Friday, 16 June 2017

Weekly Update (Jun 15, 2017; Wk 07) - Predicted Grasshopper Development

Grasshopper Simulation Model Output – Simulation modelling is used to predict grasshopper development across the prairies. Weekly temperature data is incorporated into the model which calculates estimates of grasshopper development stages based on biological parameters for Melanoplus sanguinipes (Migratory grasshopper). Predicted hatch for June 11, 2017, was 52% (23% last week) with 32% of the population in the first instar, 15% second instar and 15% third instar. 

The greatest development was predicted to be across southern regions in all three provinces, particularly southeastern Alberta and a region extending south from Swift Current/Regina to the US border. 

Grasshopper populations near Saskatoon were predicted to be primarily in the second instar with appearance of some third and fourth instars. This week’s survey (southwest of Saskatoon) agreed with model predictions with first collections of a few fourth instars.  

Model output for Grande Prairie indicates that development continues to be approximately 10 days later than locations across the southern prairies.

Reminder:  Biological and monitoring information related to grasshoppers in field crops is posted by Manitoba Agriculture, Food and Rural DevelopmentSaskatchewan 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.