As the snow of winter fades away in Nova Scotia, researchers at Dalhousie University are urging the public to be on the lookout for abandoned paper wasp nests. These nests are being gathered from various locations across the province to investigate potential heavy metal contamination.
Carlie Ashton, an undergraduate student in environmental science at Dal’s agricultural campus in Bible Hill, Nova Scotia, is leading this research as part of her honours project. She is focusing on two species of wasps, aerial yellowjackets, and bald-faced hornets, which construct their nests by gathering wood or plant fibers from their surroundings. By chewing and regurgitating this material, they create a pulp used to build the nest structure.
The study aims to compare the levels of copper and chromium, common wood preservatives, in wasp nests from urban and rural areas. Ashton anticipates that nests in urban settings may exhibit higher contamination levels due to the presence of wood treated with these chemicals, unlike nests in rural environments, where the wasps likely use natural sources like trees.
Individuals who come across abandoned wasp nests are encouraged to contact Ashton to contribute to the research. During this time of year, the nests are deserted as the wasps perish in the cold, while the mated queens seek shelter under tree bark or in various natural hiding spots.
Despite the wear and tear on the nests from winter conditions, Ashton will dry them in a microwave, dissolve the material, and analyze it for heavy metal content using specialized equipment. This type of investigation has been done on other species elsewhere, but not specifically on these species in Canada, as Ashton pointed out.
The research project seeks to determine if aerial yellowjackets and bald-faced hornets can serve as indicators of heavy metal presence. Assistant professor Paul Manning, one of Ashton’s project supervisors, highlighted the importance of understanding the pressures insects face due to various stressors like climate change, habitat loss, and pesticides.
While the study does not focus on the effects of contamination on the wasps, previous research suggests that copper exposure can impact their lifespan and reproductive capabilities. Manning emphasized the need to comprehend the challenges insects encounter in today’s changing environment.