Released June 17, 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 Monday’s Insect of the Week for Week 6 – it’s the flat wireworm, Aeolus mellillus!

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. Rainfall has been below normal for Alberta and western Saskatchewan while rainfall amounts have been well above normal for eastern Saskatchewan and Manitoba. This past week (June 6-12, 2022) average daily temperatures were generally warmer than in the previous week. The warmest conditions occurred across southern Manitoba, a region extending from Regina to Saskatoon and southwest to Lethbridge, and in the northern Peace River region (Fig. 1). The average temperature across the prairies was 2 °C warmer than normal.

Figure 1. Seven-day average temperature (°C) across the Canadian prairies for the period of June 6-12, 2022.

Though the prairie-wide average 30-day temperature (May 14 – June 12, 2022) was similar to the long-term average value, the average was 1.5 °C warmer than the previous week. Average temperatures have increased across most of the prairies (Fig. 2).

Figure 2. 30-day average temperature (°C) across the Canadian prairies for the period of May 14-June 12, 2022.

The prairie-wide average growing season (April 1-June 12, 2022) temperature was 1 °C warmer than last week; the average growing season temperature for the prairies has been 1 °C cooler than climate normal values. The growing season continues to be cooler in Manitoba than Saskatchewan and Alberta (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.

Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1 to June 12, 2022.

PRECIPITATION: Seven-day cumulative rainfall ranged between 0 and 42 mm across the prairies, with highest rainfall amounts (20-40 mm) occurring in a region extending from Hanna to Calgary and south to Lethbridge (Fig. 4). Rainfall amounts were generally less than 10 mm for most of Saskatchewan.

Figure 4 Seven-day cumulative rainfall (mm) observed across the Canadian prairies for the period of June 6-12, 2022.

30-day accumulation amounts have been well above average across Manitoba but well below normal across southern and western Saskatchewan (Fig. 5). Growing season rainfall for April 1 – June 12, 2022, continues to be greatest across Manitoba and eastern Saskatchewan; rain amounts have been below normal across most of western Saskatchewan and Alberta (Fig. 6).

Figure 5. 30-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (May 14-June 12, 2022).
Figure 6. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1 to June 12, 2022.

Growing degree day (GDD) maps for Base 5 ºC and Base 10 ºC (April 1-June 13, 2022) can be viewed by clicking the hyperlinks. Over the past 7 days (June 7-13, 2022), the lowest temperatures recorded across the Canadian prairies ranged from < -1 to >9 °C while the highest temperatures observed ranged from <17 to >28 °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 yet no sites have recorded days at or above 30 °C. 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 12, 2022. Warmer temperatures over the past 30 days have resulted in increased rates of grasshopper development across Saskatchewan and Alberta; wetter/cooler conditions across eastern Saskatchewan and Manitoba have resulted in delayed development.

Last week, average embryological development was 76 %. This week, average egg development is predicted to be 83 % and is 1 % greater than the long-term development rate. Hatch is progressing across southern and central regions of Alberta and Saskatchewan with hatch rates that range between 15 and 60% (Fig. 1). First to third instar nymphs should be occurring across southern and central regions of Alberta and Saskatchewan. Simulations indicate that 5-10% of the population has hatched across southern and central regions of Manitoba.

Figure 1. Predicted grasshopper (Melanoplus sanguinipes) embryological development (%) across the Canadian prairies as of June 12, 2022.

Risk estimates, based on meteorological inputs, were used to assess the impact of weather on grasshopper development and population growth potential (Fig. 2). Grasshopper risk is greatest in areas that are warmer and drier than normal. As of June 12, 2022, model output indicates that potential risk is greatest across a region that extends from Lethbridge to Swift Current and Saskatoon. Relative to last week, risk has increased for localized areas across the Peace River region. The simulation indicates that even though temperatures are suitable for grasshopper development, excessive moisture across most of Manitoba has reduced the potential risk from grasshoppers. Overall risk is predicted to be similar to long-term average risk and is currently well below potential risk predictions that were produced for the 2021 growing season. 

Figure 2. Predicted risk for the migratory grasshopper (Melanoplus sanguinipes) across the Canadian prairies as of June 12, 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 third instar larvae should now be appearing across the prairies. Development is similar to long-term average values. AAW development in central Saskatchewan (Fig. 1) is slower than AAW development in southern Alberta (Fig. 2).

Figure 1. Predicted status of alfalfa weevil (Hypera postica) populations near Saskatoon SK as of June 12, 2022.
Figure 2. Predicted status of alfalfa weevil (Hypera postica) populations near Medicine Hat AB as of June 12, 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 western Saskatchewan are predicted to result in more rapid development of cereal leaf beetle (CLB) populations in those regions than in southern Manitoba. CLB model output predicts that hatch should be nearly complete for southern Alberta and western Saskatchewan. First to third instar larvae are predicted to be present in these areas (Fig. 1). As a result of cooler conditions, the model predicts that egg development has been delayed in southern Manitoba; first instar and second instar larvae may be appearing this week (Fig. 2).

Figure 1. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Lethbridge AB as of June 12, 2022.
Figure 2. Predicted status of cereal leaf beetle (Oulema melanopus) populations near Winnipeg MB as of June 512 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

Pupal development of bertha armyworm (BAW) is progressing across the prairies with the most rapid development occurring across southern and central regions of Alberta and western Saskatchewan (Fig. 1). Over the next week, adults should be emerging across Alberta, Saskatchewan and localized areas in southern Manitoba.

