Researchers at Dalhousie University are urging the public to be on the lookout for abandoned paper wasp nests as winter retreats in Nova Scotia. The purpose is to examine these nests from various locations in the province for potential heavy metal contamination.
Carlie Ashton, an environmental science undergraduate student at Dal’s agricultural campus in Bible Hill, N.S., is spearheading this study as part of her honours project. She is particularly interested in two species of wasps, aerial yellowjackets, and bald-faced hornets, which construct their nests by gathering wood or plant fibers from their surroundings.
Ashton anticipates that nests in urban settings may exhibit higher levels of copper and chromium, common wood preservatives, compared to nests in rural areas. She explains that wasps in urban areas might be exposed to wood preservatives from structures like decks, while those in rural areas may rely on natural sources like trees for nest construction.
Individuals who come across abandoned wasp nests are encouraged to reach out to Ashton to contribute to the research. With the wasps perishing due to cold temperatures at this time of year, the mated queens seek shelter in locations such as under tree bark or in woodpiles, logs, or leaf litter.
Ashton aims to gather all specimens by May when the wasps commence building new nests. Despite the wear and tear on the nests over winter, Ashton will use a microwave to dry them before analyzing the material for heavy metals using specialized equipment.
This study by Ashton fills a gap as similar research has not been conducted on these specific wasp species in Canada. By investigating the presence and levels of contaminants, researchers can better comprehend the challenges faced by these insects amidst global declines in insect populations due to various factors like habitat loss and pesticides.
While the study does not focus on the effects of contamination on the wasps, previous research indicates that copper exposure can impact the lifespan of wasps and reproductive capabilities. Assistant professor Paul Manning, one of Ashton’s supervisors, emphasizes the importance of understanding the pressures on insects in the current environment.
The study sheds light on the potential impacts of heavy metal contamination on aerial yellowjackets and bald-faced hornets, offering insights into their resilience and survival in changing ecosystems.
