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 25, 2020, predicted embryonic development (Fig. 1) was 73% (66% last week) and is 5% higher than long term average values.  Development is greatest in a region extending from Winnipeg to Saskatoon to Lethbridge (Fig. 1, Table 1).  

This week, initial hatch is predicted to occur across most of the southern prairies (Fig. 2, Table 1). The simulation estimates that the hatch, based on the prairie average, is 2.9%. Hatch of grasshopper nymphs was predicted to be most advanced in the region extending from Regina to the U.S. border.  

Figure 1. Grasshopper embryological development (%) based on model simulations using
current environmental conditions (as of May 25, 2020).

Figure 2. Predicted percent of grasshopper (Melanoplus sanguinipes) population at hatching stage across
the Canadian prairies (as of May 25, 2020). 

Table 1. Predictive model output estimates for M. sanguinipes at selected sites across the Canadian prairies (as of May 25, 2020).

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" (Philip et al. 2018) as an English-enhanced or French-enhanced version.