Spring weather to determine Prairies’ crop pest load

MarketsFarm — How problematic insects fare across the Prairies in 2020 depends largely on the weather this spring, according to three provincial insect specialists.

Be the insects grasshoppers, flea beetles, cutworms, or a few other types, their potential to cause significant damage to Prairie crops will partly depend on how dry and warm this coming spring will be.

Grasshoppers could be quite an issue in some parts of Saskatchewan this year, said James Tansey, the provincial specialist for insects/invertebrate pest management in Regina.

For the vast majority of Saskatchewan, grasshopper numbers should be very light, with some greater numbers in the Estevan area. The Kindersley area is expected to see light to severe populations.

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Grasshopper nymphs are susceptible to raindrops as well as cooler temperatures that permit bacteria, fungi and viruses, he said.

Manitoba’s provincial entomologist John Gavloski noted a warm, dry spring would increase grasshopper populations, but also boost populations of their natural predators. He said bee flies, field crickets and blister beetles like to feed on grasshopper eggs.

“Weather and natural enemies will be the two things capable of reducing levels,” Gavloski said.

Manitoba is looking at higher grasshopper populations in the Arborg area of the Interlake, and in the Brandon-to-Russell area in the province’s west.

Alberta provincial entomologist Scott Meers pointed to the province’s south as most likely to have problems later this year with grasshoppers, especially in its south-central and southwest areas. The Peace region may also see increased numbers, he said.

As for flea beetles, Meers said they’ve been a problem in Alberta for the last two years and sees “no reason why they wouldn’t be a problem in 2020.”

If winter should continue to be cold with poor snow cover, he said that could help to bring down their numbers.

Gavloski noted flea beetles caused significant issues in 2019 for Manitoba farmers, and too the beetles’ effect on this year’s crops will be dependent on how well they overwinter.

“I encourage farmers and agronomists to be out early with their crop scouting,” he said.

Saskatchewan doesn’t monitor flea beetles, Tansey said, and there are two naturalized species: the crucifer flea beetle and the striped flea beetle.

Tansey also noted two types of weevils have been problems in the past in the province: the pea-leaf weevil and the cabbage seedpod weevil. Both types have diminished in numbers, but he stressed they are spreading to the north and east, into Manitoba.

As for cutworms, Meers said Alberta doesn’t monitor them and there are always cutworms somewhere in Alberta. Also, Gavloski reiterated the need for early scouting.

— Glen Hallick reports for MarketsFarm, a Glacier FarmMedia division specializing in grain and commodity market analysis and reporting.

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