Weekly Update (Jun 8, 2017; Wk 06) - Predicted Bertha Armyworm Development

Bertha armyworm (Lepidoptera: Mamestra configurata) - Warm conditions over the past week has advanced pupal development across the southern prairies. Compared to last week, adult emergence is predicted to be 1-7 days earlier. The first map shows that pupal development is well underway across southern and central regions. Average development was 70% (50% last week). Pupal development at a number of locations was 75%. 

The second map indicates that development, compared to long-term-average, is slightly greater than average development. Model output indicted that first adult emergence may occur this week in the Vauxhall, Brooks and Regina areas. 

IMPORTANT - The table indicates predicted dates of first appearance of adults for specific locations across the prairies. Adult emergence generally occurs within 5-7 days after 80% development. 

Reminder - The video below posted by Alberta Agriculture and Forestry's Scott Meers describes how pheromone traps are used to monitor this important pest of canola.

Those monitoring BAW pheromone traps may want to compare trap “catches” to the following reference photo kindly shared by Saskatchewan Agriculture below:

Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of Manitoba, Saskatchewan, Alberta and the Prairie Pest Monitoring Network.  Also refer to the bertha armyworm pages within the new "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" - both English-enhanced or French-enhanced versions are available.