As the snow of winter fades 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 in the province to investigate potential heavy metal contamination.
Carlie Ashton, an undergraduate student in environmental science at Dal’s agricultural campus in Bible Hill, N.S., is leading the study as part of her honours project. She is focusing on two specific species, aerial yellowjackets and bald-faced hornets, which construct their nests by gathering wood or plant fibers from their surroundings. These materials are chewed and regurgitated by the insects to create the nest structure.
The research is expected to reveal that wasp nests in urban settings are more likely to be contaminated with copper and chromium, common wood preservatives, compared to nests found in rural areas. Ashton explained that urban wasps may be exposed to wood preservatives from sources like decks, while rural wasps might use more natural materials like trees.
Anyone who discovers a nest is encouraged to reach out to Ashton to contribute to the study. During this time of year, nests are left empty as the wasps perish due to cold temperatures, with mated queens seeking shelter elsewhere, such as under tree bark or in various natural hiding spots.
Ashton aims to collect all specimens by May before the wasps start building new nests. Despite the nests being weathered after winter, Ashton emphasized that their condition does not affect the research. The nests will be dried, processed, and analyzed for heavy metal content using specialized equipment.
This kind of research has not been conducted on these specific species in Canada before, according to Ashton. By determining the presence and levels of contaminants, the study will shed light on the environmental pressures faced by aerial yellowjackets and bald-faced hornets.
Assistant professor Paul Manning, one of Ashton’s project supervisors, highlighted the importance of understanding the challenges insects are encountering in the current environment. While the research does not focus on the effects of contamination on the wasps, previous studies have suggested that copper exposure could impact the lifespan of the insects and their reproductive capabilities.
Overall, this study aims to contribute valuable insights into the potential impacts of heavy metal contamination on wasp populations and their ecological roles.