AN UPDATE ON TREATMENT FOR THE HEMLOCK WOOLLY ADELGID AT CLEAR CREEK METRO PARK
Staff and volunteers were able to tag over 6,000 hemlock trees in two separate areas of Clear Creek Metro Park this past spring. Both stands had evidence of infestation by Hemlock Woolly Adelgid (HWA) and will be the priority treatment areas.
Teams went into the hemlock stands and measured each hemlock and gave it a unique code to tag the tree. The tree’s diameter at breast height, or DBH, was taken and recorded. This measurement will determine how much chemical the tree will be receiving. Other factors, including distance to water and ground conditions will help determine the type of chemical treatment to use.
Two different treatment methods will be used. One is the injection method. Syringes with a calculated amount of chemical is inserted around the base of the tree. The chemical is slowly injected into the tree where it will be distributed into the canopy by the tree’s circulation.
The second method is soil application, where the chemical is sprayed into the soil around the base of the tree and the roots will take it up. Both methods distribute the pesticide throughout the tree. Adelgids will ingest the pesticide when they are feeding on the hemlock. Treatments can last up to five years, giving the tree protection from the future infestations.
In the coming months, staff and volunteers will treat as many trees as possible. We will also continue to monitor for the occurrence of HWA in the winter months and adjust our treatment efforts as well.