As the snow of winter dissipates in Nova Scotia, researchers at Dalhousie University are urging the public to be on the lookout for abandoned paper wasp nests. The nests are being gathered from various locations across the province to investigate potential contamination by heavy metals.
Carlie Ashton, an undergraduate student in environmental science at Dal’s agricultural campus in Bible Hill, N.S., is undertaking this study as part of her honours project. She is focusing on two species, aerial yellowjackets and bald-faced hornets, which construct their nests by gathering wood or plant fibers from the environment. These materials are chewed by the insects to create a pulp that forms the nest.
The research anticipates that nests in urban areas will likely show higher levels of copper and chromium contamination, common wood preservatives, compared to nests in rural settings. Ashton explains that urban wasps may use materials like deck wood, containing wood preservatives, while rural wasps may rely on natural sources like trees.
Individuals who come across abandoned nests are encouraged to contact Ashton to contribute to the study. During this time of year, nests are vacated as the cold temperatures lead to the demise of the wasps, with mated queens seeking shelter elsewhere, such as under tree bark or in various natural structures.
By May, Ashton aims to collect all specimens, even though the winter may have taken a toll on the nests’ condition. The nests will be dried, and the material dissolved for analysis of heavy metal content using specialized equipment.
This research, focusing on aerial yellowjackets and bald-faced hornets, is a unique endeavor in Canada, according to Ashton. The study aims to determine if these species can serve as indicators of heavy metal presence, providing insights into the environmental pressures faced by these insects.
Assistant professor Paul Manning, one of Ashton’s project supervisors, emphasizes that understanding the presence and levels of contaminants is crucial for comprehending the challenges insects encounter in today’s world. While the study does not delve into the effects of contamination on the wasps, previous research suggests that copper exposure can impact their lifespan and reproductive capabilities.
The investigation sheds light on the broader context of declining insect populations globally, attributed to factors such as habitat loss, pesticides, and climate change. Manning underscores the importance of recognizing these combined stresses on insects, affecting their survival.
As the project progresses, the findings could contribute valuable knowledge to conservation efforts and environmental management strategies.