Why this winter will bug some insects

Extreme winter temperatures could bode well for pest management on farms this spring.

While insects such as wire worms and grubs are instinctive enough to beat any deep frost, other species stay comparatively shallow. That leaves them vulnerable to the exceptional cold temperatures experienced this winter in many parts of Canada.

Dale Cowan, senior agronomist with the Wanstead and AGRIS co-ops in southwestern Ontario, says flea beetles, bean leaf beetles and slugs overwinter in shallower soil than most insects.

Cold temperature impact

As a result - to a greater extent than usual - they might be victims of persistently low winter temperatures.

“We never get the full cleansing effect we want, and because it’s -20C in the air doesn’t mean it’s that cold in the soil,” Cowan says. “But this winter could possibly reduce the presence of some of these insects in the spring.”

Insect pressure depends on several factors, including weather from afar. For example, armyworms can be blown up from the Ohio Valley. That’s a force of nature and can’t be prevented or influenced by winter weather here.

Cowan says that variability means producers need to be diligent with scouting, to spot insects as soon as possible in the spring and initiate control measures where necessary.

Soil watch

Dramatically low winter temperatures might also slow soil warming. If ice stays on the Great Lakes longer than usual, Ontario could be in for a cool spring. That means low soil temperatures.

That’s important for farmers to keep an eye on. Planting into cooler soil can inhibit seed development and germination.

The flip side is that waiting too long to plant reduces yields. 

Get ready to go

Cowan says that while it’s still early, farmers need to start making management plans to get onto the land as early as possible. Weather patterns over the past three springs have been unpredictable. Typically, there’s been an opportune two-week planting window of warm, dry weather, followed by rain and low temperatures that have made planting grind to a halt.

“Farmers who were ready to plant and on their fields early typically are prepared to manage for those risks with timely field observations,” Cowan says.

He says his co-ops are already “very heavy” into crop planning by field, crop and service, and urges producers to start planning early.  

“Stay flexible in the spring,” says Cowan. “The window for planting is very narrow, and management depends on what the weather gives us. We need to be agile.” 

Bottom line

Extreme cold temperatures could reduce some insect pressure, but could also affect soil temperatures. Monitor the situation closely as spring approaches and be ready to plant early if conditions are right.

Article by: Owen Roberts