Friday, 2 August 2019

Predicted grasshopper development (August 1, 2019; Wk 17)

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).

Based on model runs, approximately 24% of the population should be in the adult stage. Based on climate data, 32% of the population would be expected to be in adult stage. The first map indicates the average instar for grasshopper populations across the prairies (Fig. 1). The second map indicates adult populations are developing across southern MB and SK and a localized area in southern AB (Fig. 2).
Figure 1. Predicted development stages of grasshopper (Melanoplus sanguinipes) populations across
the Canadian prairies (as of July 28, 2019). 

Figure 2. Predicted percent of grasshopper (Melanoplus sanguinipes) populations attaining adult stage across 
the Canadian prairies (as of July 31, 2019). 

The Insect of the Week's Doppelganger featured GRASSHOPPERS for Week 14!!  Check out the excellent nymph photos to help your in-field scouting!

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 "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.