A confirmed infestation of Hemlock Woolly Adelgid (HWA) has made its way the Halifax region for the first time — an insect that is deadly to hemlock trees.
“Hemlock Woolly Adelgid, or HWA, it’s an invasive species,” said Ron Neville of the Canadian Food Inspection Agency (CFIA).
“It basically attacks trees at the base of their needles and it feeds on the cells that are really important for those needles to survive.”
When tens of thousands of these insects infest the same tree, the tree starts to decline and eventually die.
“My group is working on surveillance, we’re trying to find new detections early,” Neville said. “We’re also trying to slow its spread by putting in regulations to try and prevent people from moving HWA long distances, before it has a chance to spread naturally.”
A CFIA area survey biologist, Neville is part of a team testing hemlock trees for infestation in the HRM area after a case was confirmed on a residential property in Bedford, N.S.
“You can spread HWA very quickly by moving something like firewood or moving a young plant from an infested area into a new area.”
Many eastern hemlocks are hundreds of years old and make up much of the remaining old growth in Nova Scotia.
The province’s department of environment is now working with partners, including the Mi’kmaw who believe hemlock have spiritual significance, to identify which hemlock stands should be prioritized.
“We’re doing what we can with the money that we have and really working day and night to protect, you know, the best of the best hemlock in these conserved areas,” said N.S. Department of Environment Protected Ares Coordinator Sally Steele.
The province is leading efforts that are currently underway to administer insecticides to protect hemlock trees for five to seven years at a time against HWA.
To help with early detection and treatment efforts, Neville is asking the public to report sightings of the white woolly egg sacs to the CFIA.
“Already, there’s been heavy impacts in Digby and Shelbourne Counties and also now in Lunenburg County,” said Steele. “Now that it’s been detected in Bedford, we know that it’s continuing to move rapidly eastward and there’s a lot that we are going to lose.”
In Southwestern Nova Scotia, the impacts of HWA on hemlock trees has been devastating — most of the tree species in that are are dead with no regeneration happening.
The once cool and dark canopies of space for other animals to build their homes in is now very open and exposed.
“If it does arrive here, when it arrives here, we want to try to find it as early as possible so that the city and the folks that look after this park have as much time as they can to try to manage it before these trees die,” said Neville.
While putting infested trees on life support through insecticides in the only short-term solution available at the moment, Steele says long-term solutions are being worked on.