Predicted bertha armyworm development (June 20, 2019; Wk 11)

Bertha armyworm (Lepidoptera: Mamestra configurata) - Pupal development is progressing and this week adults should be occurring across most of southern SK and localized areas in AB.  Most of the population is predicted to be in the pupal stage (89%). The BAW model indicates that 10% of the population is in the adult stage .

Figure 1. Predicted precent of bertha armyworm (Mamestra configurata)  populations at adults stage across the Canadian prairies as of June 17, 2019. 

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.

Again, thanks to John Gavloski (Manitoba Agriculture) who helped update the PPMN Bertha armyworm monitoring protocol.  Use the images below (Fig. 2) to help identify moths from the by-catch that will be retained in phermone-baited unitraps.

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

Also be sure to review the Insect of the Week which features bertha armyworm and its doppelganger, the clover cutworm!