BANFF, Alta. – The cereal leaf beetle. The seedpod weevil. The swede midge.
Those unfamiliar insects could become part of a prairie farmers’ vocabulary in the future.
One of the effects of climate change will be changes in the insect population of Western Canada’s grain growing regions, Agriculture Canada scientist Ross Weiss told a grain industry meeting here last week.
“We will have insects occurring in regions where they don’t occur now and we’ll see insects occurring in potentially greater numbers where they do occur now,” he said in an interview after speaking to the annual meeting of the Prairie Grain Development Committee. “They’ll be able to survive where they can’t now.”
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Take grasshoppers, which are common across most of North America.
“We’d never consider that to be a pest insect in Hay River in the Northwest Territories,” said Weiss. “But once it starts getting warmer and they start growing crops up there, there’s a real potential they could become a big problem.”
Confronting new insects is nothing new for prairie farmers.
As producers have diversified into new crops over the years, that has attracted new insects. Also the constant movement of people and products across the continent has moved insects into new areas.
But climate change presents a new, more serious challenge.
Weiss said the consensus among climatologists is that climate change in general will result in warmer temperatures, more variability in temperatures and more unpredictable and violent precipitation.
By 2040, it’s expected temperatures will increase by two to five degrees in the southern Prairies. The temperature over the entire growing season will be similar to today’s July average.
Weiss predicted it will be hotter and drier, with short, violent rainstorms and less precipitation overall.
All of that will have dramatic effects on the insect populations, altering the time of emergence, development, reproduction rates, activity and feeding patterns and reducing winter mortality.
For example, now the diamondback moth can’t survive the prairie winter and is blown in from the United States and Mexico. That could change with a warmer climate.
Weiss said it’s hard to predict whether the insect problem facing prairie grain farmers will be better or worse as a result of climate change.
“What I can say is that it will be different,” he said.
And just as new insects will invade and thrive, some existing insects may be reduced or even disappear.
Pest insects like disturbance in their environment while non-pest insects prefer stability, so the big winners from climate change will be the pest insects.
There could be some positives for farmers. For example, nights will be warmer, providing the producer with more time to spray and reducing the incidence of killing frosts.
However, those warmer nights will also allow insects like the diamondback moth to lay eggs longer into the night, increasing the potential population.
There will also be a need to develop new insect control methods, including new pesticides, whose performance is often affected by temperature and precipitation.
“We will need new tools, new management practices and more money to reduce the impact of climate change, not only with insects, but for every aspect of our agriculture,” said Weiss.
Don Smith, a plant scientist from McGill University, painted a gloomy picture of the effects of climate change on western Canadian agriculture.
“The Palliser Triangle region could become too dry for commercial cereal production,” he said.
As glaciers shrink and perhaps disappear in the Rocky Mountains, there will be less spring runoff to feed rivers that provide sources of irrigation.
And the combination of drier soils and increased winds will result in significant soil erosion.
If temperatures increase by two to four degrees, there will be some positive and some negative effects, he said. If temperatures increase by four or more degrees, there will be serious negative impacts.
Smith suggested farmers in Western Canada will have to turn to different crops, including more winter wheat and soybeans and new production areas will open up in places like northern Alberta and Saskatchewan and even north of the 60th parallel.
