close up of common cutworm on leaves

By Harry Brook

We still have a lot of winter to go, but now is the time of year for the insect forecast maps to come out from Alberta Agriculture. Throughout the summer and fall, many people are involved in surveying the risk to crops from an assortment of insect pests. In late January, Alberta Agriculture posts their forecast maps for the following year. Usually, in dry years, insects are a growing problem. How is next year looking?

There are a number of pest surveys but they aren’t all the pests out there. Cutworms are difficult to predict but usually are a problem in southern Alberta. As eggs are mostly laid in the summer and fall, they can show up throughout the province. There is a small, real-time survey of cutworms as they are found in the spring. There are a number of damaging cutworms species found in the province and each one has its own preferred hosts. For more information on cutworms, click HERE to follow this link to an AAF Canada publication.

The existing surveys and predicted results are for Bertha armyworm (on canola), grasshoppers, wheat midge, cabbage seed pod weevil, pea leaf weevil, diamondback moth, cutworms and wheat stem sawfly. The cutworms, Bertha armyworm, diamondback moth, cabbage seedpod weevil and pea leaf weevil surveys are done in real time in May, June and July. Their maps can be an indication of hotspots developing. Also, if these insects are a problem in one year, there is a good chance they will be causing a problem the following year. When checked regularly, they indicate outbreaks before they become extensive. Think of the surveys as an early warning tool. It still doesn’t replace getting out and checking your fields yourself. Insect outbreaks can be very site specific and damaging. I once was in a field with over 50% damage to canola from Bertha armyworm, while a mile away there was almost no damage and the armyworm was hard to find.

The grasshopper survey, wheat stem sawfly survey and wheat midge surveys occur in the fall. They use the presence of larvae or adults to predict areas that might be a problem the following year. The dry, warm fall in 2021 was ideal for grasshoppers to lay their eggs and their numbers are on the rise. Let’s hope the predators and diseases that attack grasshoppers will keep them under control in 2022.

To check out the existing maps for 2022, click HERE. Currently, there are only updated survey maps for the wheat stem sawfly and wheat midge. The grasshopper survey should be posted soon.

Additional to the actual surveys posted, Alberta Agriculture also keeps an eye out for new, invasive insects that could harm our agricultural industry. This surveillance is helped by everyone being aware of these pests and keeping an eye out for them. The insect pest list to watch for is extensive, but early warning and identification can allow us to eradicate them before they become established. Some of the agricultural pests to be watching for include the brown marmorated stinkbug, Japanese beetle, lesser grain borer, and Swede midge. If you find an unusual insect causing damage in your crop or back yard, contact This email address is being protected from spambots. You need JavaScript enabled to view it. for identification.

Being forewarned is forearmed; be vigilant and pay attention.

Harry Brook is Flagstaff County's Agricultural Fieldman. He can be reached via email at: This email address is being protected from spambots. You need JavaScript enabled to view it. or by phone at: 780-384-4138.