As crops begin to emerge across the Prairies, farmers are being reminded to regularly scout their fields for insect activity. Dr. Meghan Vankosky, a field crop entomologist with Agriculture and Agri-Food Canada, emphasizes the importance of vigilance, particularly concerning grasshoppers.
"Last fall, grasshoppers had ample time to lay eggs, and with the warm weather this spring, there's a significant risk to crops," Vankosky explains. "Reports of first instar nymphs have already surfaced near the US border, although recent wet weather in eastern Saskatchewan and Saskatoon might slow them down."
Farmers in southern regions are especially advised to be on the lookout. Vankosky notes that AAFC and provincial authorities have commenced their annual surveys and set up monitoring stations to track field crop pest activity. This data is shared through the Prairie Pest Monitoring Network and its weekly reports, available to subscribers free of charge.
Another insect of concern is the pea leaf weevil. "In southern Alberta, fields are showing feeding damage from adult pea leaf weevils," says Vankosky. "Southern Alberta has been a hotspot for this pest, and as surveys extend into Saskatchewan and Manitoba, we aim to keep farmers informed."
Last year, pea leaf weevil hotspots included southern Alberta, the Edmonton area, and northern Saskatchewan. The population is also growing in Manitoba, particularly in the Swan River Valley area. Vankosky notes that wetter areas have seen healthier weevil populations, shifting the threat to the northern Prairie region.
For canola growers, a key insect in the spring is flea beetles.
Keith Gabbert, an agronomy specialist with the Canola Council of Canada, says they tend to be a problem right across the prairies.
He says the challenge with canola is to get it to that four-leaf stage, happy, healthy, and growing. On occasion, growers will go out in their field and find that flea beetles are happier than the canola is. So really the focus at this point in the year should be scouting and understanding what the risks are.
"The first thing you're looking for is those shot hole marks or pitting," he says, "for the seed treatments that we use the flea beetles need to take a bite. If the flea beetle seed treatment is going to be successful".
A little bit of feeding is to be expected, but if you see a lot of feeding or if you see some stem feeding underneath, it's a cause for concern.
He points out that 10 per cent feeding damage or defoliation on codeletion or the first leaf can look really quite drastic, but 25 per cent defoliation is sort of the action threshold. If we knew that these flea beetles were going to give up and that you had some good soil moisture and growing conditions were going to be good.
"We understand that these plants can come back with 50 per cent defoliation," he says, "but we don't ever really want to see a field get there. Actually, we'd recommend that growers get out and scout if they're at all concerned and they're approaching that 20 per cent defoliation."
Gabbert suggests going to the retailer and making sure they've got some insecticide available.
"A little pre-planning because we can see the 25 per cent level ramp up to 50 in as little as a day." He says, "if it's really hot and dry and you've got very few plants, these flea beetles can do a lot of damage in a short amount of time."
He notes that older research out of Saskatoon would indicate that the crucifer flea beetle (in this case) feeding would double with every five-degree increase in temperature between 5 and 25 degrees when they did the work.
"So they really do eat a lot more above 20 degrees than they would below 15 degrees.
Overall, he says increased temperatures should mean increased scouting.
To hear Glenda-Lee's conversation with Canola Council of Canada Agronomy Specialist Keith Gabbert and Dr. Meghan Vankosky a field crop entomologist with AAFC click on the link below.
Farmers are encouraged to stay updated on pest activity and take necessary precautions to protect their crops.
For more information on these and other crop pests, subscribe to the free weekly Prairie Pest Monitoring Network.