2020 Grasshopper Forecast

From the Saskatchewan Ministry of Agriculture:

The 2019 Grasshopper Survey was completed on 1,160 sites throughout Saskatchewan in August. Light populations were seen throughout the province, with some exceptions. Most moderate counts (five to 10 m2) were found in the southeast, with a few moderate counts near Saskatoon, Biggar and Rosetown. The highest populations (more than 10 m2) were seen primarily in the southeast. Populations of more than 20 m2 were detected near Kindersley. The action threshold for grasshoppers is 10 to 12 m2 in most crops, and 2 m2 in flax and lentil. Two-striped grasshoppers were indicated as dominant where species identification occurred.

The survey and forecast map are intended to provide general information on risk levels. The actual severity of grasshopper infestations may differ from the 2020 Forecast Map, depending on weather conditions in the spring. Hot and dry conditions favour growth and development of grasshoppers.

Not all grasshoppers are crop pests. The grasshopper survey is intended to consider annual species because they have a greater potential for rapid increase in populations. Grasshoppers that are already winged adults before June, that have coloured wings or that make audible sounds are considered non-pest species and rarely cause economic damage. Many of these are rangeland species, require two years to complete their life-cycle and do not tend to increase to economically damaging numbers.

Growers should monitor for young grasshoppers in susceptible crops in the spring and early summer. Lentil flowers and pods and developing green bolls in flax are especially vulnerable to grasshopper feeding. In both of these crops, grasshoppers feed on reproductive parts of the plant rather than foliage and, therefore, have a more direct effect on yield with a lower economic threshold of two grasshoppers per square metre.

Contact the Agriculture Knowledge Centre's general inquiry line (1-866-457-2377) for further information on grasshoppers and updates during the 2020 growing season.