TEMPERATURE: The 2022 growing season has been cooler than normal, particularly in Manitoba. This past week (May 30 – June 5, 2022) average daily temperatures were similar to the previous week. The average temperature across the prairies was 1 °C cooler than normal (Fig. 1). Temperatures were warmest in Alberta and coolest in Manitoba.
Average 30-day temperatures (May 7 – June 5, 2022) were warmest in southern Manitoba and southeastern Saskatchewan (Fig. 2). The average temperature across the prairies was similar to long-term average values. Temperature anomalies (difference between observed and climate normals) over the past 30 days indicate that temperatures across southern Saskatchewan and southern Alberta were cooler than average (Fig. 3).
The growing season (April 1 – June 5, 2022) has been cooler in Manitoba than in Saskatchewan and Alberta (Fig. 4; Table 1). The average growing season temperature for the prairies has been 1.5 °C cooler than climate normal values.
PRECIPITATION: Rainfall has been well below normal for Alberta and western Saskatchewan while rainfall amounts have been well above normal for eastern Saskatchewan and Manitoba in 2022. Seven-day cumulative rainfall ranged between 0 and 62 mm with the highest rainfall amounts occurring across Manitoba (Fig. 5). This week southwestern Saskatchewan and southern Alberta received 10-20 mm of rain.
Rain (30-day accumulation) amounts have been well above average across the eastern prairies, particularly southeastern Manitoba; rain amounts have been well below normal in Alberta and western Saskatchewan (Figs. 6 and 7).
Growing season rainfall for April 1 – June 5, 2022, continues to be greatest across Manitoba and eastern Saskatchewan; conditions have been well below normal across most of Saskatchewan and Alberta (Fig. 8; Table 1).
The grasshopper (Acrididae: Melanoplus sanguinipes) model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest. Review the historical grasshopper maps based on late-summer adult in-field counts performed across the prairies.
Model simulations were used to estimate percent grasshopper egg development and hatch as of June 5, 2022. Recent warmer temperatures in Saskatchewan and Alberta have resulted in increased rates of grasshopper development. In contrast, cooler/wetter conditions across eastern Saskatchewan and Manitoba have resulted in delayed development. Last week, average embryological development was 73%.
This week, average egg development is predicted to be 76% and is similar to the long-term development rate (Fig. 1). Hatch is progressing across southern and central regions of Alberta and Saskatchewan (Fig. 2). This week grasshoppers (1-3rd instars) were abundant at specific locations across west-central Saskatchewan. Some fields were showing signs of grasshopper feeding.
Risk estimates, based on meteorological inputs, were used to assess the impact of weather on potential grasshopper development and population growth potential (Fig. 3). A bioclimate simulation model was developed to assess how climatic factors influence occurrence and relative abundance. Potential risk is based on weekly growth index values. Grasshopper risk is greatest in areas that are warmer and drier than normal. As of June 5, 2022, model output indicates that potential risk is greatest across eastern Alberta and western Saskatchewan. Cooler/wetter conditions in eastern Saskatchewan and Manitoba are predicted to reduce potential risk.
Hatch is progressing across southern Alberta and western Saskatchewan (Fig. 3). Last week, grasshopper hatchlings were collected in an area between Saskatoon and Kindersley. Southern Alberta and western Saskatchewan have received the least amount of rain during the growing season. Grasshopper risk can be greater when conditions are warm and dry.
The alfalfa weevil (AAW) (Curculionidae: Hypera postica) model predicts development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.
Model simulations for alfalfa weevil (AAW) indicate the appearance of first and second instar larvae should be occurring across the prairies. Development in southern Manitoba (Fig. 1) is slower than development in southern Alberta (Fig. 2). Development is similar to long-term average values.
Additional information can be accessed by reviewing the Alfalfa Weevil Page extracted from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page.
The cereal leaf beetle (CLB) (Chysomelidae: Oulema melanopus) model predicts larval development using biological parameters known for the pest species and environmental data observed across the Canadian prairies on a daily basis. Review lifecycle and damage information for this pest.
Warmer conditions in southern Alberta and southwestern Saskatchewan are predicted to result in more rapid development of cereal leaf beetle (CLB) populations compared to southern Manitoba. CLB model output suggests that the hatch should be nearly complete for southern Alberta and Saskatchewan. First and second instar are predicted to be present in these areas (Fig. 1). As a result of cooler conditions, egg development is predicted to be delayed in southern Manitoba (Fig. 2). First instar larvae should begin to occur by the end of this week in Manitoba.
Access scouting tips for cereal leaf beetle or find more detailed information by accessing the Oulema melanopus page from the “Field crop and forage pests and their natural enemies in western Canada – Identification and management field guide” (2018; accessible as a free downloadable PDF in either English or French on our new Field Guides page.
Compared to average development, bertha armyworm (BAW) pupal development in 2022 continues to be delayed for the Peace River region, Manitoba and southern and eastern regions of Saskatchewan (Fig. 1). Pupal development across southern and central Alberta and Saskatchewan is similar to long-term average values. Development in this region is 60-75% complete.
We suggest that BAW pheromone traps be placed in fields when pupal development is 75-80% to ensure that traps are in place prior to emergence of adults. Based on current runs, it is advisable that traps for Alberta and Saskatchewan be placed in fields by the end of this week (June 6-10). Traps should be put out in Manitoba and the Peace River region next week.
