Predicted bertha armyworm development (May 24, 2018; Wk 03)

Bertha armyworm (Lepidoptera: Mamestra configurata) - Bertha armyworm (BAW) – BAW pupae, developing in the soil, are predicted to be ahead of average development. Pupal development is predicted at approximately 50% (Fig. 1) whereas the long term average is 36%. 

Figure 1.  Predicted bertha armyworm pupal development across the prairies as of May 21, 2018.

Model output predicts that emergence may begin as early as June 9th for the Regina area. Development is expected to be 5-6 days faster than average (Fig. 2; Table 1).

Figure 2. Predicted bertha armyworm phenology at Regina SK. Values are based on
model simulations, for April 1 – May 21, 2018 (projected to June 30, 2018).

Table 1. Projected dates for bertha armyworm adult emergence.

Reminder - Review the 2017 bertha armyworm distribution map for the Canadian prairies which reports cumulative pheromone trap counts intercepting male moths during the 2017 growing season.

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.