In the upper reaches of some of the largest trees in Nova Scotia, a tiny black speck the size of a sugar crystal is causing significant damage. The hemlock woolly adelgid, an invasive insect discovered in the province in 2017, is swiftly spreading through Nova Scotia’s hemlock forests, resulting in eerie, ghost-like trees in its path. By extracting sap from the base of hemlock needles, the adelgid can fatally harm a tree within a decade, leaving behind a white wool-like substance that characterizes them.
Researchers at Acadia University are actively exploring solutions to combat this threat. Led by Acadia, a research initiative is examining the efficacy of insecticidal treatments in managing the hemlock woolly adelgid infestation. Additionally, they are establishing a biological control facility to regulate adelgid populations.
Kirk Hillier, a biology professor at Acadia University and the project’s lead researcher, emphasized the pressing nature of the situation, having witnessed the impact of dead hemlocks firsthand. The project focuses on two key aspects: assessing the impact of adelgid infestation on biodiversity and studying the effects of insecticides on hemlocks.
Hemlocks are currently treated with two types of insecticides, either injected into the tree or sprayed on the bark to safeguard their survival. Despite potential concerns about the impact of insecticides on pollinators, the necessity of protecting hemlocks outweighs these considerations in Nova Scotia.
To evaluate the situation, researchers will monitor insects and birds to determine any biodiversity alterations resulting from infested trees, as well as assess the risks posed by insecticides to various wildlife. Acadia researchers are also conducting laboratory experiments to evaluate the effect of insecticides on ground-nesting bees.
One of the challenges with insecticides is their cost and time-intensive application process. In an effort to streamline treatment efforts, the project is testing specialized traps to detect adelgid presence early on, using molecular tools for enhanced detection accuracy.
The long-term strategy involves the detection of hemlock predators, crucial for hemlock preservation. Acadia researchers are expanding these efforts by utilizing a campus greenhouse as a rearing and testing facility for biocontrol measures, intending to release various insect species to manage the adelgid without relying on insecticides.
Donna Crossland, a forest ecologist involved in hemlock protection measures, stressed the importance of considering both short and long-term approaches to combat the hemlock woolly adelgid. While initially hesitant about using insecticides, she acknowledges their necessity until biocontrol methods can be fully implemented.
The urgency of the situation has prompted researchers to advocate for public awareness and secure operational funding for a sustainable biocontrol program. Delaying the establishment of such a program could result in irreversible tree losses, underscoring the critical need for immediate action to safeguard Nova Scotia’s hemlocks.
