Predicted grasshopper development (June 20, 2019; Wk 11)

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).

Across the prairies, the grasshopper hatch is well underway this week with most locations having approximately 51% hatch (30% last week). Based on model runs, (i) approximately 30% (21% last week) of the population is in the first instar, (ii) 14.5% (7% last week) is predicted to be in the second instar, and (iii) 4.3% (1% last week) in the third instar.   

Figure 1.  Predicted development stages of grasshopper (Melanoplus sanguinipes) populations across

the Canadian prairies (as of June 17, 2019). 

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 "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" which is available as a free downloadable document in either an English-enhanced or French-enhanced version.