Friday, December 2, 2011

Hemlock Wooly Adlegid

The  Hemlock Wooly Adelgid (HWA) is a forest pest that attacks pine trees, specifically Eastern Hemlocks. It is an invasive species from Asia brought over to America around 1922, it was found in PA records around 1967. It is a problem in the US, because it sucks juices from the base of Hemlock needles. This prevents the tree from photosynthesizing and kills it. There are also no native predators in the US, which causes them to just keep breeding and spreading. There are two main tactics that local naturalists are using to remove them. One is a chemical approach which when applied to the Hemlock trees, kills the Wooly Adlegid. The other technique is to use a biological control. This would consist of us introducting one of it's natural predators, a type of beetle.  Beetles are currently being introduced into Pennsulvania to control HWA using beetles from the Pacific Northwest.  There are benefits and drawbacks of using the chemical and the beetles for biological control.
This is Thad our Park Ranger giving us a lesson on Hemlock threes and more importantly the Hemlock Wooly Adlegid.


In our last Creekers meeting we met with April and Thad to help them measure and tag Hemlocks. We were educated about the HWA and then split into two groups so we could cover more ground. In that one hike we collect data from 113 different Hemlocks. This information will give us a more accurate number of Hemlocks and help estimate a price for a chemical treatment.

Andrew House; a Creeker participating in data collecting got himself into a web of troubles while trying to measure the circumference of a Hemlock.