Released June 10, 2022

This week includes…..

• Weather synopsis
• Predicted grasshopper development
• Predicted alfalfa weevil development
• Predicted cereal leaf beetle development
• Predicted bertha armyworm development
• Predicted wheat midge development
• Weekly wind trajectory report
• Field heroes NEW Pest & Predator podcast links
• Provincial entomologist updates
• Links to crop reports
• Previous posts
….and catch Monday’s Insect of the Week for Week 5 – it’s the sugarbeet wireworm, Limonius californicus!

Wishing everyone good weather!

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Questions or problems accessing the contents of this Weekly Update?  Please contact us so we can connect you to our information. Past “Weekly Updates” can be accessed on our Weekly Update page.

Weather synopsis

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.

Figure 1. Seven-day average temperature (°C) across the Canadian prairies for the period of May 30-June 5, 2022.

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).

Figure 2. 30-day average temperature (°C) across the Canadian prairies for the period of May 7-June 5, 2022.
Figure 3. 30-day average temperature anomaly (°C difference from climate normals) observed across the Canadian prairies for the period of May 7-June 5, 2022.

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.

Figure 4. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1 to June 5, 2022.

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.

Figure 5. Seven-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 30-June 5, 2022.

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).

Figure 6. 30-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (May 29-June 5, 2022).
Figure 7. Growing season cumulative rain anomaly (% if climate normals) observed across the Canadian prairies for the period of May 7-June 5, 2022.

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).

Figure 8. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1 to June 5, 2022.

Growing degree day (GDD) maps for Base 5 ºC and Base 10 ºC (April 1-June 6, 2022) can be viewed by clicking the hyperlinks. Over the past 7 days (May 31-June 6, 2022), the lowest temperatures recorded across the Canadian prairies ranged from < -4 to >8 °C while the highest temperatures observed ranged from <6 to >24 °C. Some areas of the prairies hit warmer temperatures with a slight bump in the number of sites experiencing days at or above 25 °C across the prairies – a maximum of 4 days. Access these maps and more using the AAFC Maps of Historic Agroclimate Conditions interface.

The maps above are all produced by Agriculture and Agri-Food Canada. Growers can bookmark the AAFC Current Conditions Maps for the growing season. Historical weather data can be accessed at the AAFC Drought Watch Historical website, Environment Canada’s Historical Data website, or your provincial weather network. The AAFC Canadian Drought Monitor also provides geospatial maps updated monthly.

Predicted grasshopper development

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.

Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development (%) across the Canadian prairies as of June 5, 2022.
Figure 2. Predicted grasshopper (Melanoplus sanguinipes) hatch (%) across the Canadian prairies as of June 5, 2022.

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.

Figure 3. Predicted risk for the migratory grasshopper (Melanoplus sanguinipes) across the Canadian prairies as of June 5, 2022.

Grasshopper Scouting Tips:
Review grasshopper diversity and photos of nymphs, adults, and non-grasshopper species to aid in-field scouting from egg hatch and onwards.
● Access the PPMN’s Grasshopper Monitoring Protocol as a guide to help implement in-field monitoring.
● Review grasshopper lifecycle, damage and scouting and economic thresholds to support sound management decisions enabling the preservation of beneficial arthropods and mitigation of economic losses.

Biological and monitoring information (including tips for scouting and economic thresholds) related to grasshoppers in field crops is posted by Manitoba Agriculture and Resource DevelopmentSaskatchewan AgricultureAlberta Agriculture and Forestry, the BC Ministry of Agriculture, and the Prairie Pest Monitoring Network.  Also, refer to the grasshopper pages within 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.

Predicted alfalfa weevil development

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.

Figure 1. Predicted status of alfalfa weevil (Hypera postica) populations near Winnipeg MB as of June 5, 2022.
Figure 2. Predicted status of alfalfa weevil (Hypera postica) populations near Medicine Hat AB as of June 5, 2022.

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.

Predicted cereal leaf beetle development

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.

Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge AB as of June 5, 2022.
Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Brandon MB as of June 5, 2022.

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.

Predicted bertha armyworm development

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.

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development (%) across the Canadian prairies as of June 5, 2022.

Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting or eview the 2019 Insect of the Week which featured bertha armyworm and its doppelganger, the clover cutworm! 

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” (2018) accessible as a free downloadable PDF in either English or French on our new Field Guides page.

Predicted wheat midge development

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.

Figure 1. Percent of wheat midge larval population (Sitodiplosis mosellana) that has moved to the soil surface across western Canada, as of June 5, 2022.

Information related to wheat midge biology and monitoring can be accessed by linking to your provincial fact sheet (Saskatchewan Agriculture or Alberta Agriculture & Forestry).  Alberta Agriculture and Forestry has a YouTube video describing in-field monitoring for wheat midge.  

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.

Weekly Wind Trajectory Report for June 6

Access background information on how and why wind trajectories are monitored. Reverse and forward trajectories are available in this report.

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.

Figure 1. Average number (based on a 5-day running average) of reverse trajectories (RT) crossing the prairies for the period of May 1-June 6, 2022.

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).

Figure 2. Total number of dates with reverse trajectories originating over the Idaho, Oregon, and Washington that have crossed the prairies between April 1 and June 6, 2022.

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).

Figure 3. The total number of dates with reverse trajectories originating over Mexico, California and Texas that have crossed the prairies between April 1 and June 6, 2022.

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).

Figure 4. The total number of dates with reverse trajectories originating over Texas and Oklahoma that have crossed the prairies between May 1 and June 6, 2022.

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).

Figure 5. The total number of dates with reverse trajectories originating over Kansas and Nebraska that have crossed the prairies between April 1 and June 6, 2022.

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.

Figure 6. Total number of dates with forward trajectories, originating from various regions of the United States and Mexico, crossing the prairies between April 1 and June 6, 2022.

View historical PPMN wind trajectory reports by following this link which sorts the reports from most recent to oldest.

Provincial insect pest report links

Provincial entomologists provide insect pest updates throughout the growing season so link to their information:

MANITOBA’S Crop 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.

SASKATCHEWAN’S Crop Production News for 2022 is up and running! Access the online Issue #1 for May 24-30, 2022 here. Bookmark their insect pest homepage to access important information! Crops Blog Posts are updated through the growing season.
Diamondback moth pheromone trap monitoring update for SK – Access this link to review counts summarized regionally. So far, “diamondback moth is arriving in Saskatchewan, but numbers are currently low”.

ALBERTA’S Insect 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.

Crop report links

Click the provincial name below to link to online crop reports produced by:
Manitoba Agriculture and Resource Development (or access a PDF copy of the June 7, 2022 report).
Saskatchewan Agriculture (or access a PDF copy of the May 31-June 6, 2022 report).
Alberta Agriculture and Forestry (or access a PDF copy of the May 31, 2022 report).

The following crop reports are also available:
• The United States Department of Agriculture (USDA) produces a Crop Progress Report (access a PDF copy of the June 6, 2022 edition).
• The USDA’s Weekly Weather and Crop Bulletin (access a PDF copy of the June 7, 2022 edition).

Previous posts

As the growing season progresses, the various Weekly Update topics move on and off the priority list for in-field scouting but they should be kept at hand to support season-long monitoring. Click to review these earlier 2022 Posts (organized alphabetically):
2021 Risk and forecast maps
Crop protection guides (Wk02)
Cutworms (Wk02)
European corn borer – Canadian standardized assessment 2.0 (Wk02)
Field heroes (Wk04)
Field guides – New webpage to access (Wk02)
Flea beetles (Wk01; IOTW)
iNaturalist.ca (Wk02)
Invasive insect species – Early detection (Wk02)
Scouting charts – canola and flax (Wk03)
Ticks and Lyme disease (Wk02)
Wind trajectory reports released in 2022
Wireworms – New field guide (Wk02)