Predicted grasshopper development (May 10, 2018; Wk 01)

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 6, 2018, predicted mean development was 62% (slightly greater than long term average of 56%).  The greatest development was predicted to be across southern AB (Fig. 1).

Figure 1. Grasshopper embryological development (%) based on model simulations, for April 1 – May 6, 2018.

Reminder - The Prairie Pest Monitoring Network's 2018 Grasshopper Forecast Map was released in March.  Review all the risk and forecast maps by linking here.  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 this spring.

Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, 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.