Bertha armyworm monitoring

Bertha armyworm (Lepidoptera: Mamestra configurata) - Model simulations to June 14, 2020, indicate that pupal development is greater than 90% across most of Saskatchewan and Manitoba.  Pupal development is predicted to be slower across central and northern regions of Alberta.  First occurrence of BAW should be occurring in isolated regions across southern Alberta, Saskatchewan and Manitoba. In fact, adult BAW were reported in Saskatoon by Dr. Julie Soroka on June 17, 2020.  By next week adults should be emerging across most of the prairies.  

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development across
the Canadian prairies as of June 14, 2020. 

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 "Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and management field guide" which is a free downloadable document as both an English-enhanced or French-enhanced version.

Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting.  Use the images below (Fig. 2) to help identify egg masses and the economically important larvae in canola.  Review the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm!

Figure 2. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D).
Photos: J. Williams (Agriculture and Agri-Food Canada)