Researchers at Dalhousie University in Nova Scotia are urging the public to be on the lookout for abandoned paper wasp nests as the winter snow begins to melt. The nests are being collected across the province to investigate potential heavy metal contamination.
Carlie Ashton, an environmental science student at Dal’s agricultural campus, is leading the research for 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.
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 locations may show higher contamination levels due to the presence of wood preservatives from structures like decks.
Individuals who come across abandoned wasp nests are encouraged to contact Ashton to contribute to the study. With the wasps deceased during this time of year, the mated queens are likely seeking shelter in various locations such as tree bark or woodpiles.
While the nests may show signs of wear after winter, Ashton will dry and analyze them for heavy metals using specialized equipment. This research, focusing on aerial yellowjackets and bald-faced hornets, is unique in Canada and aims to determine if these species can serve as indicators of heavy metal pollution.
Assistant professor Paul Manning, one of Ashton’s supervisors, highlighted the importance of understanding the environmental pressures faced by insects. The presence of contaminants can give insights into the challenges insects encounter, especially amidst declining populations worldwide due to various stressors.
Although the study does not investigate the direct impact of contamination on the wasps, previous research suggests that heavy metals like copper can affect their lifespan and reproductive capabilities. This ongoing project sheds light on the ecological implications of heavy metal exposure on insect populations.