Weekly Update (May 11, 2017; Wk 02) - Predicted Grasshopper Development (Olfert, Giffen, Weiss)

Grasshopper Simulation Model Output – The grasshopper simulation model will be used to monitor grasshopper development across the prairies. Weekly temperature data collected across the prairies is incorporated into the simulation model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper).  

As of May 8, 2017, predicted mean embryological development was 62% (56% last week); the greatest development was predicted to be across southern Saskatchewan. Embryological development was very similar to long term averages (60%) though well behind 2016 (74%). Hatch was not predicted for any locations. 

Reminder - The Prairie Pest Monitoring Network's 2017 Grasshopper Forecast Map (Figure 1) was released in January.  While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, growers in areas highlighted orange or red in the map below should be vigilant as nymphs begin to hatch this season.

Figure 1. Prairie Pest Monitoring Network's 2017 Grasshopper Forecast Map.

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural Development, Saskatchewan Agriculture, Alberta Agriculture and Forestry, the BC Ministry of Agriculture and the Prairie Pest Monitoring Network.  Also refer to the grasshopper pages within the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" as an English-enhanced or French-enhanced version.