Wheat Midge Survey Map
Wheat midge populations were found to be reduced compared to the 2022 survey. However, some significant hotspots were found north of Regina, and smaller instances of dense populations were found near Saskatoon, Kindersley, and Lloydminster. Never discount the occurrence of wheat midge, even in regions that are sampled anticipating low levels the following year. Favourable environmental conditions, particularly timely rains prior to the end of May can still promote larval development and the emergence of adults in late June/early July.
Please note that the term for this map has changed from the 2024 forecast to the 2023 survey map. There are several factors that can influence next year’s population. One important factor is at least 25 mm of precipitation prior to the end of May is required for proper development; lower levels reduce emergence of adults. Many regions saw inadequate rainfall for development. Emergence can be delayed, extended or erratic and may not coincide with the susceptible stage of the wheat crop.
Importantly, counts greater than 600 wheat midge per square metre (yellow and orange) on the wheat midge map may still result in significant damage and yield loss, especially if springtime environmental conditions are favourable. In 2023, 359 samples were collected to produce the 2023 survey map. Not all fields are sampled. The intention of the survey map is to provide a regional representation of viable wheat midge populations present in the fall of 2023.
To determine midge populations and, if necessary, timing of an insecticide application, growers are urged to monitor conventional wheat fields during the susceptible period – when the wheat head becomes visible as the boot splits until mid-flowering (anthesis). Regular field scouting on successive nights is important to understand wheat midge population changes in a particular field. Temperature and wind conditions significantly influence egg-laying by the adult female midge. High temperatures and high winds tend to reduce activity of egg-laying female midge.
There are options for managing wheat midge. If spring wheat is planned as part of a rotation, there are midge-tolerant wheat varieties available as varietal blends (VB). For 2024, VBs are available in CWRS, CPSR, CWSP, CWSWS, CWHWS, CNHR, CWES, and Durum wheat classes. Visit the Midge Tolerant Wheat Stewardship Team website for information on midge-tolerant wheat and VBs. Also, refer to the Saskatchewan Seed Guide for information.
You can also consider crop rotation to a non-host crop. Since spring wheat is the primary host for wheat midge, planting a non-susceptible cereal crop (e.g. oats, barley) or a broadleaf crop (e.g. canola, pulse) is a good option.