Hemlock Woolly Adelgid

These nasty little buggers will suck the life out of your Hemlock trees. Literally.
The hemlock woolly adelgid (HWA) is a small aphid-like insect that can kill a mature hemlock in as few as three years by sucking the sap from the tender hemlock shoots. Originally introduced from Asia, HWA first appeared in New Hampshire forests in 2000, and Maine in 2003.

Treatment options differ based on the number of trees, location and the severity of infestations.
  • Foliar applications such as horticultural oils and insecticidal soaps are effective when the entire tree can be sprayed and saturated, ensuring the insecticide comes in contact with the adelgid. This method needs to be done at the proper times during the HWA life cycle.
  • Soil applications with a systemic insecticide may be a better option for larger trees. Soil injection allows for optimal placement of the insecticide, which is taken up by the root system of the tree and moves throughout the tree. Multi-year coverage can be achieved.
  • Trunk applications -- products are sprayed on the trunk of the tree and absorbed through the bark and moved throughout the tree. This will virtually eliminate the need for putting pesticides into the ground and doing trunk injections. Multi-year coverage can be achieved.
  • Trunk injections are another option to deliver systemic insecticide. Trunk injections can cause extensive tree wounding and tree stress, but may be the only option in environmentally sensitive areas.
“The tree crew was a joy to watch in action. They were efficient, professional, and courteous.”
Richard, Hampton, NH