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development (%) across the Canadian prairies as of June 12, 2022.

Use the images below (Fig. 2) to help identify moths from the by-catch that will be retained in the green 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)

Refer to the PPMN Bertha armyworm monitoring protocol for help when performing in-field scouting or review 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 but soil moisture conditions in May and June largely determine whether or not the larva exits their cocoon to move to the soil surface to continue development (i.e., to pupate then emerge as a midge this season). 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. Wheat midge emergence may be delayed or erratic if rainfall does not exceed 20-30 mm during May. 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

Compared to last week, the wheat midge model indicates that the development of larval populations has advanced considerably across the eastern prairies and Peace River region. Normal to above-normal rain in Manitoba, eastern Saskatchewan and the Peace River region should be sufficient to promote the movement of wheat midge larvae to the soil surface (Fig. 1). Insufficient rainfall across central Alberta and western Saskatchewan will limit the development of larval populations that are in the soil.

Wheat midge simulations suggest that greater than 60 % of the larval population has moved to the soil surface in some areas of the prairies. Larval populations should begin to transition to the pupal stage 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 12, 2022.

Risk estimates, based on meteorological inputs, were used to assess the impact of weather on wheat midge development and potential population growth potential (Fig. 2). Wheat midge risk is greatest in areas that have received normal to above-normal rainfall. As of June 12, 2022, model output indicates that potential risk is greatest across eastern Saskatchewan and Manitoba. Risk in these areas is predicted to be similar to long-term average risk.

Figure 2. Predicted risk for wheat midge (Sitodiplosis mosellana) outbreaks across the Canadian prairies as of June 12, 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.

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 15, 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!
Flea beetles, cutworms and grasshopper nymphs in MB – Review the above June 15 issue to find greater details but the summary reads as, “Flea beetles levels are at quite high levels in many areas. Some growers have applied up to three insecticide applications for flea beetles, and there has been some reseeding. Some fields of small grains and sunflowers have been sprayed for cutworms. Hatch of the potential pest species of grasshoppers is occurring; some control has occurred in the Central region.”
Diamondback moth pheromone trap monitoring update for MB – “So far, diamondback moth has been found in 29 traps.” Read the report on Page 5 of the June 15, 2022 issue OR review a more detailed summary of cumulative trap counts from 48 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 6of the June 15, 2022 issue.

SASKATCHEWAN’S Crop Production News for 2022 is up and running! Access the online Issue #2 (June 2022) here and find updates linking to Canola Watch’s 8-steps for making the flea beetle spray decision, details for early season grasshoppers plus descriptions of invasive fruit insect surveys and wireworms as a potential cause of poor emergence, 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 continue to come in so refer to the Live Map to review areas where cutworms are being found. So far, black army, pale western, and dingy 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 14, 2022 report).
Saskatchewan Agriculture (or access a PDF copy of the June 7-13, 2022 report).
Alberta Agriculture and Forestry (or access a PDF copy of the June 7, 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 13, 2022 edition).
• The USDA’s Weekly Weather and Crop Bulletin (access a PDF copy of the June 14, 2022 edition).

Field heroes

The Field Heroes campaign continues to raise awareness of the role of beneficial insects in western Canadian crops.

Field Heroes resources include:

  1. Real Agriculture went live in 2022 with Season 3 of the Pest and Predators podcast series!
    NEW Episode 17 – Spiders and their amazing appetites Carol Frost (University of Alberta) and Shaun Haney (RealAg). Published online June 14, 2022.
    • Episode 16 – Parasitoids prey on pests in pulses Nevin Rosaasen (Alberta Pulse Growers) and Shaun Haney (RealAg). Published online May 31, 2022.
    • Episode 15 – Aphid milkshakes: Green lacewing’s fave Tyler Wist (Agriculture and Agri-Food Canada-Saskatoon) and Shaun Haney (RealAg). Published online May 17, 2022.
    • Episode 14 – Mistaken identities: Insect pest or beneficial? John Gavloski (Manitoba Agriculture and Resource Development) and Shaun Haney (RealAg). Published online May 3, 2022.
    • Episode 13 – Weather effects: Predicting pest populations James Tansey (Saskatchewan Ministry of Agriculture), Meghan Vankosky (Agriculture and Agri-Food Canada-Saskatoon), and Shaun Haney (RealAg). Published online April 19, 2022.
    • Review SEASON 2 of the Pest and Predators podcasts!
    • Review SEASON 1 of the Pest and Predators podcasts!
  2. The Pests and Predators Field Guide is filled with helpful images for quick insect identification and plenty of tips to manage the pests AND natural enemies in your fields. Claim your free copy at http://fieldheroes.ca/fieldguide/ or download a free copy to arm your in-field scouting efforts!
  3. Review the Sweep-net Video Series including:
    How to sweep a field. Meghan Vankosky (Agriculture and Agri-Food Canada-Saskatoon). Published online 2020.
    What’s in my sweep-net? Meghan Vankosky (Agriculture and Agri-Food Canada-Saskatoon). Published online 2020.
    Why use a sweep-net? Meghan Vankosky (Agriculture and Agri-Food Canada-Saskatoon). Published online 2020.

Follow @FieldHeroes!

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)