Released June 24, 2022

This week includes…..

• Weather synopsis
• Predicted grasshopper development
• Predicted bertha armyworm development
• Predicted wheat midge development
• Weekly wind trajectory report
• Provincial entomologist updates
• Links to crop reports
• Previous posts
….and Monday’s Insect of the Week for Week 7 – it’s the soybean aphid, Aphis glycines!

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: This past week (June 13-19, 2022) the average daily temperature (prairies) was 1 °C warmer than the previous week and 1.5 °C warmer than normal (Fig. 1). Though the prairie-wide average 30-day temperature (May 21 – June 19, 2022) was similar to long-term average values, the average 30-day temperature for May 21 to June 19 was 1.5 °C warmer than the average 30-day temperature for May 14 to June 12 (Fig. 2).

Figure 1. Seven-day average temperature (°C) across the Canadian prairies for the period of June 13-19, 2022.
Figure 2. 30-day average temperature (°C) across the Canadian prairies for the period of May 21-June 19, 2022.

The growing season (April 1 – June 19, 2022) temperature for the prairies has been 1 °C cooler than climate normal values. The growing season has been warmest across western Saskatchewan and the southern and central regions of Alberta (Fig. 3; Table 1).

Figure 3. Growing season average temperature (°C) observed across the Canadian prairies for the period of April 1 to June 19, 2022.
Table 1. Growing season (April 1 – June 19, 2022) temperature and rainfall summary for specific locations across the Canadian prairies.

PRECIPITATION: Weekly (June 13-19) rainfall varied across the prairies. Significant rainfall was reported across Alberta (Fig. 4). Rainfall amounts were generally less than 10 mm for most of Saskatchewan. 30-day accumulation amounts have been well above average across large areas of Manitoba and Alberta while rainfall accumulation has been well below normal across Saskatchewan (Fig. 5).

Figure 4 Seven-day cumulative rainfall (mm) observed across the Canadian prairies for the period of June 13-19, 2022.
Figure 5. 30-day cumulative rainfall (mm) observed across the Canadian prairies the past 30 days (May 21-June 19, 2022).

Growing season rainfall for April 1 to June 19, 2022, continues to be greatest across Manitoba and southeastern Saskatchewan; rain amounts have been below normal across central Saskatchewan and near normal for Alberta (Fig. 6; Table 1).

Figure 6. Growing season cumulative rainfall (mm) observed across the Canadian prairies for the period of April 1 to June 19, 2022.

Growing degree day (GDD) maps for Base 5 ºC and Base 10 ºC (April 1-June 20, 2022) can be viewed by clicking the hyperlinks. Over the past 7 days (June 14-20, 2022), the lowest temperatures recorded across the Canadian prairies ranged from < -2 to >10 °C while the highest temperatures observed ranged from <21 to >36 °C. Again this week, 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 but little increase in the sites recording 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. Model outputs provided below as geospatial maps are a tool to help time in-field scouting on a regional scale but local development can vary and is only accurately assessed through in-field scouting.

Review lifecycle and damage information for this pest to support in-field scouting.

Model simulations were used to estimate percent grasshopper egg development and hatch as of June 19, 2022. Warmer temperatures across the southern prairies have resulted in increased rates of grasshopper egg development and hatch is now well underway. Egg hatch may be nearly complete for some regions.

Last week, the average embryological development was 83 %. This week, average egg development is predicted to be 90 % and is 2 % greater than the long-term development rate for this time in the growing season. Hatch is progressing across the prairies, with southern and central regions of Alberta and Saskatchewan having hatch rates greater than 75% (Fig. 1). Compared to last week, recent warm conditions across southern Manitoba have resulted in higher hatch rates.

Figure 1. Predicted migratory grasshopper (Melanoplus sanguinipes) hatch (%) across the Canadian prairies as of June 19, 2022.

Based on estimates of average nymphal development, first to third instar nymphs should be occurring across southern and central regions of Alberta and Saskatchewan (Fig. 2). Warm, dry conditions across central and southern regions of Saskatchewan have resulted in rapid grasshopper development.

Figure 2. Predicted migratory grasshopper (Melanoplus sanguinipes) development, presented as average instar, across the Canadian prairies as of June 19, 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. Review the historical grasshopper maps based on late-summer in-field counts of adults performed across the prairies.

Predicted bertha armyworm development

Compared to long-term averages, bertha armyworm (BAW) development has been delayed thus far in the 2022 growing season. Pupal BAW development is progressing across the prairies. This week, pupal development is predicted to complete and adult emergence is expected to occur across most of the prairies (Fig. 1). Adult emergence should have already begun across a region extending from Lethbridge to Regina and north to Saskatoon. Adult emergence near Regina, Saskatchewan (Fig. 2) is predicted to be one week ahead of central Alberta (Fig. 3). Oviposition should begin over the next 7-10 days.

Figure 1. Predicted bertha armyworm (Mamestra configurata) pupal development (%) across the Canadian prairies as of June 19, 2022.
Figure 2. Predicted bertha armyworm (Mamestra configurata) populations near Regina, Saskatchewan as of June 19, 2022 (projected to June 30, 2022, based on long-term average conditions).
Figure 3. Predicted bertha armyworm (Mamestra configurata) populations near Lacombe, Alberta as of June 19, 2022 (projected to June 30, 2022, based on long-term average conditions).

