July 23, 2025
This article was originally published in the August 2025 edition of The Grower.
Wireworms are a notorious pest in BC that pose a big risk to our corn, potato and cereal crops, industries that are worth multimillions annually. With its warm summers and soil, combined with changing growing practices and ineffective insecticides, the province has inadvertently cultivated favourable conditions for the wireworm.
Of the approximately 200 species in BC, only about 10 are pests. The others are harmless, or even beneficial to BC ecosystems.
Smooth criminals
Despite their name and appearance, wireworms aren’t worms. They are insects; the larval stage of click beetles. Mature click beetles aren’t an issue but as larvae, they feed on roots, seeds, stems and tubers. This behaviour results in crop loss at multiple levels, from wireworms snacking on seeds before they can grow, to harvested produce being severely damaged and filled with holes created by tunneling wireworms.
There are a few common ways to address a wireworm problem. Insecticides are the most popular way to manage them, but they come with environmental drawbacks. Pheromone traps and soil baits can help to determine if wireworms exist in a field. These are not always reliable, however, because the pests can be notoriously hard to identify.
Spotting the difference
There are a few factors that help wireworms remain hidden. Firstly, they are tough creatures. Wireworms live in the soil for several years and can go for long periods without food. In thriving populations, multiple generations live in the same field together.
Multiple species are also found together in fields, with some causing more damage than others, so mistakes can be made in any catch-all containment method. Identifying a pest species takes a lot of time and expertise that many people do not have.
Genomics unearths a solution
Dr. Michelle Franklin from Agriculture and Agri-Food Canada (AAFC) and Dr. Richard Hamelin from the University of British Columbia (UBC) Department of Forest & Conservation Sciences are leading a project to quickly and effectively determine if an insect is one of the top five species of wireworm that pose the greatest threat to BC growers.
The researchers are developing DNA detection tools to determine if pest wireworms are in a field prior to planting. Their work involves collecting samples of the five most common pest wireworms, sequencing their genomes, and combining these results with the understanding of the different physical traits to develop a “database” with genetic information for each unique species.
These databases contain DNA sequences of genes, such as cytochrome c oxidase subunit I (COI), that serve as barcode libraries to help identify different animal species. COI barcode libraries for wireworms already exist and have proven to be useful for identification in other parts of the world. The researchers also want to develop field-ready tests that use portable DNA extraction methods.
Ultimately, a soil test can reveal if a field is at risk and inform growers whether pesticides will be needed as a preventative measure. Confirming what’s in a field can help BC growers make quicker, more targeted decisions, save money and avoid environmental contamination.
The researchers also see this as a first step in helping growers across Canada understand if pesticides are necessary based on their situations. This is just the beginning of the potential BC researchers have to offer in addressing the nationwide wireworm problem in a safe, sustainable way.
