Hemlock Woolly Adelgid (HWA) is an invasive forest pest that has been detected at several conservation areas. While not harmful to humans or pets, it is destructive to eastern hemlock trees.
HWA feeding removes plant fluids and causes needle drop, twig dieback, and eventually tree mortality, sometimes in as little as four years. So, early detection is critical to help protect these trees and prevent spreading to other conservation areas. You can look for:
- Cottony, white egg sacs at the base of tree needles resembling cotton balls or clumps of snow (These are tiny! Only about 3-6 millimeters in size!);
- Swelling at the twig tips;
- Twig dieback; and
- Grey foliage.
It can be spread by wind, animals, and human movement of nursery stick, logs, firewood, and other wood products. So, to help prevent the spread of HWA, visitors are asked to do the following:
- Know the signs of an HWA infestation;
- Report suspected HWA or HWA damage on EDDMapS (https://www.eddmaps.org/) or to kroyer@npca.ca if seen at a conservation area;
- Use a lint roller to remove potential crawlers from clothing and beating and/or lint roll hats and coats worn in an affected area;
- Brush off footwear worn;
- Wipe down all equipment with an ethanol-based cleaner;
- Wash all clothing worn before entering another conservation area or woodlot; and
- Stay on the trails and keep dogs on a leash.
To further prevent the spread of this pesky bug, please do not remove any natural material from the conservation area. Instead, leave nature where it is for all to enjoy.
NPCA is working with the Canada Food Inspection Agency to determine best containment and control practices and is following all their recommendations. Aswell, this ongoing situation is being monitored by NPCA’s internal Invasive Species Working Group who continue to ensure the community remains informed.
More information about the bug can be found on the Invasive Species Centre website.
Frequently asked questions about HWA are answered on the Canada Food Inspection Agency website here.