Predictive Model Updates

Timing scouting activities is important. In addition to the Weekly Update, updated phenology models for insect pests on the Canadian prairies will be posted here during the growing season, especially when this information may help time scouting or management activities. Posts on this page will be accompanied by Twitter updates if you follow @vanbugsky.


Bertha armyworm emergence update: June 6, 2018

Cool, wet weather across the Prairies last week has slightly delayed emergence of bertha armyworm adults. Model predictions using weather data up to Monday June 4, 2018 now predict that pupal development is 80% complete and first emergence may occur as early as June 6, 2018.

Table 1. Projected dates of adult bertha armyworm emergence at five locations in western Canada.
Location
Predicted Emergence Date
LTN* Emergence Date
Regina
June 9, 2018
June 15, 2018
Saskatoon
June 7, 2018
June 17, 2018
Brandon
June 7, 2018
June 15, 2018
Edmonton
June 6, 2018
June 23, 2018
Grande Prairie
June 16, 2018
June 23, 2018

*Prediction based on long-term normal weather data.
(Weiss and Vankosky 2018)



Bertha armyworm emergence update, May 30, 2018

Accumulation of heat units in the last week, due to warmer than normal temperatures in late May, have pushed the predicted timing of bertha armyworm emergence forward by 3 to 5 days compared to model predictions included in the May 24 Weekly Update (Table 1). Pheromone traps for bertha army monitoring should be placed in the field when mean pupal development is 80% complete. This milestone will be reached in the next few days.

Table 1. Date of predicted first emergence of adult bertha armyworm at 5 locations across the prairies in 2018.
Location
Emergence predicted May 30
Emergence predicted May 24
Emergence predicted by LTNM*
Regina
June 6, 2018
June 9, 2018
June 15, 2018
Saskatoon
June 7, 2018
June 11, 2018
June 17, 2018
Brandon
June 8, 2018
June 12, 2018
June 15, 2018
Edmonton
June 5, 2018
June 12, 2018
June 23, 2018
Grande Prairie
June 13, 2018
June 17, 2018
June 23, 2018

*Long-term normal model 
(Weiss and Vankosky 2018)