Hemlock Woolly Adelgid
Hemlock Woolly Adelgid (HWA) is an invasive aphid-like insect that attacks and kills hemlock trees, and poses a serious threat to our Eastern hemlock forest ecosystems. Eastern Hemlock are what is known as a foundational species, contributing to whole ecosystems by effecting environmental conditions. The big canopies provide shade and controlled temperature conditions in the understory, slow transpiration rates (compared to hardwoods) contribute to more water availability in the rest of the ecosystem, and the slow decomposing of needles affect nutrient cycling processes. All of these processes are involved in supporting unique fungi and insects in these habitats. Hemlocks are a substantial species in the old-growth forests in Mi'kma'ki / Nova Scotia; a majority of the old-growth forests that are left are comprised of Eastern Hemlocks.
HWA is defoliating hemlocks. The trees die within 4-15 years of HWA presence. The death of the hemlocks thus effects the full ecosystem that the live trees support.
Our work at MTRI focuses on sharing information on this invasive species with the public, working with government to monitor its spread, and assist with Nova Scotia’s management plan. In the attached pages you can find information on identification tips, how to slow the spread, and how to report HWA.
To learn more about the fight against HWA you can visit the Nova Scotia Hemlock Initiative website.
