Insects are always a challenge for farmers on the prairies. The unpredictable weather in Manitoba played a significant role in shaping that province’s insect activity in 2024. According to John Gavloski, an entomologist with Manitoba Agriculture, the cold, wet spring had both positive and negative effects on various pest populations. Gavloski shared insights into the challenges farmers faced and what they can expect heading into 2025.
Flea Beetles: A Persistent Concern
One of the most significant challenges for Manitoba canola growers remains flea beetles. These small black beetles, which feed on crops in the cabbage family, including canola, caused widespread damage in 2024.
“Flea beetles are a chronic concern,” Gavloski explained. “The seed treatments used to manage them are effective for about three to four weeks after seeding. But when you get cool weather, like we did this spring, it slows crop growth, leaving seedlings vulnerable for longer. That’s when flea beetles can really become a problem.”
With flea beetles being a consistent threat, Gavloski urged farmers to be prepared for high levels of activity in 2025.
Cutworms, Weevils, and Other Challenges
Cutworms were another notable pest in 2024, though Gavloski noted that their populations have been declining compared to recent years. “Cutworms were still a concern in most agricultural regions, but they weren’t as bad as what we saw back in 2019 or 2020,” he said.
Alfalfa growers dealt with significant feeding damage from alfalfa weevils, which Gavloski described as beetles with a snout-like feature. “When alfalfa weevils are abundant, their feeding can make fields look frosted,” he said. “This was a problem in many areas of the province.”
In the western part of Manitoba, Bertha armyworms posed a threat to canola crops, while aphids caused issues in cereal crops, peas, and soybeans. Gavloski highlighted the impact of pea aphids in particular: “Pea aphids feed on the newer growth of pea plants and can cause real trouble when they target developing pods. This was an issue for many growers this year.”
Nature’s Allies: Beneficial Insects
Despite the challenges, natural predators played a vital role in managing pest populations. “We saw high levels of natural enemies like lady beetles, lacewings, and parasitic wasps,” Gavloski shared. “These predators are a big help, especially when it comes to controlling aphid populations. It’s always encouraging to see them thriving.”
Grasshoppers Decline in 2024
Grasshoppers, a pest that has been problematic in recent years, were less of an issue in 2024. Gavloski attributed this to the wet, cool conditions early in the season. “Young grasshoppers are very vulnerable right after they hatch,” he explained. “If it’s cold and rainy, their survival rates drop significantly. That’s likely why we saw lower grasshopper numbers this year.”
Newcomers on the Radar
Manitoba is also tracking two newer pests: the cabbage seed pod weevil and pea leaf weevil. These insects, which arrived in the province within the past few years, are gradually expanding their range.
“The cabbage seed pod weevil feeds inside canola pods, but thankfully, its levels remain very low,” Gavloski said. “We’re keeping a close eye on it, especially as it moves eastward.”
The pea leaf weevil, first identified in the Swan River Valley, is also spreading. “We’re starting to see higher levels in the northwest, particularly in areas like Russell and Roblin,” Gavloski noted. “Growers in those regions should familiarize themselves with this pest and monitor their fields closely.”
Preparing for 2025
Looking ahead, Gavloski emphasized the importance of vigilance and monitoring. “It’s hard to predict insect activity for 2025 because so much depends on the weather,” he said. “But farmers should definitely be prepared for flea beetles, cutworms, and grasshoppers. We also recommend keeping an eye on emerging pests like the cabbage seed pod weevil and pea leaf weevil.”
While pests are a perennial challenge for Manitoba farmers, Gavloski remains optimistic. “Every year brings its own set of challenges, but with proper monitoring and management, farmers can stay ahead of the curve.”