“Dalhousie University Seeks Help Locating Metal-Contaminated Wasp Nests”

With the melting of winter’s snow in Nova Scotia, researchers at Dalhousie University are seeking assistance from the public to locate abandoned paper wasp nests. The purpose of this initiative is to investigate potential heavy metal contamination within these nests.

Carlie Ashton, an environmental science undergraduate student at Dal’s agricultural campus in Bible Hill, N.S., is spearheading this research as part of her honours project. She is particularly interested in studying two species of wasps, aerial yellowjackets, and bald-faced hornets, which construct their nests by gathering wood or plant fibers from their surroundings. The insects process the collected material by chewing it into a pulp, which they then use to build their nests.

Ashton anticipates that nests located in urban areas will exhibit higher levels of copper and chromium contamination, commonly found in wood preservatives, compared to nests in rural settings.

Explaining further, Ashton mentioned that wasps in urban areas might utilize materials with wood preservatives like decks, which are potential sources of heavy metals, while those in rural areas are more likely to gather from natural sources such as trees.

If anyone discovers an abandoned wasp nest, they are encouraged to contact Ashton to contribute to the study. During this time of the year, nests are vacated as the wasps perish due to the cold weather, while the mated queens seek shelter under tree bark or in various locations like logs, woodpiles, or leaf litter.

Typical locations where nests may be found include barns, sheds, or trees. Ashton aims to gather all specimens by May, as this marks the period when wasps start constructing new nests.

Despite potential wear and tear on the nests from winter conditions, Ashton emphasized that the condition of the nests does not affect the research. She plans to dry the nests in a microwave, dissolve the material, and analyze it for heavy metal content using specialized equipment.

Ashton highlighted that while similar research has been conducted on other species elsewhere, such investigations have not been carried out on aerial yellowjackets and bald-faced hornets in Canada to her knowledge. The study aims to determine if these species can serve as indicators of heavy metal presence.

Assistant professor Paul Manning, one of Ashton’s project supervisors, emphasized the importance of understanding the presence and levels of contaminants to comprehend the challenges faced by these insects. He pointed out that insect populations worldwide are declining due to various factors like heat stress, habitat loss, and pesticide use, making survival increasingly challenging.

While the primary focus is not on assessing the impact of contamination on the wasps, Manning noted that previous research suggests copper contamination could reduce the lifespan of the wasps and affect the reproductive capabilities of males and the queen’s egg-laying capacity.

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