Researchers Seek Abandoned Wasp Nests in Nova Scotia for Heavy Metal Study

As winter’s snow begins to recede in Nova Scotia, researchers from Dalhousie University are urging residents to report any abandoned paper wasp nests they encounter. The team, led by undergraduate student Carlie Ashton, aims to collect these nests across the province for a study investigating potential heavy metal contamination.

Ashton, who is conducting this research as part of her honours project at Dal’s agricultural campus in Bible Hill, has focused on two species: aerial yellowjackets and bald-faced hornets. These wasps construct their nests using wood and plant fibers sourced from their environment. By chewing the material and regurgitating it, they create a pulp that forms the nest.

The research hypothesizes that nests located in urban areas may exhibit higher levels of copper and chromium, common wood preservatives. Ashton explained, “If the wasp is in an urban area, they might be chewing on something like a deck, which is more likely to have wood preservatives, compared to a wasp in a rural area, which might be chewing on more natural sources like trees.”

Residents are encouraged to contact Ashton if they find a nest, as this time of year typically sees wasps die off due to cold temperatures, leaving behind their nests. The mated queens often seek shelter under tree bark or in logs and leaf litter. Nests can be found in various locations, including barns and sheds. Ashton aims to gather all specimens by May, which marks the beginning of the wasp nesting season.

Despite potential weather-related damage to the nests, Ashton stated that this will not hinder her research. She plans to dry the nests in a microwave, then dissolve the material for analysis. The study will utilize advanced machinery to detect heavy metal concentrations.

While similar research has been conducted on various species, Ashton noted that this specific study on aerial yellowjackets and bald-faced hornets is unprecedented in Canada. Not all insect species can serve as reliable biological indicators of heavy metal presence, making this research particularly valuable.

One of Ashton’s supervisors, Paul Manning, an assistant professor, commented on the significance of understanding contaminant levels. “We’re living in a time where we’re seeing insect populations declining around the world as a combination of different stresses from heat stress to habitat loss to pesticides,” he said. Manning emphasized that knowing the presence and quantities of contaminants can provide insights into the pressures faced by these insects.

Although the primary goal is not to study the effects of contamination on wasps directly, previous research has indicated that copper exposure can diminish their lifespan and affect reproductive capabilities. The findings from this study could contribute to a broader understanding of environmental impacts on insect populations.

As the researchers embark on this project, they hope to shed light on the health of local ecosystems and the potential threats posed by human activities. Anyone who encounters a wasp nest is encouraged to participate in this important research, helping to improve our understanding of environmental contamination in Nova Scotia.