Use the images below (Fig. 4) to help identify moths from the by-catch that will be retained in the green phermone-baited unitraps.

Figure 4. 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

Soil moisture conditions in May and June can have significant impacts on wheat midge emergence. Where wheat midge cocoons are present in soil, the 2022 growing season’s rainfall during May and June should be sufficient to terminate diapause and induce the larvae to move to the soil surface. The map in Figure 1 provides a visual representation of regional estimates of wheat midge movement to the soil surface, where pupal development will occur, then adults will begin to emerge. Remember – the rate of development and timing of adult midge emergence varies at the field level and can only be verified through in-field scouting. Fields within regions receiving sufficient rainfall should soon scout! Midge flight coinciding with the beginning of anthesis is a crucial point when in-field counts of wheat midge on plants are carefully compared to the economic thresholds.

As of June 19, 2022, wheat midge development is predicted to be most advanced in eastern Saskatchewan and the western Peace River region (British Columbia) (Fig. 1). The model was projected to July 10 (based on long-term average conditions) to predict potential wheat midge stages in early July. Simulations indicate that midge development will be more advanced at Estevan, Saskatchewan (Fig. 2) and Melfort, Saskatchewan (Fig. 3), than at Grande Prairie, Alberta (Fig. 4). Adults should begin to emerge in late June or early July.

Figure 1. Percent of wheat midge larval population (Sitodiplosis mosellana) that have moved to the soil surface across western Canada, as of June 19, 2022.
Figure 2. Predicted development of wheat midge (Sitodiplosis mosellana) populations near Estevan, Saskatchewan, as of June 19, 2022 (projected to July 10, 2022, based on long-term average conditions)
Figure 3. Predicted development of wheat midge (Sitodiplosis mosellana) populations near Melfort, Saskatchewan, as of June 19, 2022 (projected to July 10, 2022, based on long-term average conditions)
Figure 3. Predicted development of wheat midge (Sitodiplosis mosellana) populations near Grande Prairie, as of June 19, 2022 (projected to July 10, 2022, based on long-term average conditions)

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 20

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 have originated from the Pacific Northwest (Idaho, Oregon and Washington). The number of incoming trajectories during the first two weeks of June was much lower than this past week (June 14-20, 2022) (Fig. 1). The number of reverse trajectories, originating from Mexico, California, Texas, Oklahoma, Nebraska and Kansas have significantly increased since June 18th.

Figure 1. Average number (based on a 5-day running average) of reverse trajectories (RT) crossing the prairies for the period of June 1-20, 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 (June 14-20, 2022) the ECCC model predicted that 124 reverse trajectories would cross the prairies. This is similar to the number of reverse trajectories expected in the previous week (n=134).

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 20, 2022.

b. Mexico and southwest USA (Texas, California) – Prior to this past week, the most recent reverse trajectories that originated from Mexico, California or Texas crossed over the Canadian prairies on May 31st. This week a total of 44 reverse trajectories were predicted to cross the prairies. Most reverse trajectories have entered Manitoba during the 2022 growing season. This week trajectories crossed Medicine Hat, Kindersley, and Swift Current.

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 20, 2022.

c. Oklahoma and Texas – Since April 1, reverse trajectories were reported for Manitoba and eastern Saskatchewan. This week, a number of these reverse trajectories passed over central Saskatchewan, including Saskatoon, Moose Jaw and Regina (Fig. 4). This week there were significantly more (n=44) reverse trajectories than last week (n=1) that originated from Texas and Oklahoma.

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 20, 2022.

d. Nebraska and Kansas – Similar to last week, a number of reverse trajectories originating from Kansas and Nebraska have crossed central and western prairie locations (Fig. 5). This past week (June 14-20, 2022) the ECCC model predicted that 51 reverse trajectories passed over the prairies. This is a significant increase from the previous week (n=8).

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 20, 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 (June 14-20, 2022) there was an increase in the number (n=50) of forward trajectories predicted to cross the prairies (n=34 last week). 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 20, 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 22, 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!
Grasshopper nymphs, lygus bugs, pea leaf weevils in MB were new additions to the June 22 issue.
Diamondback moth pheromone trap monitoring update for MB – “So far, diamondback moth has been found in 33 traps.” Read the report on Page 5 of the June 22, 2022 issue OR review a more detailed summary of cumulative trap counts from 51 sites deployed across the province.
Armyworm pheromone trap monitoring is underway in MB – Review the current cumulative counts in the June 22, 2022 issue and find a link to review a map of counts compiled from Manitoba, Eastern Canada and several northeast states of the United States.

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.
Bertha armyworm 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 bertha armyworm moths have been intercepted across the province.
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. 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 21, 2022 report).
Saskatchewan Agriculture (or access a PDF copy of the June 14-20, 2022 report).
Alberta Agriculture and Forestry (or access a PDF copy of the June 14, 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 21, 2022 edition).
• The USDA’s Weekly Weather and Crop Bulletin (access a PDF copy of the June 22, 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
Alfalfa weevil – predicted development (Wk06)
Cereal leaf beetle – predicted development (Wk06)
Crop protection guides (Wk02)
Cutworms (Wk02)
European corn borer – Canadian standardized assessment 2.0 (Wk02)
Field heroes (Wk06)
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