GrainsWest Spring 2020

Spring 2020 grainswest.com 11 BY IAN DOIG Haley Catton displays the larval and adult forms of the three most common wireworm species her project has identified in southern Alberta. From left to right, they are Hypnoidus bicolor , Selatosomus aeripennis destructor (common called prairie grain wireworm) and Aeolus mellillus . Photo:Courtesyof HaleyCatton for having an infestation,” said Catton. Farmers will be able to better judge when the use of chemical control will be most effective and when it will not. “If we can predict where the problem’s going to be, we can keep an extra eye on those fields to see if they need control,” said Catton. As well, in determining methods to interrupt the mating cycle of adult click beetles, the insects may lay fewer eggs. This would result in fewer wireworms in the soil. Catton emphasized that the project was not a field survey, but involved intensive weekly sampling during the growing season, using worm traps and soil cores. While counting and identifying wire- worms, her team is doing the same for beneficial insects such as ground beetles with the aim of similarly determining how they’re affected by crop rotation. Each insect collected in 2019 is now being laboriously identified under a mi- croscope. The research team will identify patterns that emerge from the data, and results will be published within two years. The non-chemical emphasis of the study addresses the inherent drawbacks of chemical control, such as cost, the development of insecticide resistance and environmental impacts. Catton said it’s a positive development that new wireworm chemicals are coming out, but with inte- grated control strategies, farmers can use them more effectively. With neonics merely impeding wire- worm activity, there has been incentive to make new insecticide options availa- ble. Teraxxa by BASF is one such product aimed at wireworm in cereals. Anticipat- ed to be released in 2021, its Group 30 active ingredient is broflanilide. Affect- ing the central nervous system of the insect, it causes paralysis and death, the company claims. Another newly available seed treat- ment is Corteva’s Lumivia CPL, the active ingredient of which is Group 28 insecti- cide chlorantraniliprole. It was launched commercially in February of this year. Though the ingredient has been available in other Corteva products for a few years, Lumivia is aimed at wireworm and other pests in cereals, lentils and peas. Also a seed treatment, it is aimed at early-sea- son control. According to the company, it paralyzes the insect’s muscles, leaving it unable to feed and killing a portion of the population. “[Pesticides are] not a silver bullet,” said Catton. “We’ve got to approach this from an integrated way. We don’t want to rely on just one method, because if that method fails, it’s back to square one.” WORMING OUR WAY FORWARD “This isn’t the end for our wireworm work,” said Catton. “I see it as more of a beginning.” She said the results of this complex study will suggest the exact direction fur- ther wireworm research will take. Future projects will evolve around integrated pest control methods and refine the use of wireworm control chemicals. “The goal is to give producers tools and options to manage the pest,” she said. “We’re lacking tools and information. We don’t even have economic thresholds for wireworms. If you did a trap in your field and you found some wireworms, we don’t know how many you need to find to make an economic difference.” In the meantime, farmers can expect new educational materials. To be complet- ed in the immediate future, Catton and her colleagues are writing a wireworm field guide. In plain language, it will detail everything researchers know about the Prairie members of this insect family. The publication will include details on their various lifecycles, the problems and limi- tations presented by control methods and high-resolution photos of the main spe- cies. The guide is expected to be released later in 2020.