2023 Saskatchewan Grasshopper Survey
Significant and damaging grasshopper populations were seen in 2023 in Central, West, Southwest, and far Southeastern regions. Large numbers, coupled with an early, warm weather-driven hatch of two-striped grasshopper led to the need for early and significant control efforts in many fields and in a variety of crops. Warm weather also contributed to rapid development of adults and early onset of egg laying. Two-striped grasshopper was by far the most prevalent species, but significant numbers of lesser migratory grasshopper were also seen. A long, dry period in July and August in much of the province allowed for good conditions for egg laying and embryo development and will likely contribute to continued grasshopper pressures in 2024.
This survey targets to assess four roadside sites per RM for grasshopper density. High local populations may not be reflected in this map. 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 populations including the numbers of grasshoppers present in a region. These include temperature and precipitation, both during the current growing season and in the following spring.
Outside of the formal survey high grasshopper populations were reported in the Rosetown and Outlook areas. These populations were not seen in the survey but were significant in localized areas.
2023 Survey Results and Forecast Summary
The annual grasshopper survey indicated significant populations of pest species in western and southwestern growing areas as well as elevated populations in central regions and some large populations in southeastern regions. The major factors contributing to risk for the upcoming season are the likelihood of mating and warm dry conditions in the late summer that support successful egg laying. Work by Ross Weiss with Agriculture and Agri-Food Canada indicated the area with elevated oviposition index (an indicator of the suitability of area for egg laying) were greater in 2023 than are normally seen for large areas of western and southern Saskatchewan. Overwintering conditions can also contribute to grasshopper populations. Although the primary pest species on the Prairies are cold hardy, there was a marked decrease in temperatures before significant snowfall occurred in many regions. This may contribute to some overwintering mortality but, given the likely high numbers of eggs that were deposited in 2023, large numbers of hatchlings are still expected for 2024. Finally, warm dry spring conditions contribute to early hatching, greater activity and rapid development of juvenile grasshoppers. The Environment Canada seasonal forecast indicated increased likelihood of elevated spring temperatures extending into June with uncertain levels of precipitation.