As the winter snow in Nova Scotia begins to melt, researchers at Dalhousie University are urging the public to watch out for abandoned paper wasp nests. These nests are being gathered from various locations across the province to investigate possible heavy metal contamination.
Carlie Ashton, an environmental science undergraduate student at Dal’s agricultural campus in Bible Hill, N.S., is leading the research for her honours project. She is particularly focused on two species, aerial yellowjackets, and bald-faced hornets, which construct their nests by collecting wood or plant fibers from their surroundings. The insects chew and regurgitate the material to create 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 are more likely to be contaminated due to the presence of wood treated with these heavy metals.
Anyone encountering an abandoned nest is encouraged to contact Ashton to contribute to the study. During this time of year, the nests are vacated as the wasps perish in the cold, while the mated queens seek shelter under tree bark or in various natural hiding spots.
Although the nests may be weathered from winter conditions, Ashton plans to analyze them for heavy metals by drying them in a microwave and using specialized equipment for testing. This type of research has not been conducted on these species in Canada previously, making this study particularly significant.
Assistant professor Paul Manning, one of Ashton’s project supervisors, highlighted the importance of understanding the environmental pressures insects face. He emphasized that declining insect populations worldwide are influenced by various factors such as habitat loss, pesticides, and climate change.
While the study does not focus on the direct effects of contamination on the wasps, previous research suggests that exposure to copper can impact their lifespan and reproductive capabilities. Manning stressed the need to comprehend the presence and quantity of contaminants to gain insight into the challenges insects encounter.
The research project aims to determine if aerial yellowjackets and bald-faced hornets can serve as indicators of heavy metal pollution. By investigating the levels of contamination in their nests, researchers hope to shed light on the broader ecological issues affecting these insect species.