As the snow of winter in Nova Scotia starts to melt away, researchers at Dalhousie University are urging the public to be on the lookout for abandoned paper wasp nests. The researchers aim to gather these nests from various locations across the province to analyze them for potential heavy metal contamination.
Carlie Ashton, an undergraduate student majoring in environmental science at Dal’s agricultural campus in Bible Hill, N.S., is spearheading the 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, chewing the material, and regurgitating it to build the nest.
It is anticipated that nests found in urban areas may exhibit higher levels of copper and chromium, common wood preservatives, compared to nests in rural settings. Ashton explained that wasps in urban regions might source their materials from items like decks containing wood preservatives, potentially leading to increased heavy metal content in the nests.
Individuals who come across abandoned wasp nests are encouraged to reach out to Ashton to contribute to the research. With the arrival of spring, the nests are deserted as the wasps perish due to the cold weather, while mated queens seek shelter in places like under tree bark, logs, woodpiles, or leaf litter.
Despite potential wear and tear on the nests after winter, Ashton emphasized that the condition does not affect the research. The nests will undergo a drying process in a microwave, followed by material dissolution and analysis for heavy metals using specialized equipment.
This type of research has been conducted on other species elsewhere but has not been explored for these specific wasp species in Canada to Ashton’s knowledge. By investigating whether aerial yellowjackets and bald-faced hornets can serve as indicators of heavy metal presence, the project aims to shed light on the environmental pressures faced by these insects.
Assistant Professor Paul Manning, one of Ashton’s project supervisors, highlighted that understanding the presence and levels of contaminants is crucial for comprehending the challenges insects encounter in today’s environment. While the study does not focus on the effects of contamination on the wasps directly, previous research has suggested that copper exposure can impact the lifespan of wasps and affect their reproductive capabilities.
The research aims to contribute to the broader understanding of insect populations facing various stressors, including habitat loss, climate change, and pesticide use, which collectively threaten their survival.