlock Wolly Adelgid is closely related to aphids and does damage in much the same way. They both do damage by feeding on the plants in sucking out the sap.

   2. Hemlock Woolly Adelgid is easy identified by their egg cases:

      Egg cases are the easiest way for Hemlock Woolly Adelgid to be identified. These eggs look much like small pieces of cotton and occur on the needles and stems of the branches.

   3. Eastern Hemlock is not resistant to Hemlock Woolly Adelgid:

      Unfortunately, the most common variety of Hemlock on the East Coast, the Eastern Hemlock is not resistant to the Hemlock Woolly Adelgid. And unfortunately, neither is the Carolina hemlock, also found on the East Coast.

   4. Hemlock Wooly Adelgid more than likely came from Japan:

      Hemlock Woolly Adelgids were first noted in 1951 in Virginia. More than likely they originated from Japan coming with shipments of ornamental Hemlock shipments from Japan. It is worth noting, however, that Hemlock Woolly Adelgid does live on the West Coast and are thought to have been there for thousands of years. For this reason, Western Hemlocks have had time to become resistant to Hemlock Woolly Adelgid.
      Hemlock Wooly Adelgid was first found in Pennsylvania in the late 1960s. And unfortunately today it is found most places east of the Appalachian Mountains. The unfortunate thing is that is killing much of the hemlocks throughout the Appalachian Mountains as well. But if there is a bright side, it is that west of the mountains has tended to avoid infestation.

   5. Hemlock Wooly Adelgid is easily controlled by using pesticides:

      Although Hemlock Woolly Adelgid is a big problem, they are easily controlled by pesticides. The best time to apply pesticides is from late September to October. This will kill the females preparing to over winter.

   6. Hemlock Wooly Adelgid has no natural predators in the US:

      The unfortunate thing is that Hemlock Woolly Adelgid has no predators native to the United States. There are efforts to introduce predatory insects from Japan but this is an ongoing project and they are not readily available quite yet.

   7. The main reason why plants die are secondary causes (Or at least is quickened):

      Although the damage is not generally enough to kill the plant on its own, it is generally enough that the secondary causes will kill the plant or at very least kill it faster. Mortality generally happens within 4-10 years.

   8. Hemlock Woolly Adelgid is mainly an issue on wild plants:

      Hemlock Woolly Adelgid is not a big issue on cultivated plants. The reason for this is that pesticides easily control them. It is, however, a big issue on the wild trees as they do not have intensive care as in cultivated settings. But in spite of this, many nurseries are reluctant to sell hemlocks and many customers in the know are unwilling to buy or deal with the hassle.

Do you have Hemlock? Have you had trouble with Hemlock Wolly Adelgid? Have you wondered why you can’t find Hemlock? Comment below.

Further reading:

https://ag.umass.edu/landscape/fact-sheets/hemlock-woolly-adelgid
https://ento.psu.edu/extension/factsheets/hemlock-woolly-adelgid
https://www.nrs.fs.fed.us/disturbance/invasive_species/hwa/
https://extension.psu.edu/hemlock-woolly-adelgid-hwa
https://www.dec.ny.gov/animals/7250.html