Thursday 4 June 2020

Bertha armyworm monitoring

Bertha armyworm (Lepidoptera: Mamestra configurata- This week, a pest alert related to the imminent emergence and flight of this season's moths was released.  Portions of that alert have been repeated below.

Based on weather conditions up to May 31, 2020, and model output, BAW adults may begin to emerge by mid June so traps in Alberta, Manitoba, and Saskatchewan should be deployed in the next 7 to 10 days (Table 1; Fig. 1). Trap deployment in the Peace River region should occur approximately 10 days later (Table 1; Fig. 1).


Table 1. The estimated date on which bertha armyworm pupae will have completed 80% of pupal development and when adult moths are expected to begin emerging at six locations across western Canada.

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development across the Canadian prairies projected to June 8, 2020

Over the next weeks, watch your provincial monitoring networks who will weekly compile cumulative pheromone-baited traps in AlbertaSaskatchewan, and Manitoba.

Biological and monitoring information related to bertha armyworm in field crops is posted by the provinces of ManitobaSaskatchewanAlberta 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. 3) 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 3. Stages of bertha armyworm from egg (A), larva (B), pupa (C) to adult (D).
Photos: J. Williams (Agriculture and Agri-Food Canada)