Weekly Update (May 25, 2017; Wk 04) - Predicted Grasshopper Development

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 22, 2017, predicted mean embryological development was 70% (66% last week); the greatest development was predicted to be across southern regions in all three provinces (similar to long term averages; Fig. 1).  

Figure 1.  Simulation model outputs mapped to predict the embryological development of Migratory grasshopper  (Melanoplus sanguinipes) eggs across the Canadian prairies as of May 15, 2017).

Model output indicates that development near Regina SK (Fig 2, Top) is slightly greater than Lethbridge AB (Fig. 2, Middle). Hatch in Lethbridge is predicted to be two weeks ahead of model predictions for Grande Prairie AB (Fig 2, Bottom). 

Figure 2. Predicted development of Migratory grasshoppers near Regina SK (Top), Lethbridge AB (Middle), and Grande Prairie AB (Bottom). 

Reminder - The Prairie Pest Monitoring Network's 2017 Grasshopper Forecast Map can be viewed here.  

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.