Thursday 9 May 2019

Predicted grasshopper development (May 9, 2019; Wk 05)

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).  

This week, cool temperatures this week were predicted to result in minimal embryological development. As of May 7, 2019, predicted development was 60% and is similar to long term average values (Fig. 1). As embryological development approaches 100%, scouting for  nymphs of pest species of grasshoppers should begin.


Figure 1.  Predicted grasshopper (Melanoplus sanguinipes) embryological development across
the Canadian prairies as of May 7, 2019. 




Reminder - The Prairie Pest Monitoring Network's 2019 Grasshopper Forecast Map was released in March.  Review all the current risk and forecast maps by linking here.  While spring temperatures, soil moisture conditions, and precipitation can all have an impact on overwintered grasshopper eggs, areas highlighted orange or red in the 2019 forecast map should be vigilant this spring by performing in-field scouting to assess nymph densities.


Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba AgricultureSaskatchewan AgricultureAlberta 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.