Weekly Update

Week 1 for the 2022 growing season and welcome back!

Seeders AND the many field crop entomologists across the Canadian prairies are out and raring to go for another growing season! This week….

Please take a moment to review the historical Risk Maps for our most economically important insect pests of field crops on the Canadian prairies. These prairie-wide geospatial maps offer insight into potential risk and help growers prioritize their scouting lists.

Remember, insect Monitoring Protocols containing helpful insect pest biology, how and when to target in-field scouting, and even thresholds to help support in-field management decisions are all available for review or download.

NEW for this growing season – the website has been updated to create a Field Guides page linking to free, downloadable, AND searchable PDF copies of some of the key field guides used to support in-field insect monitoring in field crops on the Canadian prairies.

Be sure to catch this week’s earlier Insect of the Week for Week 1- it’s Flea beetles!

Wishing everyone good weather and let the insect scouting begin!

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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: Since April 1, the 2022 growing season has been cooler and wetter than normal. This past week (May 2-8, 2022), the average temperature across the prairies was 1.1 °C cooler than normal (Fig. 1). The average 30-day temperature (April 9-May 8, 2022) was 3 °C lower than climate normal values (Fig. 1). Temperatures have been coolest in Manitoba (Figs. 1, 2).

Figure 1. 30-day average temperature (°C) observed across the Canadian prairies for the period of April 9– May 8, 2022.
Figure 2. Seven-day average temperature (°C) across the Canadian prairies for the period of May 2-8, 2022.

Growing degree day (GDD) maps for Base 5 ºC and Base 10 ºC (April 1-May 9, 2022) can be viewed by clicking the hyperlinks. Over the past 7 days (May 3-9, 2022), the lowest temperatures recorded across the Canadian prairies ranged from < -12 to >0 °C while the highest temperatures observed ranged from <10 to >25 °C. Even at this early point in the growing season, a few areas in Alberta and Saskatchewan have experienced 1-2 days >25 °C (view map). Access these maps and more using the AAFC Maps of Historic Agroclimate Conditions interface.

PRECIPITATION: Average seven-day cumulative rainfall ranged between 0 and 66 mm with the highest rainfall amounts occurring in the Peace River region of Alberta and British Columbia (Fig. 3). The remainder of the prairies received little or no rain. Rain (30-day accumulation) amounts have been well above average for most of the prairies (255 % of average). Rainfall for April 9-May 8, 2022 was greatest across Manitoba and conditions have been drier across most of Saskatchewan and Alberta (Fig. 4).

Figure 3. Seven-day cumulative rainfall (mm) observed across the Canadian prairies for the period of May 2-8, 2022.
Figure 4. 30-day cumulative rainfall (mm) observed across the Canadian prairies for the period of April 9-May 8, 2022.

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 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.

As of May 8, model simulations for alfalfa weevil (AAW) predict that oviposition is well underway across the prairies. The following graphs indicate, based on the potential number of eggs, that development is slower near Lethbridge (Fig. 1) than Saskatoon (Fig. 2). Development for both locations is ahead of that expected based on long-term averages. The model predicts that hatch may occur during the last week of May.

Figure 1. Predicted status of alfalfa weevil (Hypera postica) populations near Lethbridge AB as of May 8, 2022.
Figure 2. Predicted status of alfalfa weevil (Hypera postica) populations near Saskatoon SK as of May 8, 2022.

Alfalfa growers are encouraged to check the Alfalfa Weevil Fact Sheet prepared by Dr. Julie Soroka (AAFC-Saskatoon).  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.

As of May 8, 2022, the model output suggests that overwintered adults are active and that oviposition is underway across the southern regions of Alberta and in southwestern western Saskatchewan. Compared to simulations for climate normals, development in 2022 is generally slower than average. The graphs provide a comparison of development for Lethbridge (Fig. 1) and Swift Current (Fig. 2).

Warmer conditions in southern Alberta are predicted to result in more rapid development of CLB populations in comparison to southern Saskatchewan. The simulation indicates that first instar larvae may occur during the third week of May.

Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge AB as of May 8, 2022.
Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Swift Current SK as of May 8, 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 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.

As of May 8, 2022, the model simulation indicates that egg development is most advanced in southern Alberta (Fig. 1). Cool conditions in Manitoba have resulted in slower development rates. Egg development is expected to range from 50 and 65 % across most of the prairies (average = 59 %). Based on climate normals data, long-term average development should be 57 % (Fig. 2).

Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian prairies as of May 8, 2022.
Figure 2. Predicted grasshopper (Melanoplus sanguinipes) embryological development across the Canadian prairies as of May 8 based on long-term average (climate normals) data.

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” (accessible in either English-enhanced or French-enhanced versions).

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 will be available soon. Be sure to bookmark their Crop Pest Update Index to readily access these reports! Bookmark their insect pest homepage to access fact sheets and more!

SASKATCHEWAN’S Crop Production News normally includes 7 issues released through the growing season. Be sure to bookmark their insect pest homepage to access important information!

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.

Crop report links

Click the provincial name below to link to online crop reports produced by:
Manitoba Agriculture and Resource Development (subscribe to receive OR access a PDF copy of the May 10, 2022 report).
Saskatchewan Agriculture (or access a PDF copy of the May 3-9, 2022 report).
Alberta Agriculture and Forestry (or access a PDF copy of the May 3, 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 May 9, 2022 edition).
• The USDA’s Weekly Weather and Crop Bulletin (access a PDF copy of the May 10, 2022 edition).