Wheat midge (Sitodiplosis mosellana) overwinter as larval cocoons in the soil. Soil moisture conditions in May and June can have significant impacts on wheat midge emergence. Adequate rainfall promotes termination of diapause and movement of larvae to the soil surface where pupation occurs. Insufficient rainfall in May and June can result in delayed movement of larvae to the soil surface. Elliott et al. (2009) reported that wheat midge emergence was delayed or erratic if rainfall did not exceed 20-30 mm during May. Olfert et al. (2016) ran model simulations to demonstrate how rainfall impacts wheat midge population density. The Olfert et al. (2020) model indicated that dry conditions may result in: a. Delayed adult emergence and oviposition b. Reduced numbers of adults and eggs
As of June 5, 2022, normal to above normal rainfall in Manitoba, eastern Saskatchewan and the British Columbia Peace River region should be sufficient to promote the movement of wheat midge larvae to the soil surface this year (Fig. 1). Warmer temperatures in central Manitoba are expected to advance larval development over the next seven days. Current development for eastern Saskatchewan and Manitoba is similar to long-term average rates.
Additional information can be accessed by reviewing the Wheat midge pages extracted from the “Field Crop and Forage Pests and their Natural Enemies in Western Canada: Identification and Field Guide” (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page.
1. REVERSE TRAJECTORIES (RT) Since May 1, 2022 the majority of reverse trajectories that have crossed the prairies originated from the Pacific Northwest (Idaho, Oregon and Washington) (Fig. 1). Relative to previous weeks, there was a significant decrease in the number of trajectories that were predicted to cross over the prairies from May 31 – June 6, 2022. This week reverse trajectories generally originated over the arctic before entering the prairies.
a. Pacific Northwest (Idaho, Oregon, Washington) – The majority of Pacific Northwest reverse trajectories have been reported to pass over southern and central Alberta and western Saskatchewan (Fig. 2). This past week (May 31-June 6, 2022) the ECCC model predicted that 26 reverse trajectories passed over the prairies. This is a significant decrease compared to the previous week (n=124).
b. Mexico and southwest USA (Texas, California) – This past week (May 31 to June 6, 2022) reverse trajectories that originated from Mexico, California or Texas crossed over Carman and Selkirk (May 31, 2022). Since April 1, reverse trajectories were reported for Manitoba (Portage, Selkirk, Brandon, Carman, Russell) and eastern Saskatchewan (Gainsborough, Grenfell) (Fig. 3).
c. Oklahoma and Texas – Since April 1, reverse trajectories were reported for Manitoba and eastern Saskatchewan (Fig. 4). This past week (May 31 to June 6, 2022) there has been an increase in the number of reverse trajectories that have crossed over southeastern Saskatchewan (Weyburn and Gainsborough) and Manitoba (Portage and Brandon).
d. Nebraska and Kansas – Reverse trajectories, originating from Kansas and Nebraska, have crossed southeastern Saskatchewan and southern Manitoba (Fig. 5). This past week (May 31 to June 6, 2022) the ECCC model predicted that 6 reverse trajectories passed over the prairies. This is a significant decrease compared to the previous week (n=27).
2. FORWARD TRAJECTORIES (FT) The following map presents the total number of dates (since April 1, 2022) with forward trajectories (originating from Mexico and USA) that were predicted to cross the Canadian prairies (Fig. 6). This week (May 31 to June 6, 2022) there were fewer (n=12) forward trajectories predicted to cross the prairies than the previous week (n=45). Results indicate that the greatest number of forward trajectories entering the prairies have originated from the Pacific Northwest (Idaho, Oregon, Washington), Montana and Wyoming.
View historical PPMN wind trajectory reports by following this link which sorts the reports from most recent to oldest.
Provincial entomologists provide insect pest updates throughout the growing season so link to their information:
MANITOBA’SCrop Pest Updates for 2022 are up and running! Access a PDF copy of the June 8, 2022 issue here. Bookmark their Crop Pest Update Index to readily access these reports and also bookmark their insect pest homepage to access fact sheets and more! • Diamondback moth pheromone trap monitoring update for MB – “So far, diamondback moth has been found in 25 traps. Levels are generally very low, with the exception that some moderate counts have occurred in the Eastern and Central region, particularly over the past few weeks.” Read the report on Page 7 of the June 8, 2022 issue OR review a more detailed summary of cumulative trap counts from 38 sites deployed across the province. • Armyworm pheromone trap monitoring is underway in MB – “So far, counts have generally been quite low, with armyworm moths only being caught in 6 traps.” Read the report on Page 7-8 of the June 8, 2022 issue.
ALBERTA’SInsect Pest Monitoring Network webpage links to insect survey maps, live feed maps, insect trap set-up videos, and more. There is also a Major Crops Insect webpage. The new webpage does not replace the Insect Pest Monitoring Network page. Remember, AAF’s Agri-News occasionally includes insect-related information. Twitter users can connect to #ABBugChat Wednesdays at 10:00 am. • Diamondback moth pheromone trap monitoring update for AB – Cumulative counts arising from weekly data are available so refer to the Live Map. So far, low numbers of diamondback moth have been intercepted across the province. • Cutworm live monitoring map for AB – Reports are starting to come in so refer to the Live Map to review areas where cutworms are being found. So far, black army and pale western cutworms have been reported. Use this online form to report cutworms in Alberta.