The June 21st Prairie Pest update covers a lot of ground with information on a variety of insects for farmers to be aware of covering insect identification, scouting tips, potential issues and more.
Dr. Meghan Vankosky, a field crop entamologist with Agriculture and Agri-Food Canada, works with her AAFC and her provincial counterparts in Manitoba, Saskatchewan and Alberta in putting together the weekly report and identifying any potential issues.
She says with all the rain we've seen this year, farmers are being reminded to be out scouting crops for any signs of wheat midge.
Wheat midge is expected to be a problem in the prairies this year, and should be out scouting fields on a regular basis for the insect now through early July,
"Last year, in our annual survey in the fall, wheat midge population densities in the soil were quite low across most of the prairies. With some notable hot spots where it was wetter. Which would make us think that the risk for wheat midge could be low this year, but because it's been raining and because it's been raining quite significantly in a lot of places across the prairies from the beginning of May. The wheat midge risk could be higher this year than we originally anticipated."
Wheat midge looks like a small orange fly and tends to be most active on a calm evening, about an hour or so before sunset and just after.
Producers should be scouting fields on a regular basis, not just from the truck but getting out and walking through the crop to see what's happening.
Another insect producers should have on the radar is the diamondback moth.
The Prairie Pest Monitoring Network Newsletter for week 7 identifies the diamondback moth as having a voracious appetite for canola, mustard, flix weed and vegetables like broccoli, brussel sprouts, cauliflower and kale.
Vankosky notes in the article that when the larvae first hatch, they are very small and tunnel inside the leaves to eat, resulting in damage that looks like shot-holes and leaf mines.
"It can have multiple generations per year and that leads to increasing population densities that can kind of sneak up on us if we're not watching for it. So it's important to be scouting for them and we could be starting to see the start of the flight of the first local generation."
The third and fourth instar larvae can consume entire leaves, as well as the buds, flowers and developing pods.
When scouting for diamondback moths, farmers will want to examine the plants for larvae and estimate the number of larvae per m2 to determine if the population is nearing or has exceeded the economic threshold.
In canola, the economic threshold for diamondback moth larvae is 100-150 larvae/m2 when canola plants are immature and flowering. The threshold is 200-300 larvae/m2 when canola plants are mature.
Biological and monitoring information for DBM (including tips for scouting and economic thresholds) is posted by Manitoba Agriculture, Saskatchewan Agriculture, and the Prairie Pest Monitoring Network.
Vankosky says another insect that we could see problems with this year is the migratory true armyworm which has started showing up in phermone traps in Manitoba and Saskatchewan.
The insect migrates in from the United States and is starting to show up in phermone traps in Manitoba and Saskatchewan.
"This is a cereal pest that likes to eat things like rye, barley, wheat, other native grasses, oats and things like that. So it could be important in some parts of the prairies at least to be aware that true armyworm could be out there and it could be something that we'll have to scout for and watch for as the season progresses."
She says the damage is similar to what we might expect to see with grasshoppers or bertha armyworm.
"So if you're seeing chewing damage on the leaf margins of your grains, then the next thing to do is to start looking for the caterpillars. The larvae hide in the leaf litter during the day and tend to be up on the plants later in the evening and overnight. So if you're not seeing a lot of grasshoppers flopping around and you're seeing damage that looks like grasshopper damage. Then route around in the soil a bit and see if you can find any caterpillars that might be doing that damage and those would potentially be true armyworm larvae."
Vankosky notes Dr John Gavloski has a great article, scouting information and pictures in the Manitoba Agriculture's Crop Pest Update.
More information on the True Armyworm Monitoring program in Manitoba can be found here, an armyworm fact sheet is available here.
To hear Glenda-Lee's conversation with Dr Meghan Vankosky on insects of concern click on the link below.
The Prairie Pest Monitoring Network weekly update is free to subscribe click here.